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Keston K50 Installation Manual

1. HV PK PINK N INCOMINGNEUTRAL W WHITE G GREEN INCOMINGEARTH BR BROWN V VIOLET YJ G YELLOW GREEN o 31211109 8 e 5 4 3 2 1 _ 2 92 08 i 5 GAS SWITC H oO EEN a re 5 zi APS 91 OR N lt BLOWER ay FLUE OVERHEAT A ey M X GREEN THERMOSTAT LAMP o GAS VALVE E AN 1 7 128 WATER PRESSURE L 12 SWITC H ede 11 Ha Gp __ 5 RED 10 10 BK FLOW HIGH EMIT um d 96 THERMOSTAT 9 a THERMAL FUSE au N ii W 5 6 B 5BR 5 FLOW OVERHEAT B 4 1 THERMOSTAT 4 59PK L 3 N eu FILTER p L L ON OFF B OILER Va d 2 L SWTCH THERMOSTAT 1 5 Installation amp Servicing Instructions Page 33 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers 5 6 ILLUSTRATED WIRING DIAGRAM ILLUSTRATED WIRING DIAGRAM Overheat Stat Thermal Fuse RAM Control 59PK 52BK 56R Boiler Stat Flow High Limit 9 G 2 4 SA zor 9208 Low Water Pressure Switch Gas Low 10BK Pressure Switch 55BR Gas Valve 93R Ignition Electrode Air Pressure Switch Flue Overheat Stat
2. Installation amp Servicing Instructions Page 34 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers 5 7 Exploded Assembly Diagrams 5 7 1 Boiler Controls Assembly K50 05 4 00 00 0 K60 06 4 00 00 0 K80 08 4 00 00 0 FUSE ISOLATOR IGNITION CONTRO SECTION 04 4 20 00 0 04 4 01 00 RAM 04 4 01 00 FUSE SOCKE SCREW 04 4 19 00 0 041 00 840 qv TENTION 04 4 11 00 RAM 04 4 11 00 AIR PRESSURE SWITCH MAUVE 04 4 04 00 0 50 6 BLUE WH 04 4 04 00 1 K8 SCREW 04 4 00 06 0 THERMAL FUS 04 4 18 00 0 SCREW 04 1 00 40 0 SECTION HARNESS PACTROU 04 4 10 00 0 K50 amp PACTROU 08 4 10 00 0 RAM 04 4 10 00 TERMINAL BLOC 04 4 05 00 0 gt A SCREW 04 4 00 10 0 MAINS a SUPRESSOR FITE 04 4 02 00 d TERMINAL BLOC S Je BASE LABE lt 04 4 00 03 04 4 00 04 0 N SECTION NEON BULB 04 4 12 00 0 SECTION ge GAUGE 04 4 09 00 0 GREEN LAMA 04 4 07 00 0 ON OFF SWIC 04 4 06 00 0 KED 04 4 08 00 0 Installation amp Servicing Instructions Page 35 WD50 2 1997 Chapter 5 Fault Findi
3. Table 2 7 7 Pump Selection 2 8 FLUE SYSTEM 2 8 1 Design Individual air supply and flue outlet pipes are used The material used for flue outlet amp or air inlet must be muPVC to BS 5255 and of an internal diameter of 38 mm Both flue outlet terminal and air inlet terminal are supplied and are illustrated in Figure 2 8 1 2 8 2 Maximum Lengths The maximum lengths of both air inlet pipe and flue outlet pipe when no bends are used are as detailed below Maximum Air Inlet Length 10 0 Maximum Flue Outlet Length 10 0 m However each bend used has an equivalent length that must be deducted from the maximum straight length stated above A 92 5 sweep elbow is equivalent to 1 0m straight length Example Air inlet uses two 92 5 sweep elbows Hence maximum length permissible ie a b in figure 2 8 2 10 0m 1 0m 1 0m 8 0m Flue outlet uses one 92 5 sweep elbow Hence maximum length permissible ie c d in figure 7 10 0m 1 0 m 9 0m Installation amp Servicing Instructions Page 13 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers 2 8 3 Slope Horizontal flue outlet pipework MUST slope at least 2 5 degrees 45 mm per metre run downwards towards the boiler Pipework be vertical Only swept elbows can be used Air inlet pipework can be truly horizontal or vertical or sloping in a downward direction towards the
4. 04 2 00 76 0 28 WATER RETURI PIPE 04 2 00 60 CONDENSATE TRAI 04 2 14 00 1 CONDENSATE HOS 04 2 00 48 1 HOSE CLAMP 04 2 00 57 0 Installation amp Servicing Instructions Page 36 WATER PRESSURE SWITCH 04 2 23 00 0 WATER OUT MANIFOLD 04 2 00 32 2 WATER FLOW OU THERMOSTAT 04 2 21 00 SCREW 04 1 00 78 0 FLOW HIGH THERMOSTAT 04 2 22 00 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers 5 7 8 Air Gas Assembly GAS TEE REGULATOR GAS VALVI 04 3 07 00 0 SOLENOID 04 3 07 01 0 AR ORFFICE SCRE 04 3 00 39 0 SECONDARY SOLENOI 04 3 07 03 0 GASKET 04 3 00 20 0 AIR GAS FLEXIBLE TUB 04 3 05 00 1 K50 K6 08 3 05 00 1 K8 SCREW 04 1 00 81 0 SEALING GASKE 04 1 00 38 0 GASKET 04 2 00 33 0 CAPACITOR 04 3 03 00 0 BLOWER 04 3 01 00 0 B LOWER RUBBER ISOLATO 04 3 04 00 0 PRESS 04 2 28 00 0 TEST CONNECTOR BLOC 04 3 07 02 0 AR ADJ SCRE 04 3 10 00 0 AIR GAS MANIFOLD PLU 04 3 00 19 GAS ORIFICE 05 3 00 17 0 K50N 0034017 1 SCREW 04
5. Minimum Maximum L P Gas Pressure LPG pressure must be maintained between 31 5 mbar 12 4 in w g and 37 6 mbar 14 8 in w g while the boiler is running Gas pressures above or below these levels will lead to problems associated with the gas valve s internal pressure regulator Supply pipes to the boiler must not be sized less than the boiler inlet connection 15 mm Due consideration must be given to the supply pressure to other gas appliances in the premises Installation amp Servicing Instructions Page 8 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers ee A gas cock is supplied loose with the boiler This cock should be fitted in the gas line to the boiler as close to the boiler as possible so that it is easily identified as the cock to isolate the boiler 2 7 WATER SYSTEMS All piping must be installed in accordance with all applicable local and Water Supply Bylaws for forced hot water heating systems Consideration must be given to pipe capabilities and pressure drop through the piping Water treatment must be carried out to BS 7593 Treament of Water in Hot Water Central Heating Systems Pump isolating valves must be positioned as close to the pump as possible a b 2 7 1 The Keston is suitable for use on open vented water systems with combined feed and vent It is preferable for use on sealed water systems provided the appropriate components required see Sec
6. Reassemble Section 7 3 NB When re fitting condensate trap pour water into the condensate hose from the base of the heat exchanger until nearly full Then reconnect the condensate hose to the base of the heat exchanger Installation amp Servicing Instructions Page 48 WD50 2 1997 Chapter 7 Replacement Of Parts The Keston 50 60 amp 80 Condensing Boilers w ic c 711 PRESSURE GAUGE Fig 5 7 1 item 119 vi vii Isolate the appliance Section 7 1 and shut off the boiler from the water circuit Gain access Section 7 2 Shut off the pressure measurement point at the return drain valve located at the base of the heat exchanger Remove the phial from its mounting at the return pipe entry to the base of the heat exchanger Press in the catches and push the pressure gauge forward through the control panel Reassemble Section 7 3 Refill the system See Section 4 Commissioning 7 12 SIGHT GLASS Fig 5 7 2 item 49 i i Isolate the appliance Section 7 1 Gain access Section 7 2 Unscrew the sight glass fitting from the burner head Reassemble Section 7 3 7 43 HT IGNITION LEAD Fig 5 7 1 item 120 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the lead from the electrode and the ignition control box Reassemble Section 7 3 7 4 AIR VENT Fig 5 7 2 item 72 i ii iii iv v vi vii viii
7. 04 1 00 54 0 FRONT DOOR SCRE 04 1 00 37 0 WARNING 04 1 00 55 0 SHUTTING CLAM 17 1 09 00 0 SCREW 04 1 00 76 0 SCREW 04 1 00 77 0 Installation amp Servicing Instructions FRONT DOOR 4 1 13 00 0 K50 6 08 1 13 00 0 8 SCREW Sa Chapter 5 Fault Finding 22mmGROMMET 04 1 00 49 0 BURNER ACCESS OW 04 1 00 32 0 04 1 00 49 1 28mm 42mm GROMME 04 1 00 47 0 50 K60 80 The Keston 50 60 amp 80 Condensing Boilers 05 1 00 00 0 06 1 00 00 0 08 1 00 00 0 FLOW LABEL 04 1 00 53 0 1 A 1 WASHER NUT BLOWER PLATH 04 1 00 38 0 04 1 00 39 0 04 1 00 36 0 Page 38 EXHAUST FLUE LABE 04 1 00 52 0 TOP COVER 04 1 09 00 1 HINDER CLAMP 17 1 00 03 2 SCREW 04 1 00 40 0 AR INLET LABE 04 1 00 51 0 NEG PR ADAPTI 04 1 00 62 FILTER 17 1 12 00 0 AR FILTER COVE 04 1 14 00 1 CABLE HOLDER 04 1 00 61 0 NAME PLATE 05 1 00 50 0 K5 06 1 00 50 0 K6 08 1 00 50 0 K8 WASHER 04 1 00 43 0 EARTHING LOCKVASHE 04 1 00 45 0 NUT 04 1 00 42 0 CONTROLS PLATI 04 1 19 00 1 OUTER SHELI 04 1 03 00 0 K50 6 08 1 03 00 0 K8 TEST POINT LABE 04 1 00
8. Isolate the appliance Section 7 1 Gain access Section 7 2 Shut off the water supply to the appliance Gain access Section 7 2 Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger Unscrew the air vent Reassemble Section 7 3 Refill the system See Section 4 Commissioning 7 15 X Orifice Fig 5 7 3 item 87 Isolate the appliance Section 7 1 Gain access Section 7 2 Disconnect the flexible air intake hose from the air inlet manifold Fig 5 7 3 item 102 Unscrew the air orifice grub screw Fig 5 7 3 item 83 to release the air orifice Lift the air orifice from its seat in the air inlet manifold Reassemble Section 7 3 When replacing the air orifice ensure that the new orifice is seated with the chamfer facing upwards Installation amp Servicing Instructions Page 49 WD50 2 1997 Chapter 8 Spare Parts Listings The Keston 50 60 amp 80 Condensing Boilers 8 SHORT SPARE PARTS LIST Item C GC No Part Denomination Item GCNo Part Denomination 22 114 105Air Filter 46 375 523Burner 375 524 375 525 47 51 114 120lgnitor Sensor Probe 56 114 030Flexible Hose Gasket e 64 375 530Boiler Thermostat 70 375 532Flue Thermostat 75 375 533Flow Overheat Thermostat 78 Installation amp Servicing Instructions Pa
9. It may need more frequent inspection according to the condition of the atmosphere in which the air intake terminates Note 6 1 The air filter can be easily blocked if the boiler is running on or near a building site having an excess of airborne dust It is essential with a premix gas burner that the air is clean and free of dust It is the law that any service work must be carried out by competent qualified persons Pre Service Checks It is recommended that an inspection should be carried out prior to shutting down the unit for servicing Remove the front cover by releasing the 2 slotted screws on the top and lifting the cover from the base Front cover located by two pegs The following items should be observed Smooth starting and running of the blower Smooth lighting of the burner Check for leakage of gas gas air or combustion products Check for condensate leaks Check the colour and appearance of the flame A sky blue flame slightly off the burner gauze is normal The burner itself should appear dark Any glow on the burner indicates gauze blockage requiring cleaning an incorrect gas flow or an air intake blockage f Check that the temperature differential between the flow and return pipes is less than 15 C The temperature difference should be between 10 C and 15 C Check for water soundness Inspect the flue vent and air intake pipework Joints must be sound and all pipework well bracketed i Check that there
10. 0 8 0 Gas Orifice Size mm 2 38 2 71 3 43 Recommended Temperature C 101015 10 to 15 10 to 15 Differential Installation amp Servicing Instructions Page 4 1 5 GENERAL DATA Main Burner Gas Control Combustion Fan Direct Spark Ignition Air Pressure Switch Filter Gas Supply Connection Flow Connection Return Connection Power Supply Pwr Consumption Ext Fuse Rating Weight Full Weight Empty Data Badge Posn Water Content Keston 50 Keston 60 WD50 2 1997 vacet 1 General Instruction The Keston 50 60 amp 80 Condensing Boilers Keston 80 Keston Premix Keston Premix Keston Premix White Rogers 36E Series White Rogers 36E Series White Rogers 36E Series Keston Type LPB 102 220 240 0 18 KW 2900 RPM Keston Type LPB 102 220 240 0 18 KW 2900 RPM Keston Type LPB 102 220 240 0 18 KW 2900 RPM RAM Electronics Full Sequence Control RAM Electronics Full Sequence Control RAM Electronics Full Sequence Control Tridelta FS 6717 1428 Tridelta FS 6717 1428 Tridelta FS 6717 1428 Keston Filter Keston Filter Keston Filter 0 5 inch BSPT Male 15mm to gas cock 0 5 inch BSPT Male 15mm to gas cock 0 5 inch BSPT Male 15mm to gas cock 28 mm Copper 28 mm Copper 28 mm Copper 28 mm Copper 28 mm Copper 28 mm Copper 230V 50 Hz 230V 50 Hz 230V 50Hz
11. 2 1 2 J From opening in a car port 1 2 100 K Vertically from terminal on same wall 1 5 1 5 L Horizontally from terminal on same wall 300 300 Table 2 8 4 Minimum Flue Terminations amp Air Inlet Dimensions Clearances From Wall Flue outlet and air inlet termination must be at least 60 mm and 95 mm respectively from the wall face Distance Between Flue Outlet amp Air Inlet There is no maximum the terminations can be on opposite sides of the dwelling if desired Installation amp Servicing Instructions Page 15 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers Ce minimum clearance of at least 350 mm must be left between the terminations 2 8 7 General Installations All parts of the system must be constructed in accordance with BS 5440 Part 1 except where specifically mentioned in these instructions All pipework must be adequately supported All joints other than push on or plastic compression connectors must be made and sealed with solvent cement suitable for muPVC pipes and conforming to BS 6209 1982 External wall faces and any internal faces of cavity walls must be made good 2 9 AIR SUPPLY The Keston is a room sealed appliance and therefore does not require purpose provided ventilation for combustion air 2 10 COMPARTMENT INSTALLATION Where the appliance is installed in a cupboard or compartment no air vents are required The boiler will run suff
12. 231 405 A Top View 254 Figure 2 11 Minimum Clearances Return Flow All dimensions in mm 7P keston50 amp 60 890 Kestan 8o All dimensions are in mm 37 m meme meu oio Y Base View Service Connection Locations Installation amp Servicing Instructions Page 6 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers room containing a bath or shower any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower Compartment installation is permitted such compartments must be constructed in accordance with BS 6798 The wall on which the boiler is mounted must be of suitable load bearing capacity and must be non combustible Important It is not recommended to install the boiler on a studded wall or similar it is possible that the vibration from the fan would be amplified and transmitted to other parts of the house Chimneys not used for venting any other appliance may be used Secure air amp flue pipes at chimney outlet NB Refer to 11 Section 2 8 3 E Figure 2 3 ection co Condensate drain The Keston can be located virtually anywhere desired provided that all regulations are met Because of the boiler s compact size and venting flexibility the installation is not limited to a boiler room
13. flame symbol and the red lockout lamp will be illuminated simultaneously If after three automatic attempts the boiler still fails to ignite the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and the red lockout lamp will remain illuminated If after five manual attempts to allow for purging of any air in the gas line the boiler still fails to ignite indicated by the red lockout lamp refer to Section 5 2 Fault Finding Flow Chart j Check for gas soundness between the gas service cock and connection to the burner manifold Installation amp Servicing Instructions Page 24 WD50 0 1996 Chapter 4 Commissioning The Keston 50 60 amp 80 Condensing Boilers 6 4 6 HOT FLUSHING a Allow the system to heat up checking for water soundness b Follow instructions provided with the cleaning agent ie Fernox Supafloc Turn off the boiler and flush the water system while still hot Thoroughly flush the system with clear water Fig 4 7 GAS VALVE Burner pressure Adjustment Burner pressure test nipple gt Refill the system using a quality water treatment such as Fernox MB1 or Fernox Super Concentrate If aluminium radiators are used then Fernox Copal should be used For sealed systems fill to the required Initial Design Pressure 4 7 CHECKING THE GAS PRESSURE With the boiler running measure the burner pressure at the burner pressure tes
14. is installed to maintain required flow
15. is a steady fall back to the boiler from the flue pipe to allow condensate to run back into the boiler See Section 2 8 3 Slope e j With the boiler operating at a low return temperature i e less than 50 C check that the condensate flows freely from the condensate line 6 1 1 Burner amp Heat Exchanger Blockage Checks i Turn off the boiler amp shut off the gas supply to the boiler ii Remove the pressure point screws from points A amp B Attach a differential gauge iii Turn on the boiler and wait for the fan to reach full speed Obviously the burner will not light iv The pressure difference should be lower than 8 mbar on the Keston 50 8 4 mbar on the Keston 60 and 11 2 mbar on the Keston 80 If not clean the burner Installation amp Servicing Instructions Page 40 WD50 2 1997 Chapter 6 Servicing The Keston 50 60 amp 80 Condensing Boilers Pressure Test Point B Burner Heat From Above vi vii viii xii xiii xiv Flue Pressure Test Point A du d Heat Over heat Exchanger o4 Thermostat Shell Combustion Test Point Pressure Test Point C Fig 6 11 Pressure Test Point Locations Turn off the electrical supply to the boiler Remove the pressure point screw from point C and transfer the tube from point A to C replacing the screw on point A Turn on the electrical supply to the boiler gas still of
16. of system requirements are given in Chapter 2 Section 2 7 Water Systems Connections 28mm copper 3 7 GAS SUPPLY Connect the gas supply to the appliance Details of gas supply requirements are given in Chapter 2 Section 2 6 Gas Supply Connections 0 5 inch BSP male 15mm connection to gas cock 3 8 ELECTRICAL SUPPLY The entry point for the electrical supply cable is in the base of the appliance see Section 2 2 Service Connections fig 2 1 2 via a cordgrip bush Feed the cable through this bush and route inside the cabinet to the connection strip located to the front bottom right of the cabinet 1 The electrical supply must be as specified in Chapter 2 Section 2 4 Electrical Supply WARNING THIS APPLIANCE MUST BE EARTHED 2 All external controls and wiring must be suitable for mains voltage Wiring should be in 3 core PVC insulated cable not less than 24 0 2 mm 0 75mm to BS 6500 Table 16 3 The supply connection must be via a 5 amp fused double pole switch serving only the boiler and system controls Refer to Chapter 2 Section 2 4 Electrical Supply 4 Securely tighten the terminal screws and route the cable through the re openable cable clips Ensure all cables are secured and that the cord grip bush is tightened to securely grip the main cable at entry to the cabinet The mains cable must be connected to the terminals as follows N Blue wire Neutral L Brown wire Live L Yellow Green Wire Earth E
17. panel ii Access to the burner head can be gained by removing the access plate in the top panel of the appliance 7 8 REPLACEMENT PROCEDURES i Always replace in the reverse order unless otherwise stated ii Electrical connections must be remade in accordance with the Wiring Diagram Section 5 5 iii Test the soundness of any gas carrying or water carrying joint broken during the service procedures 7 4 ELECTRICAL COMPONENTS 7 4 4 On Off Switch Fig 5 7 1 item 115 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the push on connectors from the switch taking note of the correct positions iv Press in the catches and push the switch forwards through the control panel v Reassemble Section 7 3 vi Check for correct operation of the switch 7 4 2 Boiler Thermostat Fig 5 7 2 item 64 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the push on connectors from the thermostat taking note of the correct positions iv Unscrew the two retaining screws and remove the thermostat v Reassemble Section 7 3 NB When fitting the new thermostat it is a requirement to smear a thin film of heat sink compound between the thermostat and plate This combined with fitting the new thermostat tightly to the plate ensures a good contact Installation amp Servicing Instructions Page 44 WD50 2 1997 Chapter 7 Replacement Of Parts Keston 50
18. pull off HT lead to the spark ignition electrode Remove the burner head Section 7 7 steps iv to vii Undo the screws to the spark ignition electrode flange located on the burner head and withdraw the spark ignition electrode Reassemble Section 7 3 NB When reassembling inspect the gasket for damage and replace if necessary With the new spark ignition electrode in place it is essential to ensure the gap between the tip of the electrode and the burner surface is 4 mm Distance above or below 4 mm will affect the ignition performance If necessary gently bend the electrode taking care not to damage the ceramic insulator 7 7 BURNER HEAD amp BURNER Fig 5 7 2 items 46 amp 48 i ii iii iv v vi Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the pull off HT lead to the spark ignition flame detection electrode head Remove the four screws retaining the access panel Fig 5 7 4 item 6 and remove the access panel from the top of the cabinet Remove the two allen screws fixing the flange gas air mixture pipe connection to the burner head Remove the four allen screws fixing the burner head to the top of the heat exchanger Withdraw the burner amp burner head from the top of the heat exchanger through the access panel opening in the top of the cabinet Unscrew the burner from the burner head taking care not to damage the burner mesh Reassemble Section 7 3 NB When reassembling insp
19. setting Before locating the boiler near a living space consider whether the sounds generated by the boiler will be objectionable Sound levels from the boiler are no greater than from any other type of high efficiency boiler but even minimal levels may be objectionable if located near a bedroom or in a living area 2 4 ELECTRICAL 2 4 44 Electrical Connections The boiler must be connected to a 230V 50Hz supply fused at 5A All external controls and wiring must be suitable for mains voltage Wiring external tothe boiler must be in accordance with current 1 wiring regulations and local regulations Installation amp Servicing Instructions Page 7 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers method of connection to the mains electricity supply must facilitate complete electrical isolation of the boiler complying with the requirements of BS 1363 The appliance must be connected to the supply via a fused double pole switch having at least 3mm 1 8 inch contact separation in both poles serving only the boiler and the system controls The connection point to the mains supply should be readily accessible and adjacent to the boiler except for rooms containing a bath or a shower Refer to section 2 3 Position 2 4 2 External Wiring amp Controls 1 The boiler is deisgned so that all control wiring is external to the boiler Hence any programmers o
20. the gas valve Unscrew the gas low pressure switch at its connection to the gas control valve body Reassemble Section 7 3 Reset the gas rate See Section 4 Commissioning Installation amp Servicing Instructions Page 46 WD50 2 1997 Chapter 7 Replacement Of Parts Keston 50 60 amp 80 Condensing Boilers G lt 7 4 10 Gas Low Pressure Switch Fig 5 7 3 item 105 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the push on connectors to the gas low pressure switch taking note of the correct positions iv Unscrew the gas low pressure switch from the brass holder v Reassemble Section 7 3 75 GAS ORIFICE Fig 5 7 3 item 91 vi vii viii Isolate the appliance Section 7 1 Gain access Section 7 2 Unscrew and remove the brass plug from the gas outlet block Remove the rubber seal from the injector housing Insert a flat blade screwdriver into the exposed hole and unscrew the gas injector Check the injector is the correct size for the boiler size and fuel type Reassemble Section 7 3 NB When fitting the new gas injector ensure that the injector is screwed fully home past the gas port into the chamber from the gas valve Reset the gas pressure See Section 4 Commissioning 7 6 SPARK IGNITION FLAME DETECTION ELECTRODE Fig 5 7 2 item 51 i ii iii iv v vi Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the
21. though no less detrimental to operation because the boiler itself will absorb and radiate a significant amount of heat Low water volume boilers respond more quickly to a call for heat can be made more compact and lightweight but must have adequate heat delivery systems to avoid short cycling of the burner on the temperature limit control The heat delivery system s output must be equal to or greater than the boiler s output to fully load the boiler or short cycling will occur Likewise pumping rates of water through low water volume boilers must be maintained so that water is moved through the boiler fast enough so as not to reach boiling temperatures The slower the water moves through the boiler the more heat it will absorb and the higher the temperatures will rise Consequently the pump selected must be adequate to maintain that critical flow of water 2 14 DETERMINE RADIATION NEEDED ROOM BY ROOM A radiator or convector s ability to deliver heat is related to the water temperature and the rate of delivery to the unit Most systems in the past have been rated at about 80 C Higher efficiencies can be gained from a condensing boiler if ratings published at lower temperatures are used However this is not imperative With normal 80 C ratings used a condensing boiler will still deliver significantly higher efficencies than a non condensing boiler Lower water temperatures in the system tend to increase the efficiency of the boiler and will he
22. 1 00 76 0 04 3 00 34 1 LOW GAS PRESSURE SWITC 04 3 09 00 0 RUBBER 04 3 00 18 0 SCREW 04 3 00 28 0 AIR INLET FLEX CONNEC TO HOSE CLAM 05 3 00 13 0 501 05 300 13 1 KSOLP 06 3 00 13 0 K60N 06 3 00 13 1 K6OLP 08 3 00 13 0 KBON 08 3 00 13 1 KBOLP GAS INLET GASKE 04 3 00 29 0 NUT 04 3 00 30 0 HIGH PRESS TUB SECTION 1 K50 05 3 00 00 0 K60 06 3 00 00 0 K80 08 3 00 00 0 04 3 00 21 0 043 0015 0 K50 K6 08 3 00 15 0 K8 GAS INLET FLEXIBLE TUB 04 3 08 00 3 AIR ORIFICE 04 3 00 32 0 LOW PRESS TUBE 04 3 00 31 0 SCREW 04 1 00 82 0 AIR GAS MANIFOLD 04 3 06 00 GAS VALVE SCREW 04 3 00 16 0 Installation amp Servicing Instructions Page 37 WD50 2 1997 5 7 4 Casing Assembly GAS VALVE 04 1 18 00 0 EXHAUST TERMINAL 04 1 30 00 0 BRACKET 04 1 00 35 0 SILENCER 04 1 20 00 1 KESTON LABEI 05 1 00 57 0 K5 06 1 00 57 0 K6 08 1 00 57 0 8 ILLUSTRATE WIRING DIAGRAI 04 1 00 56 HEAT EXCHANGE FIXING RO 04 1 00 33 NUT 04 1 00 42 0 WASHER 04 1 00 43 0 FOAM GASKET 04 1 00 48 0 FLAME LABE 04 1 00 60 0 FRONT PANEL 04 1 12 00 0 RETURN LABEI
23. 140W 140W 175 W 5 Amps 5 Amps 5 Amps 46 kg 101 Ibs 46 kg 101 Ibs 52 kg 114 16 44 kg 97 Ibs 44 kg 97 Ibs 50 kg 110 Ibs Rear panel inside case Rear panel inside case Rear panel inside case 2 35 litres 2 35 litres 3 30 litres Installation amp Servicing Instructions Page 5 2 1 2 2 2 3 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers 0 993 2 BOILER LOCATION All dimensions in mm DIMENSIONS AND MINIMUM CLEARANCES The boiler must be installed in minimum clearances shown to allow subsequent servicing and safe operation SERVICE CONNECTIONS Gas water air and flue pipe condensation and electrical connections are as shown Gas 0 5 inch BSP male Flow Return 28 mm copper POSITION The Keston is not suitable for external installation The boiler may be installed in any room or internal space although particular attention is drawn to the requirements of the current IEE Wiring Regulations and in Scotland the electrical provisions of the Building Regulations applicable in Scotland with respect to the installation of the boiler in a room or internal space containing a bath or shower Flue Air Intake Figure 2 12 Dimensions Where a room sealed appliance is installed in a 20201 Z e alin G cece 21 ND
24. 4 4 LP Gas Conversion 4 5 Initial Firing 4 6 Hot Flushing 4 7 Checking The Gas Pressure i WD50 2 1997 4 9 The Keston 50 60 amp 80 Condensing Boilers Timing The Gas Meter Handing Over To The User FAULT FINDING Electrical Control Sequence Fault Finding Flow Chart Continuity Checking Functional Flow Wiring Diagram Electrical Wiring Diagram Illustrated Wiring Diagram Exploded Assembly Diagrams SERVICING Pre Service Checks Recommended Routine Service REPLACEMENT OF PARTS General Precautions Access Electrical Gas Orifice Spark Ignition Flame Detection Electrode Burner Head amp Burner Heat Exchanger Air Filter Condensate Trap Pressure Gauge Sight Glass HT Ignition Lead Air Vent Air Orifice SPARE PARTS LISTINGS Page ii WD50 2 1997 vacet 1 General Instruction The Keston 50 60 amp 80 Condensing Boilers 1 1 1 2 1 GENERAL INSTRUCTION DESCRIPTION The Keston Condensing Boiler is unique in its concept and design While the application for which the boiler was designed is the same as those which other boilers are used the Keston boiler has the added advantage of very high efficiency and small diameter plastic flue which can be extended to 10 metres horizontally or vertically The Keston uses a high power combustion blower to deliver a pre mix of gas and air to a downward firing burner in a high efficiency single pass heat exchanger Normally the combustion t
25. 58 0 ELECTRIC WIRE RETAINER 04 1 16 00 0 GAS INLET 04 1 00 59 0 PLASTIC PLUG 04 1 00 75 0 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers 5 7 5 Exploded Diagrams Parts Reference List Boiler Controls Assembly Fig 5 7 1 GC Number Code Description E01 074 108 Ignition Control Box 170084 110A Air Pressure Switch Keston 80 379 744 110B Air Pressure Switch Keston 50 amp 60 114 076 113 Electrical Terminal Block 114 077 115 On Off Switch 114 078 116 Green Run Lamp 114 079 117 Red Lockout Lamp 114 080 119 Pressure Gauge Waterway Condensate amp Flue Assembly Fig 5 7 2 GC Number Code Description 114 022 43A Heat Exchanger Keston 50 amp 60 114 023 43B Heat Exchanger Keston 80 375 523 46A Burner Keston 50 375 524 46B Burner Keston 60 375 525 46C Burner Keston 80 375 526 47 Burner Head Gasket 114 028 49 Sight Glass 375 527 50 Ignitor Gasket 114 120 51 Spark Ignition Electrode 114 029 54 Pressure Test Nipple 114 032 59 Condensate Trap 114 035 61 Return Drain Valve 375 530 64 Boiler Thermostat 375 532 70 Flue Overheat Thermostat 114 043 73 Combustion Test Plug 114 042 72 Automatic Air Vent 375 533 75 Flow Overheat Thermostat 375 534 78 Flow High Limit Thermostat 114 045 79 Water Pressure Switch Air Gas Assembly Fig 5 7 3 GC Number Code Description 114 046 80 Combustio
26. 60 amp 80 Condensing Boilers 7 4 3 Fig 5 7 1 items 116 amp 117 vi vii Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the neon taking note of the correct positions Press in the catches and push the neon forward through the control panel Pull the centre core of the neon from its housing to expose the bayonet fitting bulb Reassemble Section 7 3 Check for correct operation of the neons 7 4 4 Flow Overheat Fig 5 7 2 item 75 Flow High Limit Fig 5 7 2 item 78 amp Flue Protection Thermostats Fig 5 7 2 item 70 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the thermostat taking note of the correct positions Unscrew the two retaining screws and remove the thermostat Flue protection thermostat only The thermostat seal is maintained via a small O ring between thermostat and flue pipe If this is damaged on removal it must be replaced Reassemble Section 7 3 NB When fitting the new thermostat it is a requirement to smear a thin film of heat sink compound between the thermostat and plate This combined with fitting the new thermostat tightly to the plate ensures a good contact 7 4 5 Water Pressure Switch Fig 5 7 2 item 79 i ii iii iv v vi vii viii Isolate the appliance Section 7 1 Shut off the water supply to the appliance Gain acce
27. T OF PARTS INDEX 7 0 GENERAL 7 1 PRECAUTIONS 7 2 ACCESS 7 3 PROCEDURES GENERAL 7 4 ELECTRICAL 7 4 44 ON OFF SWITCH 7 4 2 BOILER THERMOSTAT 7 4 8 5 7 4 4 FLOW OVERHEAT FLOW HIGH LIMIT amp FLUE PROTECTION THERMOMSTATS 7 4 5 WATER PRESSURE SWITCH 7 4 6 IGNITION CONTROL BOX 7 4 7 PRESSURE SWITCH 7 4 8 COMBUSTION BLOWER 7 4 9 GAS CONTROL VALVE 7 4 10 GAS LOW PRESSURE SWITCH 7 5 GAS ORIFICE 7 6 SPARK IGNITION FLAME DETECTION ELECTRODE 7 7 BURNER HEAD amp BURNER 7 8 HEAT EXCHANGER 7 9 AIR FILTER 7 10 CONDENSATE TRAP 7 14 PRESSURE GAUGE 7 12 SIGHT GLASS 7 13 HT IGNITION LEAD 7 14 AIR VENT 7 15 AIR ORIFICE Installation amp Servicing Instructions Page 43 WD50 2 1997 Chapter 7 Replacement Of Parts The Keston 50 60 amp 80 Condensing Boilers WEGGIraDrysjG sD I I ONN GCGVIIINFTETRIII I A 7 0 GENERAL The following must always be carried out by a competent qualified person 7 1 PRECAUTIONS i Always switch off the mains electricity supply and disconnect the plug at the isolating switch and socket If a switch only is used then remove the fuse ii Gain access to the appliance Section 7 2 and turn off the gas supply at the appliance service cock 7 2 ACCESS i Remove the front door by releasing the two slotted screws to the front of the top panel The front panel may then be removed by tilting forward and lifting vertically to disengage the two locating studs in the base of the front
28. Using the same methods drill any further holes always covering existing pipework cut and assemble the pipework f From outside complete the two terminations See Section 2 8 Flue System and make good all holes g Support any pipes whose route could be displaced either of its own accord or by accident Any horizontal run over 1m or vertical runs of any length must always be supported h Check all connections for security and re seal any joints using sovent cement where soundness may be in doubt Note Itis equally important to seal the air inlet with solvent cement as the flue outlet pipe joints CONDENSATE DRAINAGE Connect the condensate drainage system to the boiler It is advisable to use a detachable fitting at connection to the boiler to enable easy removal for servicing Fill the condensate trap by pouring water into the boiler flue spigot until water is seen to flow freely from the condensate drainage system Make the final connection of flue pipe to the boiler Details are provided in Chapter 2 Section 2 11 Condensate Drainage Connection 22 mm plastic pipe Installation amp Servicing Instructions Page 20 WD50 2 1997 Chapter 3 Installation The Keston 50 60 amp 80 Condensing Boilers 2 2 kas 3 6 WATER SYSTEM Connect the flow and return pipework to the boiler Ensure a detachable coupling is used at connection to the boiler ie compression fitting to enable heat exchanger removal if required Details
29. WD50 2 1997 The Keston 50 60 amp 80 Condensing Boilers Keston 50 000 60 000 8 80 000 Btu h Model Fan Powered High Efficiency Condensing Gas Boiler Installation And Servicing Instructions Keston 50 GC No 41 930 01 Keston 60 GC No 41 930 02 Keston 80 GC No 41 930 03 No 87AQ306 These instructions must be left either with the user or next to the household gas meter KESTON Boilers 34 West Common Road Hayes Bromley Kent BR2 7BX Tel 44 0208 462 0262 Fax 44 0208 462 4459 4 0087 WD50 2 1997 The Keston 50 60 amp 80 Condensing Boilers CONTENTS Section Description 1 GENERAL INSTRUCTION 1 1 Description 1 2 Boiler Schematic 1 3 Related Documents 1 4 Performance Data 1 5 General Data 2 BOILER LOCATION 2 1 Dimensions amp Minimum Clearances 2 2 Service Connections 2 3 Position 2 4 Electrical 2 5 Boiler Size Selection 2 6 Gas Supply 2 7 Water Systems 2 8 Flue System 2 9 Air Supply 2 10 Compartment Installation 2 11 Condensate Drainage 2 12 Radiant Floor Heating 2 13 Low Water Volume Boiler vs Cast Iron Boiler 2 14 Determine Radiation Needed Room By Room 3 INSTALLATION OF THE BOILER 3 1 Wall Mounting Bracket 3 2 Mounting The Boiler 3 3 Assembly Practice 3 4 Installing Flue And Air Pipes 3 5 Condensate Drainage 3 6 Water System 3 7 Gas Supply 3 8 Electrical Supply 3 9 Exchanging A Boiler 4 COMMISSIONING OF THE BOILER 4 1 Initial Flushing 4 2 Gas Supply 4 3 Electrical Installation
30. Water Central Heating Systems a Disconnect the boiler from the system at the flow and return connections and temporarily link the flow and return pipes on the system b Flush the entire system until clean water is discharged free from dirt flux solder etc The use of a flushing chemical is recommended e g Fernox Supafloc Sludge and scale must be removed from an existing system C Connect the system to the boiler and fill in accordance with Section 2 7 Water Systems At this stage for sealed systems fill to a pressure of about 2 7 bar d Check the complete system for water soundness If leaks need to be rectified using flux and solder the system must be flushed cold again before proceeding e Reduce the pressure to the Initial System Design Pressure for sealed systems if applicable Vent the system 4 2 GAS SUPPLY The complete gas installation up to the boiler service cock must be checked for soundness BS 6891 4 3 ELECTRICAL INSTALLATION Carry out preliminary electrical safety checks i e Earth continuity Polarity Resistance to Earth Short Circuit using a suitable test meter 4 4 LP GAS CONVERSION All Keston condensing boilers are built and shipped as natural gas fired units Field conversion kits are available to convert Keston condensing boilers to use LPG Suitable instructions are supplied with the LPG field conversion kits 4 5 INITIAL FIRING Important Checking the gas pressure to the pre mix burn
31. amp Servicing Instructions Page 27 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers FAULT FINDING FLOW CHART Is amber switch light on Is there 230V between terminals L amp N Is the boiler switched on Faulty Switch Neon Replace Is the fan running yes Is the boiler thermostat closed Is there 230V between control box pins 10 amp 2 Is the air pressure switch stuck in the NO position Is there 230V between pins 6 amp neutral Is there continuity between 6 amp Neutral through motor resistance 18 motor overload tripped Is there wiring continuity amp in line connector to motor Y Continued on sheet 2 Installation amp Servicing Instructions Page Apply Power To Boiler Check External Controls Switch On Boiler Boiler return is too hot Allow to cool OR faulty thermostat Replce Check continuity see section 5 3 Faulty pipe connections to Air Press Switch OR Faulty Air Press Switch Replace Control box faulty Motor Fan faulty Replace Wait for motor to cool Identify amp correct break 28 WD50 2 1997 Continued from sheet 1 Does ignition sequence start yes Is lockout light on Has the Air Press Switch changed over Are tubes and connections to the Air Press Switch sound Is the air press across the Air Press Switch more than 4 in water Is the air
32. at transfer and must be eliminated Installation of air bleed valves at the high spot s in the system will allow for air elimination when filling the system and will allow re venting in a day or so after all air has been driven out of solution Installation of an automatic air vent will ensure that any air even minute amounts which subsequently enters the system will be automatically removed Strainers Debris in the heating system can cause noise if it enters the heat exchanger Fitting of a Y strainer ahead of the circulating pump will trap any debris left in the system and will protect the pump from damage Pump Selection The Keston boilers have low water content heat exchangers with a high resistance to flow when compared with cast iron heat exchanger boilers As a result selection of the correct pump is essential in order to avoid localised boiling within the heat exchanger The selected pump must be capable of maintaining the required flow rate for the boiler against the pressure losses contributed by the boiler and the rest of the system Refer to the pressure loss flow rate Table 2 7 7 to determine the pressure loss from the boilers Add this to the pressure loss caused by the rest of the system and select a pump capable of meeting the flow rate required at the total pressure loss generated by the boiler and the rest of the system The selected pump must comply with BS 1394 Y Strainer will collect any lo
33. boiler but in this case rain etc must be prevented from entering the pipe There must be no troughs in any of the pipework whether it be air inlet or flue outlet If a 45 Figure 2 8 2 Flue amp Air Maximum Length Example mm per meter slope is not possible contact Keston Boilers Technical Department for further guidance Due the low temperature of the flue gases further condensate will form within the flue system Drain Keston Figure 2 8 3 points with suitable traps must Flue Condensate Drain therefore be incorporated within the Point Example flue system at the base of vertical flue sections in excess of 2m These additional condensate drains must be run to discharge as detailed in section 2 11 Such drain points can be formed using standard muPVC fittings Refer to the example in Figure 2 8 3 ToTeniral To Boiler 40mm Tee Fitting 6 in min C7 amp 2 8 4 Terminations It is not advisable to terminate air intake or flue within a car port area Air inlet terminals must be facing upwards and positioned to ensure only fresh air is drawn into the boiler directly from outside the property The flue outlet terminal is designed to face outwards but can if desired be adapted to face in any direction BUT must not be directed in the region of the air inlet The two terminals are subject to the requirements of BS 5440 Pt 1 for clearances from features of the building although some can be decr
34. ction or a high pressure differential between points B amp C in the pre service checks clean the heat exchanger using a suitable stiff plastic bristle brush vacuum out any large particles and flush the heat exchanger with fresh water until the water flowing from the condensate drain is clear When brushing the heat exchanger take care not to damage the condensing plug in the lower half of the heat exchanger Remove the condensate trap Section 7 10 and unscrew the cap Clean by flushing through with clean running water Reassemble in reverse order Check the electrodes mounted on the burner head If the points are damaged or burnt replace them Check that the spark gap measures 4 mm Replace the burner head renewing any gasket as necessary and reconnect the gas air supply and the ignition lead Ensure the flanged gas air supply joint is air tight Turn on the electrical supply to the boiler and allow the boiler to reach operating temperature levels Check for gas leakage around the burner head air gas flexible hose to the burner head and ignitor plug if they have been removed Visually inspect the burner through the glass spy hole at the burner head a small mirror will prove useful Recheck the burner pressure by following the procedure detailed in Section 4 7 Installation amp Servicing Instructions Page 42 WD50 2 1997 Chapter 7 Replacement Of Parts The Keston 50 60 amp 80 Condensing Boilers EN C 7 REPLACEMEN
35. e 52 WD 92 0 1997 KESTON CONDENSING BOILERS IMPORTANT KESTON 50 60 amp 80 INSTALLATION KEY POINTS Read Installation Manual Carefully For open systems ensure that there is at least 8 feet head of water pressure at the top of the boiler DO NOT remove the dust caps from the air and exhaust pipes until ready to connect Ensure that ALL dust particles filings plastic chips etc are removed from the inlet pipe If the installation is a replacement the system must be flushed clean System should be drained hot then refilled then drained again until the water is clean Ensure that there is a proper electrical supply ie 230V fused at 5A Take great care with pipe connections to ensure that no damage is done to the internal pipework Ensure that the 22mm condensate pipe is not exposed to freezing conditions Make sure that the exhaust pipe terminates away from windows or vents and is out of reach Make sure that the air inlet and exhaust pipe outlets are at least 350mm apart Check tightness of all connections in the boiler before firing Ensure that the terminals supplied are fitted to both the exhaust and air inlet pipes Ensure that the air inlet terminal is facing upwards to prevent entry of rain The system must be free from air before firing The pump must always run when the boiler is firing Gravity circuits are not allowed If TRV s are installed on radiators ensure that a bypass
36. e between the boiler flow and the open vent Note that the minimum static head required is 8 ft at the boiler flow pipe If the cold feed vent is not brought to the flow pipe as shown then the pressure loss across the heat exchanger may have to be taken into account when estimating the static pressure Although suitable for open vented systems with combined feed and vent arrangements the Keston is a low water content boiler As such any air entrainement within the system water will produce boiler kettling It is therefore recommended if in any doubt to consider the use of sealed systems where possible Installation amp Servicing Instructions Page 9 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers Expansion Expansion Tank Pipe Minimum 8ft Height Boiler 22mm pipe minimum By pass Bal Valve Figure2 7 1 Open Vented System Diagram 2 7 2 Sealed Systems Sealed systems must be designed in accordance with BS 5449 and BS 7074 Pt1 A typical sealed system is shown in Figure 2 7 2 It must include i A safety valve fitted on the flow adjacent to the boiler It must be non adjustable and preset to 3 bar A drain pipe must be attached at least as big as the valve connection and routed to drain in any area not hazardous nor where it may be subject to freezing ii An expansion vessel complying with BS 4814 and sized in accordance with the
37. e runs back down the flueway and is drained at the base of the flue connection to the heat exchanger The condensate is very slightly acidic about the same acidity as vinegar and should be piped in a plastic pipe It is not harmful to the waste disposal system and may be disposed of as normal waste water The flue gases are piped in a 40mm muPVC pipe to the outside The temperature of the flue gases are usually less than 10 above the temperature of the return water The flue pipe should be terminated outside the building from where they cannot re enter the building or any other adjacent building or cause a nuisance by pluming The heating level may be controlled by room thermostats hot water cylinder thermostats and programmer time clocks RELATED DOCUMENTS The Keston Condensing Boiler must be installed in accordance with the current issue of the Gas Safety Installation and Use Regulations current IEE Wiring Regulations Safety document no 635 The Electricity At Work Regulations 1989 Building Regulations Building Standards Scotland Consolidation and the Bye Laws of the local Water Undertaking In addition due account must be taken to the following Codes Of Practice BS 6891 Gas Supplies BS 6798 Installation Central Heating Boilers BS 5449 2 Installation Pumped Central Heating BS 5546 Installation Domestic Hot Water BS 5440 1 2 Flues BS 5440 2 Air Supply BS 5482 1 Domestic Propane amp Butane Burn
38. eased to the values indicated If either the air inlet or the flue outlet terminate at a height of less than 2m 6ft above ground level the termination must be protected by a suitable guard The K4 terminal guard manufactured by Tower Flue Components Ltd is suitable for this purpose and can be obtained from Keston Boilers The Keston Condensing Boiler as with any condensing boiler will generate a condensate plume from the flue terminal in all weather conditions Consideration must therefore be given to the effect of this plume when selecting a location for the flue terminal Installation amp Servicing Instructions Page 14 WD50 2 1997 2 8 5 2 8 6 Chapter 2 Boiler Connections 65 043 Flue Outlet Ter minal Figure 2 8 1 Ter minals 170 067 The Keston 50 60 amp 80 Condensing Boilers 043 Intake Ter minal 70 is advisable for horizontal flue terminals to place 45 elbow at the end of the flue to direct the condensate plume up and away from the property Dimensions mm Flue Air Terminal Inlet A Below openable window air brick etc 300 50 B Below gutters soil pipes drain pipes 75 75 C Below eaves 300 50 D Below balconies 200 50 E From vertical drain or soil pipes 75 50 F From internal or external corner 600 50 G Above ground or balcony or roof 300 100 H From surface facing a terminal 600 100 From terminal facing a terminal 1
39. ect any gaskets for damage and replace if necessary Set the spark gas as detailed in Section 7 6 Reset the gas rate see Section 4 Commissioning Installation amp Servicing Instructions Page 47 WD50 2 1997 Chapter 7 Replacement Of Parts The Keston 50 60 amp 80 Condensing Boilers lt 7 8 HEAT EXCHANGER Fig 5 7 2 item 43 i ii iii iv v vi vii viii ix X xi xii xiii xiv xvii xviii xix xx Isolate the appliance Section 7 1 Gain access Section 7 2 Shut of the water supply to the appliance Remove the burner head Section 7 7 Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger Remove the boiler thermostat Section 7 4 2 Remove the push on connectors to the water pressure switch flow overheat thermostat flow high limit thermostat and flue protection thermostat taking note of the correct positions Remove the condensate trap Section 7 10 Remove the pressure gauge phial located next to the drain off tap Disconnect the flow and return compression couplings to the flow and return pipes exiting the top of the boiler Remove the push on flue connection to the flue pipe exiting the top of the boiler Remove the complete air filter assembly and flexible air pipe Remove the nut fixing the strap retaining the base of the heat exchanger and pull out the strap by unhooking it from its fixing be
40. el make sure the bracket is completely level and mark the position of the other screw holes d Remove the bracket and drill the holes in the positions marked Plug these holes 285 Screw the bracket to the wall using screws of an appropriate 250 size for the wall type No 12 x 2 inch wood screws normally suffice f Mark the bottom fixing hole and Figure 3 1Wall Mounting Fixing Locations drill for a No 8 x 1 inch wood screw Insert plug 3 2 MOUNTING THE BOILER a Lift and locate the upper rear lip on the boiler to the boiler wall bracket b Move the boiler sideways to centralise the boiler on the bracket Screw in the lower fixing screw 3 3 ASSEMBLY PRACTICE Remove all plastic debris and burrs when installing air intake piping Plastic filings caused by cutting muPVC pipe must not be allowed to be drawn into the filter or combustion air blower Prevent dust entering the air intake when cutting on building sites Blower failure which is determined to be caused by plastic filings or other debris will not be covered by guarantee Installation amp Servicing Instructions Page 18 WD50 2 1997 3 4 Chapter 3 Installation The Keston 50 60 amp 80 Condensing Boilers Combustion air filters are fitted to the Keston condensing boilers as standard This filler must be examined at least once every year and more often in particularly dusty and dirty areas The combustion air filter will prevent pl
41. emperature of the air gas mixture is around 1800 but the Keston achieves combustion at an amazing 1000 thereby reducing the emissions down to an incredible less than 5 p p m The flue system is room sealed and fan powered The ignition is direct spark and fully automatic The boiler housing is not waterproof The boiler should be installed in a position where it will always be dry A small air intake point is incorporated within the appliance cabinet to ensure that the interior of the cabinet is maintained under a slight negative pressure This is a safety feature to ensure no products may leak out of the cabinet into the installation space The boiler is suitable for connection to open vented or sealed systems The system must be pumped central heating or pumped central heating with combined indirect domestic hot water Gravity circuits must not be used The boiler has a primary heat exchanger which through its combustion chamber and corrugated coil transfers the heat produced in the hot gases of combustion process into the circulating water Head characteristics of the boiler coil must be taken into consideration when calculating the pump size The Keston boiler is not a high water content boiler and does not contain the metal mass or water volume of a cast iron or steel boiler This boiler is of low mass and low water content and therefore responds faster when there is a call for heat This feature requires a higher water pum
42. er requires a special procedure outlined below which must be carried out a Purge the gas supply in accordance with BS 6891 b Turn the gas service cock OFF Loosen the screw in the burner pressure test point Figure 5 7 3 item 106A on the gas valve and attach a suitable gauge Installation amp Servicing Instructions Page 23 WD50 0 1996 Chapter 4 Commissioning The Keston 50 60 amp 80 Condensing Boilers ENNIO 3 d Turn on the electrical supply setting any external controls to call for heat e ON OFF switch select ON The amber run light will illuminate on the ON OFF switch the red lockout light will illuminate the blower and pump will start and after about 15 seconds a spark will attempt to light gas at the burner With the gas service cock off the boiler will go to lockout red light illuminated but the blower and pump will continue to run At intervals of approximately 1 minute the boiler will make two further attempts to fire After the final attempt the blower will run for a further 20 seconds before shutting down f Vent the water system Important The Keston heat exchanger consists of a single coil which can trap an air pocket Great care must be taken to ensure that water flow has been established through the heat exchanger and thus ensuring no air pockets remain in the heat exchanger and pipe work Firing the boiler while an air pocket exists in the heat exchanger could da
43. f wait for the fan to reach full speed The pressure difference should be below 11 mbar If not clean heat exchanger Disconnect the gauge from point B Refit the screw Read pressure of point C The maximum pressure should be 3 mbar If the pressure is greater than this check the flue for blockage Turn off the electrical supply to the boiler Remove the pressure gauge tube and refit the screw Open the gas service cock 6 2 Recommended Routine Service a Inspect the air filter located at the top right hand side of the boiler Release the projecting leaf on the filter box and slide out the filter If the filter looks dirty remove the dirt with a vacuum cleaner or by other means If in any doubt renew the filter element b Remove the burner head Section 7 7 and inspect the burner appearance Black markings or other discolourations on the gauze indicate too much gas or a lack of air possibly due to a blocked air filter Any breakages or damage to the burner mesh indicate the burner must be replaced Installation amp Servicing Instructions Page 41 WD50 2 1997 Chapter 6 Servicing The Keston 50 60 amp 80 Condensing Boilers gt C If necessary either due to discolouration or a high pressure differential between points A amp B in the pre service checks clean the burner with a mild household detergent and rinse under a hot running tap If necessary either from visual inspe
44. filter dirty or the air inlet exhaust or condensate pipe blocked Is the Burner blocked Fan faulty change Is the gas flow rate to the boiler correct for the gas type in use ie LPG or Nat Gas yes Is gas supply pressure at gas valve correct Is gas burner pressure per specification Section 4 7 Is gas valve openeing v Continued on sheet 3 Installation amp Servicing Instructions Chapter 5 Fault Finding eee J __ lt The Keston 50 60 amp 80 Condensing Boilers Switch off amp if problem persists replace control box Blocked air filter replace OR Faulty control box replace Correct tube connection Faulty pressure switch replace Replace air filter OR clear blockage Clear blockage Page 29 Check gas supply or turn on gas cock Replace gas orifice Faulty gas valve replace From sheet 3 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers SSS 0 2 Continued from Sheet 2 Continued on sheet 2 Is there 230V at valve Faulty Gas Valve Replace Is there 230V at Gas Low Faulty Gas Low Pressure Press Switch Switch Replace Faulty Control Box Replace Is there a spark present Is the HT voltage present at top of ignito electrode Faulty Conrtrol Box Replace Is the spark gap 4 mm Replace Adjust Spark Plug Electrode Faulty Replace Doe
45. ge 50 WD50 2 1997 Chapter 8 Spare Parts Listings The Keston 50 60 amp 80 Condensing Boilers Item 94 95 99 108 120 GC No Part Denomination Item GC No Part Denomination 375 535Gas Valve Outlet Gasket 107 375 529Flexible Hose Gasket 375 536Gas Valve 375 537Gas Inlet Gasket NO 01 074 Ignition Control Box 110 170 084Air Pressure Switch 379 744 01 075 HT Ignition Cable Installation amp Servicing Instructions Page 51 WD50 2 1997 Chapter 8 Spare Parts Listings The Keston 50 60 amp 80 Condensing Boilers ee SHORT SPARE PARTS LIST FOR THE KESTON Item 22 46 GC No 114 105 375 523 375 524 375 525 375 526 375 527 114 120 114 030 375 530 375 532 375 533 375 534 375 535 375 536 375 537 375 529 E01 074 170 084 379 744 E01 075 CONDENSING BOILER RANGE Part Denomination Air Filter Burner Keston 50 Burner Keston 60 Burner Keston 80 Burner Manifold Gasket Ignitor Gasket Ignitor Sensor Probe Flexible Hose Gasket Boiler Thermostat Flue Thermostat Flow Overheat Thermostat Flow High Limit Thermostat Gas Valve Outlet Gasket Gas Multifunctional Control Valve Gas Valve Inlet Gasket Flexible Hose Gasket Ignition Control Box Air Pressure Switch Keston 80 Air Pressure Switch Keston 50 amp 60 HT Ignition Cable Installation amp Servicing Instructions Pag
46. hind the heat exchanger Remove the allen screw securing the top of the heat exchanger to its mounting bracket Remove the five screws fixing the top of the cabinet Remove the heat exchanger with pipework attached amp the top of the cabinet Separate the top of the cabinet from the combined assembly Remove the flow and flue pipework from the heat exchanger Replacement heat exchangers are supplied with return pipework attached Reassemble Section 7 3 Recommission Section 4 Commissioning 79 AIR FILTER Fig 5 7 4 item 22 i i ii iv v Isolate the appliance Section 7 1 Gain access Section 7 2 Drop the lower section of the air filter housing by pulling forward the securing flap Open the lower section as far as possible and pull out the combined paper filter element with rubber seal Reassemble Section 7 3 NB When fitting the new air filter take care to ensure that the new filter is placed to cover completely the air intake entry into the boiler cabinet 7 10 CONDENSATE TRAP Fig 5 7 2 item 59 i ii iii iv v vi vii viii Isolate the appliance Section 7 1 Gain access Section 7 2 Disconnect the condensate line from the base of the heat exchanger Disconnect the condensate line from the base of the flue assembly Disconnect the condense lines from the projection of the condensate trap from the base of the cabinet Withdraw the condensate trap Mop up any spilled condensate
47. hort Circuit using a suitable test meter Initial Firing Checking The Gas Pressure At The Burner Pressure Test Nipple The gas burner pressure must be checked at the burner pressure test nipple Figure 5 7 3 item 54 Full details of this procedure are given in Section 4 7 Checking The GAS VALVE Gas Pressure The gas pressure setting is factory adjusted to within the required range and should not normally need re adjustment If the reading is incorrect then check such factors as soundness of the air and flue pipe joints pressure sensible joints and the gas inlet pressure 20 mbar required If all joints are sound and the gas inlet pressure is satisfactory i set the gas pressure to the required pressure Burner pressure Adjustment Burner pressure Installation amp Servicing Instructions Page 22 WD50 0 1996 Chapter 4 Commissioning The Keston 50 60 amp 80 Condensing Boilers D eee 4 COMMISSIONING OF THE BOILER Important This condensing boiler contains components which could be damaged or blocked by grease dirt solder etc from the water system The following commissioning procedures must be followed precisely 4 1 INITIAL FLUSHING All waterways within the Keston are either copper or high alloy stainless steel As a result standard water treatment chemicals for conventional central heating boilers are suitable In any event reference must be made to BS 7593 Treatment Of Water In Hot
48. iciently cool without ventilation 2 11 CONDENSATE DRAINAGE Being a condensing boiler the Keston is fitted with a condensate trap at the base of the heat exchanger and flue assembly with facility to connect to a drain point underneath the appliance Use only plastic piping and do not reduce below 22mm internal diameter within the dwelling Condensate should preferably be drained into the house sanitary waste system or alternatively the rainwater system Termination of the pipe must be either at a branch or stack internal to the house or externally at an open gully Alternatively discharge into a purpose made condensate soakaway can be considered Existing or purpose built drains must use suitable corrosion resistant material as condensate is mildly acidic A minimum slope downwards towards the drain of 2 5 45mm fall in 1m is essential Freezing of the termination and pipework must be prevented Any drainage pipes outside the house must be at least 32 mm inside diameter Further guidance is given in the British Gas Publication Guidance Notes for the Installation of Domestic Gas Condensing Boilers 2 12 RADIANT FLOOR HEATING This type of heat distribution creates an exceptionally evenly heated environment and since it is hidden beneath the finished flooring does not interfere with furniture placement The homeowner has complete freedom to decorate without having to contend with any heating equipment visible in the homes interio
49. ing Installations BS 7074 1 Expansion Vessels BS 7593 H Treatment of Water in Hot Water Central Heating Systems BS 7671 Requirements for Electrical Installations Wiring Regulations 16th Edition For Timber Framed Buildings British Gas Publications DM2 Also British Gas Publications Guidance Notes For The Installation Of Domestic Gas Condensing Boilers and Specification For Domestic Wet Central Heating Systems Installation amp Servicing Instructions Page 3 WD50 2 1997 1 General Instruction The Keston 50 60 amp 80 Condensing Boilers 1 4 PERFORMANCE DATA Keston 50 Keston 60 Boiler Input KW 16 6 19 9 27 1 Btu h 56 500 68 300 92 500 Boiler Output To Water KW 14 7 17 5 23 5 80 Flow 609 Return Btu h 50 000 60 000 80 000 Boiler Output To Water KW 15 8 19 2 26 60 C Flow 40 C Return Btu h 54 000 65 000 88 800 Burner Setting Pressure Hot mbar 6 9 10 FACTORY PRESET in w g 2 36 3 54 3 94 Gas Consumption After 10 mins L S 0 43 0 51 0 7 Running Ft Hr 54 43 65 8 89 11 CV of Gas 38 7 MJ m 1038 Btu Ft Maximum Operating Flow 80 00 80 00 80 00 Maximum Head Open Systems M 30 50 30 50 30 50 Ft 100 0 100 0 100 0 Maximum Pressure Sealed Systems Bar 2 70 2 70 2 70 Minimum Head Open Systems M 2 5 2 5 2 5 Ft 8 0 8 0 8 0 Inlet Gas Pressure mbar 20 0 20 0 20 0 in wg 8 0 8
50. is provided in BS 1394 It is advisable to fit a lockshield valve on the cylinder return to enable balancing of flow rate through the cylinder 2 7 4 Boiler By pass Piping Boiler water flows are critical to the operation of the boiler If flow cannot be maintained through the system piping to meet the minimums required by the boiler see paragraph 2 7 g Insufficient water flows through the boiler will cause the boiler to kettle or even produce steam which can damage the heat exchanger and will invalidate the heat exchanger warranty is normally advisable to incorporate a boiler by pass in the system especially if thermostatic radiator valves are used The by pass should be fitted with a lockshield valve to permit balancing of the by pass flow rate The flow return differential should be 10 to 15 The lockshield valve can be adjusted to maintain this condition with the radiators fully heated Installation amp Servicing Instructions Page 11 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers oo gt o ob O o b U 2 7 5 2 7 6 2 7 7 Air Elimination In the initial charge of water to the boiler system and in all subsequent additions of water to the system some air will be dissolved in the water As the water is heated the air is driven out of the solution and will collect in high spots in the system These air bubbles can interfere with pumping and he
51. leakage Replace thermal fuse High water temperature OR faulty thermostat Replace Check water level header tank system pressure OR faulty switch Replace Thermostat tripped reset OR faulty thermostat Replace Check gas supply to boiler OR faulty switch Replace Page 31 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers ee 5 4 FUNCTIONAL FLOW WIRING DIAGRAM L 230v son 2 Fuse 5A Filter ON OFF Switch u Boiler Thermostat Flow Overheat Thermostat Lockout Red Indicator Thermal Fuse Link Flow High Limit Thermostat Low Water Pressure Switch Gas Low Pressure g Flue Overheat Switch Thermostat Air Pressure Switch 5 2 1 RAM 2 22 IGNITION CONTROL 4 2 8 10 6 4 Blower Run Green Indicator AF ON OFF Switch EMC Filter N Installation amp Servicing Instructions 32 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers pecu BM W r o o 5 5 ELECTRICAL WIRING DIAGRAM RAM 2EMC22 B rs ARS AIR PRESSURE IGNITION CONTROL
52. lows and will fully load the boiler Keeping the boiler s temperature high will prevent the boiler from operating at peak efficiencies Systems which maintain boiler temperatures in this way should be avoided If only a portion of the boiler s available output is to be used for radiant floor heating a thermal storage tank will improve the boiler s operation and give adequate control of temperature for the distribution system By heating water to be distributed to the radiant floor zone to the proper temperature in an indirect fired water heater full load conditions will be available to the boiler because the heat exchanger in the tank can be sized to match the boiler s output The tank s thermostat can be set at the optimum operating temperature needed by the distribution system and short cycling of the boiler will be prevented In such insulations it is advisable to calibrate the thermal store s operating thermostat to become the controlling thermostat of the boiler ie the thermal store operating thermostat is always activated to shut off the boiler before the boilers own thermostat is activated An insulated thermal storage tank without the heat exchanger may also be used 2 13 LOW WATER VOLUME BOILER VS CAST IRON BOILER Because of their high water content and mass of metal cast iron and steel boilers are less responsive but somewhat more forgiving of design errors Short cycling of the burner on the temperature limit control is less pronounced
53. lp assure that the boiler is subjected to a sufficient load to avoid short cycling The Keston boilers are capable of temperatures of up to 80 C but the higher the temperature of the return water the lower the efficiency of the system This is true of all boilers though all non condensing boiler must be kept at higher temperatures to avoid condensation in the boiler which destroys such boilers quickly Materials used in the Keston are made to withstand the condensates corrosive nature Installation amp Servicing Instructions Page 17 WD50 2 1997 Chapter 3 Installation The Keston 50 60 amp 80 Condensing Boilers 3 INSTALLATION OF THE BOILER Read Chapter 2 Boiler Location and decide upon the position of the boiler Installation of the boiler is straightforward but consideration must be given to access to allow flue and air pipes to be pushed through walls and ceilings The order in which the components are installed will depend upon particular site conditions but in general it will be easiest and most accurate to install the boiler and then build up the flue outlet and air inlet pipes to the terminal this is the sequence described 3 1 WALL MOUNTING BRACKET All dimensions in mm a Place the bracket on the wall horizontally with the pre drilled holes at the bottom v o fo b Drill through the centre hole of o C O the bracket plug the hole and fix in position Using a spirit lev
54. lution of a 2 cu ft dial or 0 1 cubic m 2 cubic feet of gas through the meter ie one etres if the meter is of the new metric digital type Refer to table 4 8 to determine the input to the boiler and the time required for 2 ft or Installation amp Servicing Instructions Page 25 4 9 WD50 0 1996 Chapter 4 Commissioning The Keston 50 60 amp 80 Condensing Boilers lt 0 1m of natural gas Adjust the gas valve screw clockwise to increase the input speed up the meter or anticlockwise to decrease the input slow down the meter accordingly HANDING OVER TO THE USER It is important to fully explain the following a Procedure to light and turn off the boiler including isolation of the electrical supply if necessary b The function of the lockout feature must be explained If the red light only is illuminated for more than four minutes this means that the boiler has failed to light Turn off the electrical supply and wait 20 seconds Turn ON again and wait i If lockout recurs immediately then the gas supply should be checked as ON otherwise consult a Service Engineer ii If it is not possible to relight the boiler must be isolated and a Service Engineer called in to rectify the fault Advise that a reduction in the water pressure reading on the gauge for sealed systems indicates a leak which should be rectified before further use d Advise that the appliance should be serviced by a competent perso
55. mage it g Note the reading on the pressure gauge caused by the suction of the blower This should be approximately minus 12 mbar for the Keston 80 minus 26 mbar for the Keston 60 and minus 32mbar for the Keston 50 If it is not check the system as follows If the negative pressure exceeds the required figure then it suggests that there is a possible restriction in the air inlet pipework If the negative pressure is less than required figure then it suggests that there is a possible restriction in the flue outlet pipework Note the exact reading h Turn the gas service cock to ON i Turn off the electricity supply wait 10 seconds and turn back on The boiler will again go through its ignition sequence but this time the main burner will light provided all air has been purged from the gas supply to the boiler When the burner is lit and the boiler is operating normally the the green run lamp the upper lamp adjacent to the flame symbol will also be illuminated indicating successful ignition If it does not air is indicated turn off and repeat the procedure If this does not occur the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and at approximately 1 minute intervals the electronic ignition system will make two further attempts to light the burner If the ignition is successful and the boiler is operating normally the green run lamp the upper lamp adjacent to the
56. mbustion Blower Fig 5 7 3 item 80 i ii iii iv v vi vii viii ix Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the cover plate to the electrical connections on the blower motor by removing the four retaining screws Disconnect the wires to the combustion blower taking note of the correct positions Remove the allen screws fixing the air intake pipe flange and the gas air mixture pipe flange to the blower Undo the two nuts securing the combustion blower base plate to the cabinet base and lift out the combustion blower Unscrew the three bolts fixing the base plate and anti vibration mounts to the combustion blower Reassemble Section 7 3 NB When reassembling inspect any gaskets for damage and replace if necessary Reset the gas rate See Section 4 Commissioning 7 4 9 Gas Control Valve Fig 5 7 3 item 95 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the cover concealing the electrical connections on the front of the gas valve Remove the push on connectors exposed taking note of the correct positions Remove the push on connectors to the gas low pressure switch taking note of the correct positions Remove the earth connection to the side of the gas valve Remove the four allen bolts securing the gas inlet flanged connections to the gas control valve Undo the four bolts fixing the base of the gas control valve to the gas outlet block Remove
57. n Blower 114 051 052 053 87 Air Orifice Keston 50 60 80 Nat Gas 114 089 090 091 87D E F Air Orifice Keston 50 60 80 LPG 375 536 95 Gas Valve 114 029 54 Pressure Test Nipple 114 073 105 Low Gas Pressure Switch 114 056 057 058 91A B C Gas Injector Keston 50 60 80 Nat Gas 114 061 062 063 91D E F Gas Injector Keston 50 60 80 LPG Casing Assembly Fig 5 7 4 GC Number Code Description 375 541 1A Cabinet Outer Shell Keston 50 amp 60 375 542 1B Cabinet Outer Shell Keston 80 114 002 20A B C Data Badge Keston 50 60 80 375 543 3 Air Filter Cover 114 105 22 Air Filter 375 545 5 Cabinet Top Cover 375 546 6 Burner Access Cover Plate 114 010 30 Illustrated Wiring Diagram 375 548 12A Front Door Keston 50 amp 60 375 549 12B Front Door Keston 80 Installation amp Servicing Instructions Page 39 WD50 2 1997 Chapter 6 Servicing The Keston 50 60 amp 80 Condensing Boilers G 6 ROUTINE ANNUAL SERVICING To ensure the continued safe and efficient operation of the boiler it is necessary to carry out routine servicing at regular intervals The frequency of the servicing will depend upon the particular operating conditions but it is recommended that an annual service should be carried out by a competent engineer The appliance has an integral air filter mounted at the top right hand side of the boiler to which the air intake pipe is connected This filter should be examined every time the boiler is serviced
58. n at least once a year e Advise on frost precautions f Hand over User Instructions Installation amp Servicing Instructions Page 26 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers eeM 5 FAULT FINDING 5 1 ELECTRICAL CONTROL SEQUENCE When the external controls are calling for heat power will be fed to the boiler connection strip at terminals L Live and N Neutral If the ON OFF switch is also in the ON position the boiler ON lamp amber will be illuminated Provided all temperature thermostats and pressure switches are closed power will be fed to pin 2 on the control box initiating the following sequence 1 The boiler lockout lamp red will be illuminated 2 The fan will start 3 When the fan reaches running speed the Air Pressure switch normally open will close which will start the ignition sequence 4 After a pre purge period of about 15 seconds the gas valve will open to allow gas to mix with the air at the suction side of the fan and the ignition spark will occur at the main burner 5 When the burner ignites the flame is detected by the control box through the combined flame sensor ignitor and the ignition spark is stopped Both the lockout lamp red and the boiler run lamp green the upper lamp adjacent to the flame symbol will be illuminated The boiler is now in its normal run condition 6 The burner will continue to operate until the gas valve interrup
59. ng The Keston 50 60 amp 80 Condensing Boilers 5 7 2 Waterway Condensate amp Flue Assembly SCREW 04 1 00 80 1 IGNITER 04 2 13 00 1 IGNITER GASKE 04 2 00 28 2 PRESS TEST FIT 04 2 28 00 0 SCREW 04 2 00 29 1 MANIFOLD 04 2 00 25 0 SIGHT GLASS 04 2 12 00 1 GASKET 04 2 00 24 1 BURNER 06 2 11 00 0 6 0621100 K8 HIGH VOLTAGI LABEL 04 2 00 58 HEAT EXCHANGE INSULATIO 04 2 10 00 0 K50 6 08 2 10 00 0 9 HEAT EXCHANGE 042 01 001 K50 6 08 2 01 00 1 K8 WATER INLET K50 05 2 00 00 0 K60 06 2 00 00 0 K80 08 2 00 00 0 GASKET SCREW 04 2 00 33 2 04 1 00 79 1 SECTION 3 EXHAUST 4 2 18 00 0 K50 60 08 2 18 00 0 90 TEST TWO 04 2 00 49 04 2 00 67 f 28 ELBOW 04 2 00 61 0 FLUE OVERRERI 28 WATER FLO THERMOS TA AUTO AR VEN PIPE 04 2 19 00 04 2 20 00 1 04 2 00 66 WATER RETURI 04 2 17 00 04 2 00 53 0 04 2 00 43 1 GASKET i e DRAIN VALVE DEO SCREW 04 1 00 41 0 CONDENSATE TRAP HOS 04 2 00 34 SEEGER RIN SCREW 04 1 00 41 3 28 WATER RETURI PIPE 4 2 00 65 0 K50 6 08 2 00 65 0 KB
60. nsure connection is made such that if the cable slips in its anchorage the current carrying conductors become taut before the earthing conductor 3 9 EXCHANGING A BOILER Before removing an existing boiler add Fernox Supafloc or equivalent cleaning agent in accordance with the manufacturers instructions Open all radiator valves and fire the boiler When the system is fully heated shut off the gas supply and drain down the central heating system Installation amp Servicing Instructions Page 21 WD50 2 1997 Chapter 3 Installation The Keston 50 60 amp 80 Condensing Boilers Important The Keston condensing boiler contains components which could be damaged or blocked by grease dirt or solder etc It is essential that sludge or scale is removed from an existing system Connect the new boiler as instructed in this manual and fit in accordance with Sections 3 1 to 3 8 For sealed systems fill to a pressure of about 2 7 bar Check the complete system for water soundness If leaks need to be rectified using flux or solder the system must be flushed cold again before proceeding Reduce the pressure to the Initial System Design Pressure for sealed systems if applicable Vent the system Gas Supply The complete gas installation up to the boiler service cock must be checked for soundness BS 6891 Electrical Installation Carry out preliminary electrical safety checks i e Earth continuity Polarity Resistance to Earth S
61. ose debris in the piping PressureLass m Figure 2 7 6 Strainers 45 4 4 s s eee ee pu nens K ston 50 K ston 60 Water Flow L min Figure 2 7 7 Pressure Loss Graph Installation amp Servicing Instructions Page 12 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers It is important to note that the minimum flow rate must be maintained whenever the boiler is firing Systems using zone valves must be specifically designed to only fire the boiler when the pump is running and the minimum flow rate can be achieved The Wilo Salmson Gold Star pump or the Grundfoss 15 60 pump is normally suitable for use with the Keston condensing boiler range However in all cases due consideration must be given to the resistance to flow offered by the rest of the system when making a final pump selection This is particularly important when using small bore underfloor heating pipework Boiler Model Keston 50 Keston 60 Keston 80 Min Flow Rate 4 2 GPM 5 0 GPM 6 7 GPM Required 19 1 litres min 22 7 litres min 30 5 litres min Pressure Loss 3 2 ft 4 3 ft 9 0 ft Through 0 97m 1 3m 2 75 Boiler 9 7 kPa 13 kPa 27 5 kPa
62. ping rate through the boiler otherwise localised boiling will occur within the boiler Allow a pressure drop through the boiler of 3 2 ft head and a water flow of 4 2 gallons 19 litres per minute for the Keston 50 4 3 ft head and 5 gallons 23 litres per minute for the Keston 60 and 9 ft head and 6 7 gallons 30 5 litres per minute for the Keston 80 The boiler selected must be sized relative to the total calculated heat loss of the building The boiler rated output should not be greater than the total required to make up the calculated heat loss plus the heat required to provide domestic hot water If there are special conditions such as excessive domestic hot water usage consult the manufacturer BOILER SCHEMATIC Air is drawn into the boiler through a 40mm BS5255 muPVC pipe The air flow is proved by a differential pressure across the air control orifice Gas is mixed with combustion air at the inlet to the fan The gas flow is regulated by an orifice located in the housing downstream of the gas valve Installation amp Servicing Instructions Page 1 WD50 2 1997 Ta 1 General Instruction The Keston 50 60 amp 80 Condensing Boilers Figure 12 Boiler Schematic 4 LEGEND 1 Heating Return Ignition Control Box 2 Water Return Thermostat Gas Low Pres
63. r The low operating temperatures of this type of system lead to very good operating efficiencies In fact under floor heating can produce in excess of 95 operating efficiency from a Keston condensing boiler Water temperatures in radiant floor heating systems must be kept relatively low generally under 48 C so that surfaces do not become uncomfortably warm to the touch If radiant heating is only one application for a multi zone system which also requires higher delivery water temperatures for other zones i e water heating skirting heaters etc then the radiant floor zone temperature will need to be controlled separately from the boiler If radiant floor heating is the only application of the boiler the boilers temperature limits can be lowered accordingly by introducing an external thermostat control mounted on the return pipework into the boiler This thermostat can then be used to interrupt power Installation amp Servicing Instructions Page 16 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers 6 supply to the boiler when the required temperature is reached Mixing valves are also available which will mix return water from the system with boiler output water to dilute the temperature of water transmitted to the distribution system Mixing valves may create problems with low flow and high temperatures through the boiler unless care is taken to design a system which will provide proper f
64. r room thermostats etc must act by switching the 230V supply to the boiler 2 System designs which allow the boiler to fire when there is no pumped circulation must NOT be used 3 A programmer may be used with zone valves to give independent control of central heating and hot water BOILER SIZE SELECTION The size of the boiler to be used is determined by the total calculated heat loss of the building Match the calculated heat loss with the boilers rated output f a boiler is installed with an output rating greatly exceeding the total capacity of the distribution system the efficiency of the boiler will be reduced If the boiler is to be used to heat domestic hot water no additional capacity is normally needed for the average residential installation since there is usually some excess capacity in the boiler as water heating is an intermittent load GAS SUPPLY A gas meter should be connected to the service pipe by the local gas supplier or their contractor An existing meter should be checked preferably by the gas region to ensure that the meter is adequate to deal with the rate of gas supply required Installation pipes should be fitted in accordance with BS 6891 Minimum Maximum Natural Gas Pressure Natural gas pressure before the gas valve must be maintained at 20 mbar 8 in w g while the boiler is running Gas pressures above or below this level will lead to problems associated with the gas valve s internal pressure regulator
65. requirements of BS 5449 and BS 7074 Pt 1 The vessel must be positioned on the inlet to the pump iii A filling point in accordance with local water authority requirements iv A method of system make up automatic or manual in accordance with local water authority requirements v There must be no permanent connection of mains water to the boiler system vi The installation must be designed to work with flow temperatures of up to 110 All components of the system including the heat exchanger of the indirect cylinder must be suitable for a working pressure of 3 bar and a temperature of 110 Care should be taken in making all connections that the risk of leakage is minimised Installation amp Servicing Instructions Page 10 WD50 2 1997 Chapter 2 Boiler Connections The Keston 50 60 amp 80 Condensing Boilers Make up vessel Max capacity of Air Vent 3 It Spt Non Return pd nt bib tap a Auto Air Vent Boiler Keston Strainer Hosepipe A disconnected gt after filing lt _ Drain Cock k aoe Double Check SS Hose Valve Connector Test Cock Figure 2 7 2 Sealed System Diagram 2 7 3 Hot Water System if applicable The hot water storage vessel must be of the indirect type certain direct cylinders can be used provided they are suitably adapted by fitting an immersion calorifier DIRECT CYLINDERS MUST NOT BE USED Further guidance
66. s the burner ignite Recheck gas output pressure Check HT lead is securely fixed Clean or replace burner Does flame stop after 5 10 seconds Is boiler earthed correctly Earth Boiler Are live and neutral supply lines crossed at terminals L amp Correct Wiring N Faulty Control Box Replace Installation amp Servicing Instructions Page 30 WD50 2 1997 Chapter 5 Fault Finding The Keston 50 60 amp 80 Condensing Boilers 5 3 CONTINUITY CHECKING Is there 230V at terminal L Is there 230V at the ON OFF Switch both terminals Is there 230V at the boiler thermostat both terminals Is there 230V at the flow overheat thermostat both terminals Is there 230V at the thermal fuse link both terminals Is there 230V at the flow high limit thermostat both terminals Is there 230V at the water press switch both terminals Is there 230V at the flue protection thermostat both terminals Is there 230V at the gas low press switch both terminals Installation amp Servicing Instructions To check continuity connect one probe to a neutral and use the other probe to check for 230V Check external controls Faulty switch Replace Boiler is up to temperature Allow to cool OR pump not running OR faulty thermostat Replace Thermostat tripped reset OR faulty thermostat Replace High cabinet temperature check all joints for products
67. ss Section 7 2 Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger Remove the push on connectors from the water pressure switch taking note of the correct positions Unscrew the pressure switch Reassemble Section 7 3 NB Use a little jointing compound or PTFE tape on the thread Refill the system See Section 4 Commissioning 7 4 6 Ignition Control Box Fig 5 7 1 item 108 i ii iii iv v vi Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the HT ignition lead Pull off the multi pin connector away from the box Unscrew the two screws securing the control box to the casing and remove the box Reassemble Section 7 3 Installation amp Servicing Instructions Page 45 WD50 2 1997 Chapter 7 Replacement Of Parts The Keston 50 60 amp 80 Condensing Boilers 7 4 7 Pressure Switch Fig 5 7 1 item 110 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the air pressure switch taking note of the correct positions Disconnect the union to one plastic tube connection and pull off the second plastic tube from the air pressure switch Unscrew the two screws mounting the air pressure switch body to the boiler casing Reassemble Section 7 3 NB Ensure the yellow green earth connection tag is securely fixed behind the lower mounting screw 7 4 8 Co
68. sure Switch 3 Downstream Pressture Test Nipple Gas Multifunctional Control 4 Flame Ignition Sensing Probe Gas Inlet Flexible Connector 5 Burner T Air Pressure Switch 6 Automatic Air Vent B Combustion Blower 7 High Limit Thermostat D Condensate 8 Heating Flow 20 Flue Overheat Thermostat 9 Flue Exhaust 21 Heat Exchanger D Air Gas Flexible Connector 22 Flow Overheat Thermostat T Air Filter 23 Water Low Pressure Switch D Air Inlet Flexible Connector 24 Combustion Test Point Installation amp Servicing Instructions Page 2 WD50 2 1997 vac 1 General Instruction The Keston 50 60 amp 80 Condensing Boilers 1 3 The gas and air are thoroughly mixed in the blower and fed into the burner located at the top end of the heat exchanger module The gas and air mixture is ignited by a direct spark ignition control system and burns with a blue flame just off the surface of the burner As the hot products of combustion pass downwards they are cooled exchanging heat with the circulating water which enters the heat exchanger coil at the bottom of the heat exchanger When the return water temperature is below 540C part of the water vapour in the combustion products will condense inside the heat exchanger thus increasing the boiler efficiency This condensate falls to the bottom of the heat exchanger where it is separated from the flue gases and exits from the boiler through the condensate drain Any condensate formed in the flu
69. t nipple The gas setting is factory adjusted to within the required range and should not normally need re adjustment unless the unit has also been converted to LPG as part of the installation If the reading is incorrect then check such factors as soundness of the air and flue pipe joints and the gas inlet pressure 20 mbar required If all joints are sound and the gas inlet pressure is satisfactory remove the brass dust cap covering the burner pressure adjustment screw on the gas valve See fig 4 7 Set the gas pressure to the required value as stated in table 1 4 by turning the exposed burner pressure adjustment screw clockwise will increase burner pressure anti clockwise will decrease burner pressure Replace the brass dust cap to 4 8 TIMING THE GAS METER NATURAL cover the burner pressure adjustment screw GAS Model Btu h Input Required Seconds For 2 ft Seconds For 0 1 m Of Natural Gas Of Natural Gas Keston 50 54 400 133 8 236 2 Keston 60 63 018 115 5 203 9 Keston 80 84 300 86 3 152 36 NB 1011 btu h per ft Table 4 8 Meter Timings After the boiler has been started and wit h no other appliances using gas time the gas meter to be certain that the unit is running at the proper gas input Determine the cubic feet of gas passing through the meter and determine the input in Btu per hour Input must be within plus or minus 5 of the rated input Time in seconds the time taken to pass revo
70. tion 2 7 2 Sealed Systems are included in the system Any system must be thoroughly flushed clean of grease dirt and debris prior to connection with the boiler A trap may be installed in the flow line to collect any solder or other debris from the installation All water systems must be constructed to comply with requirements of the Local Water Authority Only fully pumped systems can be used gravity systems are strictly not suitable Always use a system complying with the requirements of BS 5449 and BS 6798 The system must be so arranged that there shall always be a minimum flow of 4 2 gpm 19 litres min Keston 50 5 23 litres min Keston 60 or 6 7 30 5 litres min Keston 80 when the boiler is firing This be via a specially installed by pass arrangement Copper tubing to BS 2871 Part 1 is recommended Jointing should be either with capillary or compression fittings Pipes should have a gradient to ensure air is passed easily to vent points and water flows readily to drain points Draining taps must be located in accessible positions which permit the draining of the boiler and hot water storage vessel Draining taps should be at least 15 mm in nominal size and be in accordance with BS 2879 AIR VENT POINTS These must be fitted at all high points where air may collect Open Vented Systems A typical system is shown in Figure 2 7 1 which includes a combined feed and vent Note there must be no valv
71. ts T otherwise D will have to be increased by clearance from T See Section 3 4 3 Examples 3 4 8 Examples a Wall Depth L 750 mm Unsocketted pipe du 43 mm Diameter hole D 43 59 1599 X10 43 7 5 50 5 mm Installation amp Servicing Instructions Page 19 WD50 2 1997 Chapter 3 Installation The Keston 50 60 amp 80 Condensing Boilers EE AA NET b Wall depth L 2 3 Socketed Pipe ds 50 Diameter Hole D 50 2 3 10 50 23 73 mm C Measure cut and check the air and flue pipes to pass to the exit from the wall s or ceiling Always thoroughly deburr all pipes and most important remove shavings from within the pipe d Assemble using adhesive the pipework from the boiler connections to the exit from the first wall ceiling remount the boiler if removed When pushing pipe through walls ensure grit and dust is not allowed to enter the pipe Ensure pipes are fully engaged into sockets Connect the condensate drainage system and fill the condensate trap by pouring water down the boiler flue spigot See Section 3 5 Condensate Drainage Make the final connection of flue and air pipe to the boiler using push on or plastic compression couplings Ensure that the connectors F A are set vertically otherwise leakage of condensate may occur which will corrode the casing Do not use adhesive on the push on end of the connecting couplings Fully Engaged Adhesive e
72. ts the gas supply The gas valve will be closed by the control box if power is interrupted to the boiler by any external control or the boiler thermostat If an interruption to the gas supply causes loss of the flame the control box with pause for approximately 10 seconds and then attempt to re ignite the unit If this attempt fails ie due to lack of gas supply the boiler will make two further attempts to ignite at intervals of approximately 1 minute and will then go into a lockout state red lamp illuminated only Once gas supply has been resumed the boiler can be reset by turning the boiler off and then on again via the on off switch on the boiler control panel 7 The boiler can also be shut down by any of the flow limit flow overheat and the flue overheat thermostats gas low pressure switch and by the low water pressure Switch In such an event the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and only the red lockout lamp will be illuminated Any failure of the boiler to sequence in the above manner should be investigated using the following trouble shooting flow diagram Before attempting any electrical fault finding always carry out preliminary electrical system checks On completion of any service fault finding task which has required the breaking and remaking of electrical connections the checks earth continuity polarity short circuit resistance to earth must be repeated Installation
73. ugging of the burner caused by dirt being trapped in the burner s outer mesh The filter element supplied with the boiler is obtainable from Keston Boilers or its distributors INSTALLING FLUE AND AIR PIPES Remember the flue pipe must slope downwards back towards the boiler and this is best achieved using 92 5 bends a From the two connections on the boiler mark the positions of the two holes for the flue and air pipes on the wall s or ceiling To allow access to drill the holes it may be necessary to temporarily remove the boiler If the boiler stays put then it is imperative that the front panel and top access plate are replaced and the two plastic pipes capped off whilst drilling Under no circumstances must debris from the wall or cut pipes be allowed to enter the appliance or the plastic pipework b Drill the two holes in the wall ceiling preferably using a core drill 3 4 1 Diameter of holes i Allowance must be made for Socketed lengths if these are to be passed through the holes du du unsocketted D diameter 43mm T ds socketed diameter 50 mm K L gt ii For horizontal runs of flue pipe the holes must either be oversized or cut at a 5 slope the latter may be difficult on Ba long holes Flue Pipe 3 4 2 Oversizing For every 1m length of run L the minimum diameter of the horizontal hole D must be du 10 mm or ds 10 mm respectively assuming the pipe touches the wall at poin

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