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1. Thermostat circuit A WARNING continued from page 12 120 volt potential exposure Use caution making voltage checks to avoid personal injury P2 Check AC source to 5 determine why there is no O O fete ewer CONTROL P a x N power P3 bets S UT LECTRONIC OOo ata CONTROLS Replace i POWER ignition module P5 T7 DOT INDICATOR PURGE LIGHTS IGNITOR see page 34 dl PRIMARY VALVE P1 DO 4s E WE ave FOR OPERATING SEQUENCE TROUBLESHOOTING SEE INSTALLATION 4 20V AC g P6 AND OPERATING INSTRUCTION MANUAL y 2 P7 DO 1 ANSI Z21 20 AUTOMATIC IGNITION SYSTEMS Refer to ignition module Refer to ignition module y re We OSM 30 00 illustration Is there 120VAC illustration Is there 120VAC fiat O TYSTEM WILL AUTOMATICALLY RETRY AFTER 1 HOURS O between P1 1 and P1 3 between P7 3 and P7 1 y ICNTOROZ A WARNING THIS DEVICE CAN MALFUNCTION IF_IT GETS e VALVEO E EXPLOSION HAZARD CAN CAUSE WAS BEEN WED REPLACE M T FLAMEO2 J QO Refer to ignition module illustration Is there N Replace transformer IGNITION MODULE 22 27 VAC between P2 1 and P2 2 Y y see page 35 E Red Wires Temper
2. Installation Site Name amp Address Installation Site Contact Name Phone Number U H E Service Manual Page 45 O a Parts List X J 25A 27A a K P Na 21 EXPLODED VIEW oo 24 18 EXHAUST SERVICE AREA DETAIL ASSEMBLED 1 Combustion Surround Assy 2 Burner Assy specify model 3 2 Pass Top Collector Cover 4 Screw 10 16 x 3 4 5 Vent Termination Elbow 6 Thermostat Sensor Probe 7 Baffle 4 Flue specify model 8a_ Anode Rod Assy 8b Powered Anode for UHE100T399 9 Baffle 2 Flue 10 Wire Harness Service Panel 11 Plastisert Nipple 1 4 NPT 12 Plug 13 Nipple 14 T amp P Relief Valve 15 Exhaust Pipe PVC w Hose Barb except UHE100T399 16 Condensate Trap Elbow specify model 17 Silicone Hose 18 Outer Door Service Panel specify model 19 Vent Pipe Support Bracket except UHE100T399 20 NSF Escutcheon 21 Exhaust Pressure Switch 22 Nuts 23 Collector Temperature Limit Switch 24 Screw 6 32x 3 8 25 Cleanout Access Cover 26 Cleanout Gasket 27 Screw 5 16 18 x HH Grade 5 28 Cleanout Cover 29 Cold Water Inlet Hydrojet Assy 30 No Handle Brass Drain Valve 31 Concentric Vent System optional 32 ASSE Approved Mixing Valve optional Customer must specify complete model number and s
3. SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement Thermostat Potentiometer Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Step 11 Position main power switch to OFF WARNING 120 volt potential exposure Isolate the Disconnect unplug water heater from 120 volt power source appliance and reconfirm power is disconnected using a multi meter Un latch and remove top surround cover from top of heater Temperature Adjusting Knob Loosen set screw with small blade Loosen set screw of adjusting oder knob small blade screw driver and remove adjusting knob from potentiometer see photos at right LN Remove retaining nut Remove retaining nut 72 wrench and washer from potentiometer see photos at right From inside of surround area remove potentiometer with gasket from side of surround Notice how indexing tab on potentiometer assembles into locating hole of surround see photos below f Indexing Tab Locating Hole es Potentiometer gt Wire Leads s eo S PA l e a No gt ae y 7 r Disconnect potentiometer wire leads see photo at right Install new potentiometer with gasket into side of surround Be sure to assemble with indexing tab inserted into locating hole on side of surround see ph
4. S es Check Exhaust Tube Pressure O With monometer take a N a a Y reading at the exhaust exaust Vonung tube pressure tap location N system blocked or Clear obstruction E obstructed Also Determine cause Is value negative or e check condensate and correct slightly postitive elbow and drain see illustration below _ o e Y F Reconfigure vent Is vent Y total evstemaio be length compliant with N hada liani with vent tables in the p vent tables see instruction p Specifications No E a Replace blocked vent switch see page 29 S Pi Y O N With ohmmeter check pressure switch for be closed continuity Contacts should Is pressure in exhaust tube near 2 7 w c or more If so correct blockage above If exhaust pressure is low 0 40 or less replace y ii Pressure switch O K pressure switch Exhaust Tube pressure tap location Exhaust tube q at bottom of heater U H E Service Manual Page 29 O N Service Procedure UHE VI Exhaust Pressure Switch Testing and Replacement a J Exhaust Pressure Switch Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Position main power switch to OFF position
5. Continued from appliance and reconfirm power is previous page A i disconnected using a multi meter Refer to ignition module illustration below R blav P2 is there 24VAC between P3 2 and P3 5 blue and N ea brown wires during the flame establishing period miare monu G cove SA Note Valve LED must be lit during creci s66 page 34 P3 ioe 8 E 2 UT ne AA mr CONTROLS Y 1013 SERIES i CONTROL BLOWER PURGE P5 TT DDG a pe ay IGNITOR PRIMARY E E ex 7 m FLAM Replace Rectifier ha rn ess and or P1 E re 1 E FOR OPERATING SEQUENCE TROUBLESHOOTING SEE INSTALLATION Can you hear or feel N 20V AC IN g P6 AND OPERATING INSTRUCTION MANUAL gas valve energize gas valve P7 S DZ 1 i ANSI Z21 20 AUTOMATIC IGNITION SYSTEMS J see page 24 K Y m MNNG oe E REP ARTEEN o 2 Turn VENTURI set screw clockwise until its N z bottomed out Turn screw counter clockwise 6 2 turns from bottom see illustration below Note IGNITION MODULE UHE100T399 models do not have a venturi screw The gas regulator setting should be 1 1 Y turns C out from bottom J Clear obstruction F Inspect burner tube see page a N Y Does burner light Check for obstruction smoothly without at inlet of gas valve evidence of coughing N Is inlet free of or huffing obstruction Venturi E adjustment Y Inlet gas pressure tap Y Call for technical supp
6. WARNING 120 volt potential exposure Use caution making voltage checks to avoid personal injury O N Is there continuity Locate harness Through GREY y connection Lead wires of heater side see photo at right harness see photo at right 8 Call technical T Depress reset a y button on high Does ln limit switch ls y Replace vent there continuity gt gt safety switch function A across high limit see page 37 switch System OK see photo below q a J Control side Heater side harness harness y Reset heater observe heating cycle Does Is temp over 350 F switch open OS DO NOT OPERATE 7 iad 8 N HEATER 4 5 Does switch open prior 3 pe System over heating El ae 7 to 350 F A gt immediately contact P C technical support a k Replace vent safety switch Reset button see page 37 de a A WARNING Make sure exhaust collector compartment is not overheating 350 F before resetting vent safety switch If there is evidence the collector compartment is overheating CALL TECHNICAL SUPPORT U H E Service Manual Page 37 7 Vent Safety Switch Testing and Replacement Service Procedure UHE XI Vent Safety Switch Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 St
7. Step 7 Step 8 Step 9 Step 10 Positi i itch to OFF A AARDIG osition main power SWITCN TO j 120 volt potential exposure Isolate the Disconnect Unplug water heater appliance and reconfirm power is from 120 Volt power source disconnected using a multi meter Un latch amp remove surround cover from top of water heater Locate Ignition module on control panel inside surround area see photo below Ignition Module located on control panel Note Replacement hot surface ignition module works on all UHE models prior to and later than CF serial numbers Direct spark ignition models use a different control board detailed in following section Carefully disconnect all wire harness connection to ignition module Connection are non interchangeable to insure proper reinstallation Remove the 3 screws Phillips screw driver holding the ignition module in place and remove ignition module from control panel Install new ignition module and secure in place with screws from step 6 Carefully reconnect all wire harness connection to ignition module Connection are non interchangeable to insure proper reinstallation Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Replace surround cover on top of water heate
8. This turbulence causes a thorough mixing of gas and air for optimum combustion The combustion gases then travel through a three pass flue system keeping the gases moving at a high velocity The combination of high turbulence and velocity results in an optimum transfer of heat from the flue gases into the water Burner operation is controlled using an electronic ignition module The module monitors the status of the electronic thermostat vent temperature limit switch vent system pressure switches and a flame sensor to control output voltage to blower motor hot surface igniter and gas valve The module contains programming which determines the sequence of operation and timings for purge periods trial for ignition flame sensing and lockout The module will also provide diagnostic information to help in determining the cause of system lockouts The contents in this manual are detailed informational tools to assist in the proper diagnosis of the Ultra High Efficiency Water Heater operational faults Please read this service manual completely and provide as much information regarding the Ultra High Efficiency Water Heater operation and installation specific concerns Page 4 LAARS Heating Systems C N How to Use This Manual Ns P It is intended for this manual to be used by qualified service personal for the primary purpose of troubleshooting analysis and repair of the LAARS heating system Ultra High Efficiency Water Heater
9. Loosen adhesive backed rubber escutcheon from service panel access cover and slide escutcheon back along exhaust pipe to allow for removal of cover Rubber escutcheon Remove screws from service panel access cover nut driver and remove cover from heater see photos at right Disconnect silicone tubing and wire leads from pressure switch see photos at right Remove pressure switch mounting screws 5 16 wrench and remove pressure switch Pressure switch k l mounting screw Assemble new pressure switch to heater using 5 16 hex head screws from step 5 T r Wire leads EF fo j SE ER C AS ae is Reconnect wire leads Note wire leads are interchangeable with either terminal E o pS l ie we Silicone tubing at Reconnect silicone tubing to pressure switch as follows a Exhaust pipe tubing connects to single tap located on switch Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction anc une label or the lighting instructions located in the installation pressure tap location and operating instruction manual Reinstall service panel access cover and rubber escutcheon Page 30 LAARS Heating Systems A Service Procedure UHE VII _ Hot Surface Igniter Testing and Replacement Hot surface Igniter Testing Procedure WA
10. Understanding the sequence of operation section of this manual will contribute greatly to troubleshooting this product An Installation Check List is shown on page 43 Compare the installation against the installation check list to confirm all requirements are met An UHE Service Report is shown on page 44 Completing this form will assist in the troubleshooting efforts Should you need to call for technical support Please provide the information shown on this form to the support technician to insure accurate troubleshooting Troubleshooting begins with System Observation to determine failure mode as indicated by the LED status of the ignition module Troubleshooting continues with Failure Modes and Probable cause listed on page 10 directing the service provider to a series of test procedures to determine root cause of failure Component replacement procedures directly follow the test procedures for a given component In some difficult to diagnose conditions it may be necessary to isolate the heater from the vent system to determine root cause Contact Technical support immediately if diagnosis is not determined using the methods described in this service manual Tools Required for Service Manometer Two types available a liquid U tube type or a digital magna helic type This device is used to measure gas and or air pressures and vacuum Multi Meter A digital type is strongly recommended This device is u
11. WARNING Heater components and stored water may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury Step 1 Turn off water supply and drain water heater Step 2 Disassemble water heater per Disassembly Procedure for Access to Andoes amp Flue Baffles Step 3 Locate and remove anode rods from heater 1 1 16 hex socket Step 4 Visually inspect anode rod Anode rod should show signs of depletion this is normal If the depletion is Y of the original diameter approximately 3 4 diameter replacement is recommended If any of the steel core of the anode is exposed replacement is recommended Step 5 Upon completion of inspection or subsequent replacement apply thread sealing tape or other thread compound to threads of anode and reinstall into heater Restore water supply and check for and repair any leaks found Step 6 Reinstall collector cover per Collector Cover Installation Procedure Step 7 Reinstall collector insulation and control panel reconnect control panel wire harnesses Step 8 Restore 120 volts to water heater and verify proper heater operation following the instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Step 9 Replace surround cover on top of water heater Page 40 LAARS Heating Systems r Service Procedure UHE XII _Anode Flue Baffle Insp
12. added together must not exceed Maximum u i 7 gt Maximum Vent Length Combined Length Shown below Shown below Maximum Combined Length feet Maximum Vent Length feet Model Number 3 q Model Number 3 q UHE60T125 UHE100T150 120 170 UHE60T125 UHE100T150 120 170 UHE60T150 UHE100T199 100 150 UHE60T150 UHE100T199 100 150 UHE60T199 80 130 UHE60T199 80 130 UHE100T250 80 130 UHE100T250 80 130 UHE100T300 60 110 UHE100T300 60 110 UHE100T399 50 100 UHE100T399 50 100 Unbalanced Direct Vent Systems Air intake CAN NOT exceed exhaust by more than 30 feet Notes 1 Multiply the total number of 90 elbows intake and exhaust by 5 feet Do not include the termination fittings or 3 condensate elbow 2 Multiply the total number of 45 elbows intake and exhaust by 2 feet 3 Add this to the total length of straight pipe intake and exhaust 4 The sum total of all elbows and straight pipe intake and exhaust must not exceed maximum lengths from tables above Example UHE100T199 A 3 Balanced Direct vent system has 30 feet of straight exhaust pipe and 30 feet of straight intake pipe It has 3 90 elbows in the exhaust and 3 90 elbows in the intake It has 1 45 elbow in the exhaust and 1 45 elbow in the intake Therefore 6 90 elbows x 5 feet 30 feet 2 45 elbows x 2 feet 5 feet 60 feet of straight pipe 30 feet 5 feet 95 feet System is wi
13. down system will post purge and wait for switch to close before attempting re ignition If the blocked vent pressure switch opens indicating a blocked exhaust vent condition the gas valve is shut down blower shuts down for 30 seconds and is re energized and system attempts re ignition if the pressure switch is closed Blower operates for 5 minutes to wait for pressure switch to close then shuts off with purge light flashing lock out Will restart in 1 hour to attempt to close the switch and restart ignition sequence Flame sensor circuit If flame is lost gas valve is shut down system will post purge and system attempts re ignition Thermostat satisfied Burner off Blower post purge 15 seconds U H E Service Manual Page 9 fr Sequence of Operation a Se yr Lockout Conditions Lockout conditions The system will go into lock out mode for the following reasons Blocked vent pressure swi
14. elbows or straight exhaust terminal coupling recommended Gas Requirements Gas piping sized adequately 3 4 or larger to heater or 1 or larger for UHE100T399 models Install a properly sized regulator if unknown assure an adequate volume of gas is available 7 W C is required when the unit is running Gas pressure must stay below 14 W C static pressure Pressure drops between static pressure and operating flow should be less than 3 W C Condensate Requirements Condensate line needs to slope to a drain at a minimum of 1 4 per foot Make sure the condensate line does not have the potential to freeze If using more than one heater and using a common condensate line make sure the condensate line is properly sized Service Mechanical Room Provide adequate space for servicing heater Leave room to get to the top and bottom pressure switches as well as enough overhead room to remove the anode rods for servicing 18 min Vent tables Balanced Direct Vent Systems Power Vented Systems PVC CPVC PVC CPVC Total length of intake piping and exhaust piping Total length of exhaust piping must not exceed added together must not exceed Maximum Maximum Vent Length Combined Length Shown below Shown below Maximum Combined Length feet Maximum Vent Length feet Model Number 3 q Model Number 3 q UHE60T125 UHE100T150 120 170 UHE60T125 UHE100T150
15. see shaded area F 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 0 26109 19906 15314 11884 9299 1333 9827 4663 3 58 3048 2488 2043 1688 1402 1170 982 828 NOTE Sensor resistance increases as the temperature falls In Degrees F 1 2 3 5 6 7 8 9 25400 24712 24045 22771 22163 21573 21000 20445 19383 18876 18383 17440 16990 16553 16128 15715 14925 14548 14180 13477 13140 12812 12494 12185 11592 11308 11032 10502 10248 10000 9760 9526 9078 8862 8653 8250 8057 7869 7685 7507 7165 7000 6839 6683 6531 6383 6238 6098 5961 5697 5570 5446 5326 5208 5094 4982 4873 4767 4562 4464 4368 4274 4183 4094 4006 3922 3839 3679 3602 3527 3453 3382 3312 3244 3177 3112 2986 2925 2866 2808 2752 2697 2643 2590 2538 2439 2391 2344 2298 2253 2209 2166 2124 2083 2004 1966 1928 1891 1856 1820 1786 1753 1720 1656 1625 1595 1566 1537 1509 1481 1454 1427 1376 1351 1327 1303 1280 1257 1235 1213 1191 1150 1129 1110 1090 1071 1053 1035 1017 999 965 949 933 917 901 886 871 857 842 814 801 788 775 762 749 137 725 713 APPENDIX B Temperature Dial Resistance Proper Readings Should Be 5400 6600 Ohms at Minimum Setting And 0 50 Ohms at Maximum Be Careful When Making Voltage Measurements or Jumping Terminals Not to Damage or Deform Connectors or Connector Pins Page 14 LAARS Heating Systems SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement
16. 120 170 UHE60T150 UHE100T199 100 150 UHE60T150 UHE100T199 100 150 UHE60T199 80 130 UHE60T199 80 130 UHE100T250 80 130 UHE100T250 80 130 UHE100T300 60 110 UHE100T300 60 110 UHE100T399 50 100 UHE100T399 50 100 Unbalanced Direct Vent Systems Air intake CAN NOT exceed exhaust by more than 30 feet Note each 3 amp 4 90 Elbow is equivalent to 5 feet of straight pipe Note each 3 amp 4 45 Elbow is equivalent to 2 5 feet of straight pipe Page 44 LAARS Heating Systems Date Service Provider Phone Number Venting PVC CPVC Vent size 3 or 4 Intake 90 s qty Exhaust 90 s qty Gas Line Size material U H E Seri s Heater Service Report Model Number Serial Number Distance from meter to water heater Electrical Line Voltage Igniter Resistance LED Flashing Y or WN Length of straight pipe Intake 45 s qty o intake Length of straight pipe Exhaust 45 s qty exhaust Gas Pressure Venturi Static Setting from Bottom in Turns Running Inlet Manifold Low Voltage Polarity Flame Sense Micro Amps Spark Gap Which One s Error Codes on Control Display Direct Spark Ignition System Only Condensate Line Size Material Length Is trap provided Y or N Combustion Exhaust Collector Pressure Positive Inches W C
17. 5 second flame proving period Is there 24 volts AC at locations P3 2 8 P3 5 A O O Elle Remove flame sensor from water heater p3 268 ae UT a Check continuity from tip of flame sensor N Volt meter set to GOs ener eae Micro amps setting Saye rower i there continuity WA A P5 aan Oe E HA gt PRIMARY vave P1 DA isi FLAME N Meter v en pe arson p r O b e DAD ANSI aca No 9 4 Is flame sensor free Y Is ceramic of flame Cl Ia of oxidation sensor cracked oa os eee 2 Flame 00 sensor terminal Meter ead b Flame sensor O N a N pies terminal on Clean or replace ignition module Replace flame sensor flame sensor with emery see page 33 cloth see page 33 o e No Zz U H E Service Manual Page 33 r Service Procedure UHE VIII Flame Sensor Testing and Replacement Flame Sensor Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Step 11 Step 12 Position main power switch to OFF WARNING Disconnect unplug water heater 120 volt potential exposure Isolate the from 120 volt power source appliance and reconfirm power is Un latch amp remove
18. ASKET and flame sensor from combustion assembly Remove the two screws holding BURNER TRANSITION MOUNTING NUTS GASKET Remove the 4 nuts 7 16 wrench holding the burner transition in place Lift the blower gas valve transition assembly from burner mounting insert remove gasket and set aside BURNER TUBE BURNER MOUNTING INSERT Remove burner tube from burner mounting insert See next page for burner tube inspection procedure U H E Service Manual Page 23 SERVICE PROCEDURE UHE III Burner Tube Inspection and Replacement A WARNING Heater components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury Burner Tube Inspection Step 1 Inspect burner tube as follows BSI ceramic fiber mesh burner water heaters prior to serial number CK a Visually inspect ceramic fiber mesh mesh should be uniform in appearance without large gaps tears or fraying Mesh should have uniform pattern allowing for unrestricted gas low b Gently squeeze burner tube Burner tube should feel firm without any soft areas around the sides or at the bottom c Visually inspect inside burner tube Burner tube should be intact with no areas of deterioration Ports should be free of any debris Inspect burner tube as follows Acotech metal fiber mesh burner water heaters with CK serial number or later a Outer fiber mesh should be uniform
19. Engineering 1869 Sismet Road Mississauga Ontario Canada L4W 1W8 905 238 0100 Fax 905 366 0130 www Laars com Heating Systems Company A subsidiary of BRADFORD WHITE Corporation Litho in U S A Laars Heating Systems 1302 Document 11019A
20. OVE POWER FOR 45 SECONDS TO RESET l a PURCEOS SYSTEM WILL AUTOMATICALLY RE TRY AFTER 1 HOUR Hot surface gt o A auce ERSATT E igniter y CHECK IGNITER IGNITION MODULE RESISTANCE U H E Service Manual Page 31 a Service Procedure UHE VII _ Hot surface Igniter Testing and Replacement Hot surface Igniter Replacement Procedure Step 1 Position main power switch to OFF A WARNING Step 2 Disconnect unplug water heater 120 volt potential exposure Isolate the from 120 volt power source appliance and reconfirm power is Step 3 Un latch amp remove surround cover disconnected using a multi meter from top of heater Step 4 Fold back insulation in front of combustion assembly to expose hot surface igniter see photo at right mm Le A Step 5 Disconnect igniter wire leads from ignition module any Step 6 Remove the 2 igniter mounting screws magnetic tip long reach Phillips screw driver and remove igniter and gasket from transition base flange Step 7 Remove any residual gasket material from transition base flange Note New replacement igniter will Note Do not handle igniter element or allow foreign material to come in contact with element not have a shield over element Handle carefully to prevent breakage y Hot Surface Igniter Step 8 Install new igniter with new gasket provided using screws from step 5 Arrange
21. RNING 120 volt potential exposure Use caution making voltage checks to avoid personal injury Igniter may be too hot to handle take necessary precautions a Refer to ignition module illustration below Is igniter resistance is there 120VAC across terminals less than 150 Ohms Check harness Y P6 1 and P6 2 Y N cold gt oes ee connection from igniter i ae Check during igniter warm up period See see check igniter sat Me to ignition module indicated by the igniter LED glowing on the resistance below pe Ko P C ignition module N N O b Replace Replace ignition module hot surface igniter see page 34 see page 30 a A P2 CONTROL E d Volt meter set to gt 1 He 7 50 LECTRONIC Ps Pe UT OHM setting OO CONTROLS ia WHITE PIN f nn BLOWER A PURGE ARAS p5 oaan ii ee IM PRIMARY valve P1 DDT Hs FME eee j 6 2 FOR OPERATING SEQUENCE TROUBLESHOOTING SEE INSTALLATION 20V AC IN 3 P6 AND OPERATING INSTRUCTION MANUAL Meter probe P7 E 3 SOCKET 1 j ANSI 22420 AUTONATC MON Sisto 24 VAC 0 5AMP 50 60Hz POWERO z IF SYSTEM LOCK OUT REM
22. Service Manual Document 11019A Service Manual for Ultra High Efficiency Water Heaters UHE60T125E NA XA 2 UHE60T150E NA XA 2 UHE60T199E NA XA 2 UHE100T150E NA XA 2 UHE100T199E NA XA 2 UHE100T250E NA XA 2 UHE100T300E NA XA 2 UHE100T399E NA XA 2 Denotes Warranty Years Troubleshooting Guide and Instructions for Service These instructions are to be stored next to the boiler for reference purposes FOR YOUR SAFETY This product must be installed and serviced by a professional service technician qualified in hot water boiler installation and maintenance Improper installation and or operation could create carbon monoxide gas in flue gases which could cause serious injury property damage or death Improper installation and or operation will void the warranty 44 WARNING If the information in this manual is not followed exactly a fire or explosion may result causing property damage personal injury or loss of life Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance Do not touch any electrical switch do not use any phone in your building Immediately call your gas supplier from a nearby phone Follow the gas supplier s instructions If you cannot reach your gas supplier call the fire department Installation and service must be performed by a qualified instal
23. WILL AUTOMATIC FS PURGEO2 IGNTOROS N WARNING 3 VALVEO 3 EXPLOSION HAZARD CAN CAUSE SERIOUS INJURY OR DEATH SIGHT GLASS Venturi adjustment A J h 2 7 4 Y AS aa ZS AG QU VA DA de O pressure tap ZN M e SECONDARY m P3 ELECTRONIC UT CONTROLS HUNTINGTON INDIANA SERIES INTEGRATED WATER HEATER CONTROL FLAMEO 2 fone IGNITION MODULE y Meter probe Hot surface igniter CHECK IGNITER RESISTANCE U H E Service Manual Page 19 ra SERVICE PROCEDURE UHE II g Combustion System Testing and Replacement i Observe burner operation through the sight glass located on the combustion insert mounting flange Normal burner operation should ignite smoothly without evidence of coughing or huffing upon ignition The burner flame should be a blue flame near the burner surface in a uniform flame pattern Occasional yellow or white streaks are normal WARNING 120 volt potential exposure Isolate the
24. and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Step 8 Replace surround cover on top of water heater Page 24 LAARS Heating Systems Service Procedure UHE IV Gas Valve Replacement Gas Valve Replacement Procedure WARNING Step 1 Position main power switch to OFF 120 volt potential exposure Isolate the Step 2 Disconnect unplug water heater from appliance and reconfirm poner IS 120 volt power source disconnected using a multi meter Step 3 Turn off gas supply to water heater Step 4 Un latch remove surround cover from top of heater Step 5 From the gas valve disconnect the gas connection PVC venting wire harness and silicone tubing Step 6 Remove the 2 gas valve mounting screws Torx bit located at the 11 00 O clock 5 00 O clock position on the venturi mounting flange and remove gas valve from water heater Step 7 Remove any residual gasket material from blower and venturi mounting flange Blower gas valve wire harness Gas valve ve assembly IN LZ Gas valve mounting screws 2 places Venturi inlet Blower Venturi mounting flange Step 8 Install new gas valve with new gasket provided Secure gas valve in place using screws from step 6 Step 9 Reconnect PVC venting gas supply silicone tubing amp wi
25. at location N O and COM shown in y photo at right Use a jumper to connect these two See page 14 wires together as shown in photo at right Restore power to heater Did heater cycle on a N Check thermostat sensor for proper resistance Replace OHMS across blue wires N p thermostat sensor Yellow amp Red wires shown jumpered See page 13 Are readings correct Seepage 12 see photo at right z a N Check m harness gt continuity Replace harness Is there Check temperature dial for propa pesletanie a Ne Replace temperature dial See Appendix B N i potentiometer temperature dial resistance Are readings correct seo page TE see photo at right Thermostat Sensor Y Check temperature dial harness continuity Replace harness Is there po Replace thermostat circuit board see page 15 U H E Service Manual Page 13 SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement APPENDIX A Sensor Resistance at Various Temperatures Be Careful When Making Voltage Measurements or Jumping Terminals Not to Damage or Deform Connectors or Connector Pins Draw Water From The T amp P Valve Compare Temperature With Temperature Ohms Chart Below Example If temperature of sensor is 84 F then the resistance through the sensor would be 8449
26. ature Sensor Check continuity through AA ECO red wires of Refer to ignition module thermostat sensor illustration Is there 24VAC Check at temperature between P3 9 and P2 1 less than 160 F 7 Is there continuity see photo at right Replace ignition module see page 34 N Me Ba O O k Check wire harness continuity Replace thermostat sensor or wire harness as necessary see page 17 NS A Replace thermostat circuit board see page 15 U H E Service Manual Page 15 Va SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement s Thermostat Board Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Position main power switch to OFF Disconnect unplug water heater from 120 volt power source Un latch and remove top surround cover from top of heater Locate thermostat board on control panel see photo at right Thermostat Board Carefully disconnect all wires from thermostat board Note it may be necessary to identify wires for proper re connection Remove the two screws Phillips head screw driver that secure thermostat board to control panel Install new thermostat board to control panel using screws from step 6 Carefully reconnect wiring per the wire diagram below Reconfirm wire connections are cor
27. cket Burner tube holding the burner mounting insert in place Step 8 Carefully remove combustion assembly with gasket from water heater Step 9 See next page for combustion system installation procedure Burner mounting insert gasket U H E Service Manual Page 21 ra SERVICE PROCEDURE UHE II g Combustion System Testing and Replacement i Combustion System Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Fully inspect burner mounting insert gasket for the following a Tears d Dirt or debris b Missing material e Other imperfections that would inhibit proper seal c Cracks If gasket is NOT affected by any of the above gasket replacement is not required Install combustion assembly using new gasket or fully inspected gasket from step 1 Secure combustion assembly at the burner mounting insert using screws from step 6 on previous page Tighten screws evenly Reconnect wire harnesses to hot surface igniter flame sensor blower and gas valve Reconnect PVC venting gas supply and silicone tubing to gas valve Turn on gas supply to heater and check for gas leaks repair any gas leaks found Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Gas valve wire harness Replace surround cover
28. connect unplug water heater from disconnected using a multi meter 120 volt power source Step 3 Turn off gas supply to water heater Step 4 Un latch amp remove surround cover from top of heater Step 5 Disconnect wire harness from blower Step 6 Disconnect intake vent and gas supply from gas valve assembly Step 7 Remove the 2 gas valve mounting screws Torx bit located at the 11 00 O clock amp 5 00 O clock position on the venturi mounting flange Step 8 Remove The 4 blower flange mounting screws 5 32 Allen wrench and remove blower from transition flange Blower Blower gas valve k id Gas valve WA assembly Gas valve O mounting screws an 2 places Venturi inlet Blower flange mounting screws Blower transition gasket Venturi mounting flange Transition flange Step 9 Remove any residual gasket material from venturi mounting flange and transition flange Step 10 Install new blower with new gasket provided Secure blower in place using screws from step 8 Step 11 Reconnect gas valve assembly to blower with new gasket provided Secure gas alve in place using screws f tep 7 Step 12 Reconnect intake vent and valve In place using screws trom step gas line to gas valve assembly and check for gas leaks repair any leaks found Step 13 Reconnect wire harness to blower assembly restore 120 volt power supply amp Gas supply to water heater and confirm proper operation follo
29. e supply Power Green Line voltage supply Purge Red WIRING DIAGRAM P2 Igniter Red Valve Red 399 999 BTUH ODELS ONLY Zr TRANSFORMER Pa LEO 2 UT EERON PANRERE pS 24 ae na QE i CONTROLS E i IN na ak Es PS ngs O Doy i E we a SWITCH LIGHT hi E a a E i ine ay o ae adi pune AA E A 0 3 P7 ELECTRONIC a ER a aes dl a E crue anes a E SSPR i PT ooe Suon B Po E Ww me veo Eto ae cas ee POTENTIOMETER l f pe 26 77 vw IGNITOR 90 i O EE oe A l P3 BLOWER a 0 cY Ps Pa 4 BK IGNITION MODULE Ln rd wale SENS 1 GH U R z P3 E w R C COM pS BL a PS 4 gt N O 1 24H GAS VALVE P3 RNO OR si FS BK ELECTRONIC GN 8 i FLAME SENSOR THERMOSTAT Page 10 LAARS Heating Systems O A Troubleshooting System Observation WARNING Is front panel power N Position front panel on reno 120 volt potential exposure Use caution indicating power ON position making voltage checks to avoid personal injury Is there 120VAC across switch see photo at right n Is there 120VAC across terminal block see photo at right Determine power source problem and correct Power Switch Light burned out replace switch Terminal Block Repair replace wire harness to switch oe 9 BY Refer to ignition module Refer to ianition module Refer to ignitio
30. ection and Replacement Flue baffle inspection and replacement A WARNING Heater components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury Step 1 Disassemble heater per Disassembly Procedure for Access to Anodes amp Flue Baffles Step 2 Remove flue baffles from heater pliers 8 two inch baffles amp 2 four inch baffles Step 3 Visually inspect flue baffles Flue baffles should show signs of oxidation this is normal If the oxidation has deteriorated any portion of the flue baffle replacement is recommended If any restrictors are missing replacement is recommended Step 4 Upon completion of inspection or subsequent replacement reinstall flue baffles into heater Step 5 Reinstall collector cover per Collector Cover Installation Procedure see page 42 Step 6 Reinstall collector insulation and control panel reconnect control panel wire harnesses Step 7 Restore 120 volts to water heater and verify proper heater operation following the instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Step 8 Replace surround cover on top of water heater U H E Service Manual Page 41 r Service Procedure UHE XII _ Powered Anode Replacement for UHE100T399 only Powered Anode Replacement UHE100T399 models only A WARNING Heat
31. ep 7 Step 8 Step 9 Position main power switch to OFF Loosen adhesive backed rubber escutcheon from service panel access cover and slide escutcheon back along exhaust pipe to allow for removal of cover see photos at right Remove screws from service panel access cover nut driver and remove cover from heater see photos at right Disconnect wire leads from vent safety switch see photo at right Remove the 2 switch mounting screws Phillips screw driver and nuts 5 16 wrench and remove switch from heater Install new switch using screws from step 5 Reconnect wire leads Note wire leads are interchangeable with either switch terminal Rubber escutcheon Vent safety switch Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Reinstall service panel access cover and rubber escutcheon Page 38 LAARS Heating Systems 7 Service Procedure UHE XII _Anode Flue Baffle Inspection and Replacement Disassembly Procedure for Access to Anodes amp Flue Baffles A WARNING Heater components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury A WARNING Step 1 Position main power switch to OFF 120 vol
32. eplacement a OS Procedure Hot Surface Ignition E a Refer to ignition module Models ONLY control board illustration N Refer to ignition y Hot Surface Ignition Models Y Replace ignition module Is there 120VAC between module is there 24 Are safety circuits in normal position control board P5 1 and P5 3 VAC between P3 7 and ground Ne A a e N N Ad Checking for 120VAC da 2 EN Black amp White Wires Y Thermostat not Correct safety circuit problem per calling for heat safety circuit trace a see page 12 see page 27 Is there 120VAC across the white and Repair revlace black wires at the 3 Z wire harness blower see photo at right x e ELECTRONIC Y P3 UT contos BLOWER P5 TF PIJAT A ne Replace blower 5 gait s E see pag e 25 on e 0 i P6 FOR OPERATING SEQUENCE oom SEE INSTALLATION POWEROS IF SYSTEM LOCK OUT SYSTEM WILL AUT FS PURCEO 2 IGNTORO A WARNING p VADEO A DEA FLAMEO 2 o0 IGNITION MODULE 25 Page 26 LAARS Heating Systems Service Procedure UHE V g Blower Testing and Replacement Blower Replacement Procedure WARNING 120 volt potential exposure Isolate the Step 1 Position main power switch to OFF s appliance and reconfirm power is Step 2 Dis
33. er components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury The powered anode control module is located on the right vertical side of the control panel inside the surround panel The control has a LED indicator light to show the status of operation When the tank is filled with water and the power supply is on to the water heater the light should have a steady green glow to indicate that protection current is flowing and operating normally If the indicator light is not glowing the power supply to the water heater or powered anode system is disconnected Step 1 Check the power supply or wire connections to the powered anode control Step 2 Indicator light diagnostic codes a If the control is flashing red then there is a malfunction with the powered anode system Make sure there are no bare spots in the wire insulation to the powered anode rods Step 3 Check all electrical connections The powered anode rods are insulated from the water heater tank in the bushing a With an ohmeter check continuity between the powered anode terminal and the bushing There should not be continuity If there is continuity replace the powered anode assembly Volt meter set to OHM setting LAA Seda pe ms LED INDICATOR LIGHT POWERED ANODE POWERED ANODE CONTROL MODULE POWERED ANODE POWERED ANODE THERMOSTAT BULB Page 42 LAARS Heatin
34. erial number when ordering service parts Page 46 LAARS Heating Systems a gt Parts List Ne J AA Latch Assy BB Screw 8 32 x Y RHCR CC Ignition Control Assy DD Jacket Head EE Main Power Switch FF Potentiometer GG Combustion Surround JJ Surround Base Customer must specify complete model number and serial number when ordering service parts 2A JA Combustion Surround Assy specify model Blower Gas Valve Assy specify model Burner Assy specify model Blower EBM specify model Silicone Hose Burner Mounting Insert Gasket Screw 10 32 x3 4 Gasket amp Screw Gas Valve specify model 10A Nipple specify model 11A Reducer specify model 12A Nipple specify model l 13A 2 dia Flex Reducer or PVC reducer for 399 14A Inlet PVC 15A Gasket Blower Transition specify model 16A Screw 8 32 x RHCR 17A Gasket Flame Sensor 18A Flame Sensor 19A Transition Tube 20A Nut Hex Washer 21A Gasket Hot Surface Igniter 22A Hot Surface Igniter 23A Burner Mounting Gasket 24A Burner Tube 25A Burner Mounting Gasket 26A Burner Mounting Insert U H E Service Manual Page 47 a A Parts List Na y 1C Electr
35. ete heating cycle and did See next page blower post purge gt PURGEO SYSTEM WILL AUTOMATICALLY RE TRY AFTER 1 HOUR Is ignition module i a IGNITORO 2 THIS DEVICE CAN MALFUNCTION IF IT GETS power a nd fla me light Y Su pply voltage pola rity IS VALVE O 2 CEN oo MAS BEEN WETS REPLACE MM T flashing incorrect P FLAMEO 2 A A O L J i System is OK U H E Service Manual Page 11 Troubleshooting LED status probable cause For models with Hot Surface Ignition Determine failure mode by observing flashing LED status on ignition module LED status and probable cause shown below Denotes conditions that may require the water heater to be isolated from the vent system to determine root cause LED STATUS Only power light is on and water heater will not function a N Probable Cause Exhaust pressure switch see page 27 Ne LED STATUS Purge light flashing O N Probable Cause Exhaust pressure switch see page 27 No P LED STATUS Valve light flashing a N Probable Cause Hot surface igniter see page 30 XN 7 LED STATUS Power amp flame light flashing Probable Cause Supply voltage polarity gt Probable Cause Thermostat circuit see page 12 Probable Cause Blower see page 25 7 Xe Probable Cause Combustion sys
36. g Systems Service Procedure UHE XII Anode Flue Baffle Inspection and Replacement Collector Cover Installation Procedure Step 1 Step 2 Step 3 Step 4 Remove old silicone from top surface of collector flange and collector cover Apply Y4 bead of Ultra Copper Silicone around entire collector flange surface Allow caulk to cure for 10 minutes Carefully reinstall collector cover tighten screws evenly Allow a minimum of 6 hours before putting heater back in service a A E A n tle a S r t aa f gt i J A gt gt q A Pa E da F E s re D d bal ae a as e ion n A g i ie LS 2533 A Y we See ee EET 4 dl F d Apply bead of Ultra Copper Silicone around entire collector flange surface U H E Service Manual Page 43 f Water Heater _Installation Check List Product Handling Carefully uncrate the heater Move in place with a hand truck Do not use the venting pipes for handles Electrical Requirements Make sure there is 120 volts line voltage Line voltage must be properly polarized Adequate ground supplied to the heater Venting Requirements All venting must stay within the required lengths and diameter see table below Proper support of the venting pipe is a MUST every 5ft vertical and 3ft horizontal Termination must be located to prevent re circulation of flue gases Medium to long sweep 90
37. igniter flange with off center hole towards front of heater Off center mounting hole Igniter mounting Igniter flange id Igniter gasket Igniter filament Heater front Transition a base flange Step 9 Reconnect igniter wire harness Step 10 Fold insulation back into place Be sure no wires are in contact with burner flange Step 11 Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instructions located in the installation and operating instruction manual Step 12 Replace surround cover on top of water heater Page 32 LAARS Heating Systems fe Service Procedure UHE VIII _ Flame sensor Testing and Replacement A WARNING 120 volt potential exposure Use caution making voltage checks to avoid Flame Sensor Testing Procedure personal injury Flame sensor may be too hot to handle take necessary precautions O N Refer to illustration below is there a minimum of 1 micro amp during 1 5 second flame proving period DN A y With flame sensor Disconnected from ignition module check Replace flame sensor with Call for continuity to ground gasket and or wire lead technical support Is there continuity to ground see page 33 Refer to ignition module control board illustration 24 volts should maintain beyond the Y a gt l Flame sensing circuit OK 1
38. in running Venting System Power vent balanced direct vent or unbalanced direct vent See vent tables on page 7 Approved Vent Materials PVC CPVC or ABS Minimum Clearance 18 from top 24 from front 4 sides and rear for Servicing Maximum Water Supply Pressure ais Thermostat Sensor 11 900 Ohms 70 F ECO opens 201 F Max ECO close 100 F Min Temperature Dial Min set point 5400 6600 ohms Max set point 0 50 ohms Thermostat Board Max temp 180 F Min temp 91 F 24VAC 60Hz max Ignition Module See page 9 Transformer 120VAC primary 24VAC secondary 40VA Hot Surface Igniter 120VAC 30 120 ohms room temperature Flame Sensor Output Minimum 1 micro amp Typical range 4 to 7 micro amps Gas Valve Negative regulation 24 VAC 7 PSI max 4 5 W C Minimum running inlet Vent Safety Switch Normally closed opens 350 F manual reset Blocked Vent Pressure Switch 24VAC normally closed opens when pressure increases to 2 70 W C Blower 120VAC 60Hz 6 1 amps 6400 RPM Combustion Levels CO2 10 11 CO less then 0 04 percent 400 PPM air free U H E Service Manual Page 7 a a Specifications S P Balanced Direct Vent Systems Power Vented Systems PVC CPVC PVC CPVC Total length of intake piping and eet PIPING Total length of exhaust piping must not exceed
39. ler service agency or gas supplier A AVERTISSEMENT Assurez vous de bien suivres les instructions donn es dans cette notice pour r duire au minimum le risque d incendie ou d explosion ou pour viter tout dommage mat riel toute blessure ou la mort Ne pas entreposer ni utiliser d essence ni d autres vapeurs ou liquides inflammables dans le voisinage de cet appareil ou de tout autre appareil QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ e Ne pas tenter d allumer d appareils Ne touchez a aucun interrupteur Ne pas vous servir des t l phones dansle b timent o vous tes Appelez imm diatement votre fournisseur de gaz depuis un voisin Suivez les instructions du fournisseur Si vous ne pouvez rejoindre le fournisseur de gaz appelez le sservice des incendies L installation et l entretien doivent tre assures par un installateur ou un service d entretien qualifi ou par le fournisseur de gaz Heating Systems Company A subsidiary of BRADFORD WHITE Corporation Page 2 LAARS Heating Systems Heating Systems Company A subsidiary of BRADFORD WHITE Corporation U H E Series Commercial Gas Ultra High Efficiency Water Heaters Table of Contents Page U H E Service Procedure Introduction 3 How to use this manual 4 Tool required for service 4 Specifications 5 Sequence of Operation 8 Troubleshooting 10 Thermostat Circuit Testing amp Replacement 12 I Combustio
40. n System Testing and Replacement 18 II Burner Tube Inspection amp Replacement 22 Il Gas Valve Replacement 24 IV Blower Testing and Replacement 25 V Exhaust Pressure Switch Testing and Replacement oe VI Hot Surface Igniter Testing and Replacement 30 VU Flame Sensor Testing and Replacement 32 VII Ignition Module Control Board Replacement 34 IX Transformer Replacement 35 X Vent Safety Switch Testing and Replacement 36 XI Anode amp Flue Baffle Inspection and Replacement 38 XII Installation Check List 43 Heater Service Report 44 Parts List 45 Glossary of Terms 48 Ss U H E Service Manual Page 3 U H E Series Commercial Gas Ultra High Efficiency Water Heaters Introduction The LAARS heating system Ultra High Efficiency Water Heater is designed to deliver a remarkable thermal efficiency rating in a quiet running unit with venting options that allow for installation flexibility Several technologically advanced design features are incorporated in the design that will require additional knowledge on the part of the qualified service provider The information in this manual will instruct service and maintenance professionals on the function proper diagnosis and repair of LAARS Heating System Ultra High Efficiency Water Heater The LAARS heating system Ultra High Efficiency Water Heater uses a low Nox premix power burner located at the top of the water heater to direct a turbulent flame down into a submerged combustion chamber
41. n module Is ignition module N illustration is there 120VAC Y ustration 9 there 120VAC Y illustration is there 24VAC power light on going to module at locations eo nee P1 1 and P1 3 going to module at locations P7 1 and P7 3 P2 1 and Y i N YN Replace ignition module Replace ignition module transformer see page 24 see page 24 see page 35 P2 1 y O O CONTROL ape 2h LECTRONIC P3 Te ss UT CONTROLS WHITE PIN IGNITION MODULE SECONDARY p HUNTINGTON INDIANA 1013 SERIES INTEGRATED WATER HEATER CONTROL Power BLOWER P5 23 2 INDICATOR PURGE IGNIT RED PIN LIGHTS GNITOR VALVE PRIMARY FLAVE P1 DOT AS ane ira 2 FOR OPERATING SEQUENCE TROUBLESHOOTING SEE INSTALLATION 4 S AND OPERATING INSTRUCTION MANUAL 20V AC IN 3 P7 pg RED SOCKET ANSI Z21 20 AUTOMATIC IGNITION SYSTEMS CAN CSA 22 2 NO 199 M89 24 VAC O 5AMP 50 60Hz POWERO Z IF SYSTEM LOCK OUT REMOVE POWER FOR 45 SECONDS TO RESET J Reset heater by interrupting power Reestablish power and Adjust thermostat to Allow heater to run call for heat through heating cycle tank must be cold Did heater compl
42. ning see illustrations at right Z Y drop more than 2 W C Reconfigure gas supply piping Inadequately sized regulator J N Is gas supply pressure regulator adjustable to Y maintain proper and stable setting Adjust gas supply regulator A Does inlet gas pressure a during burner ignition N Y Do you see the igniter glowing through burner N site glass during the warm up period Y A WARNING 120 volt potential exposure Use caution making voltage checks to avoid personal injury A WARNING Removing screw from inlet gas pressure tap will immediately allow gas to flow from pressure tap Replace ignition module see page 34 N Refer to ignition module illustration below is there 120VAC across terminals P6 1 and P6 2 Note Igniter LED must be lit during this check Y a Is igniter resistance gt less than 150 Ohms cold see check igniter illustration J Z Volt meter set to OHM setting Replace hot surface igniter see page 30 O Proceed to next page MN P3 POWER BLOWER 2 3 PURGE aa NE VANE INDICATOR P5 ADOT Icnrror RED P LIGHTS PRIMARY D HSI lid AE FOR OPERATING SEQUENCE TROUBLESHO TALLATION 20V AC IN P6 OPERATING INSTRUCTI DDD A POWERO Z IF SYSTEM LOCK OUT REMOVE SYSTEM
43. on top of water heater Gas connection Burner mounting screw Total of 5 PVC vent connection Burner mounting insert Burner tube Burner mounting insert gasket Page 22 LAARS Heating Systems SERVICE PROCEDURE UHE III Burner Tube Inspection and Replacement A WARNING Heater components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury Burner Tube Removal Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Position main power switch to OFF A WARNING 120 volt potential exposure Isolate the Disconnect unplug water heater from 120 volt power source appliance and reconfirm power is disconnected using a multi meter Turn off gas supply to water heater Un latch amp remove surround cover from top of GAS VALVE heater S WIRE HARNESS From the gas valve disconnect the gas connection PVC venting wire harness and silicone tubing BLOWER GAS VALVE TRANSITION Disconnect wire harness from ASSEMBLY blower assembly p FLAME aly TRANSITION SENSOR ALF a AZ HOT SURFACE 2 NITER SPARK Av ROD ez PVC VENT i CONNECTION each the hot surface igniter and as fo flame sensor in place long reach CC CD magnetic Phillips screw driver BURNER FLANGE ED Carefully remove hot surface igniter G
44. onic Control Module 2C Screw 8 32 x 1 2 3C Control Mounting Panel 4C Thermostat PC Board 5C Transformer 120VAC x 24VAC x 40VA 6C Terminal 7C Terminal Strip 8C Power Cord 9C Control Wire Harness 10C Thermostat Wire Harness 11C Rectifier Harness specify model 12C Blower Wire Harness specify model 13C Power Switch Wire Harness 14C Flame Sensor Wire Harness 15C Powered Anode Control Harness 399 only 16C Powered Anode Harness 399 only 17C Powered Anode Control 399 only Customer must specify complete model number and serial number when ordering service parts Page 48 LAARS Heating Systems b Glossary of Terms A AC Alternating Current BTU H British Thermal Units CO Carbon Monoxide CO2 Carbon Dioxide DC Direct Current DSI Direct Spark Ignition ECO Energy Cut Off GFI Ground fault interrupt GPM Gallons per Minute HSI Hot Surface Igniter Hz Hertz LED Light Emitting Diode NOx Oxides of Nitrogen NPT National Pipe Thread PSI Pounds per Square Inch RPM Revolutions per Minute VA Volt Amps VAC Volts Alternating Current W C Inches of Water Column C Degrees Centigrade s Degrees Fahrenheit UA Micro Amp NOTES 800 900 9276 Fax 800 559 1583 Customer Service Service Advisors 20 Industrial Way Rochester NH 03867 603 335 6300 Fax 603 335 3355 Applications
45. ort O N Check PURGE LED status Y Replace exhaust Depress reset on ignition module pressure switch see N button on vent Flashing after 45 seconds page 29 Mncton across high limit y switch Qe se a side see photo below harness harness e Verify proper yn switch operation see page 36 Replace vent safety Woe MR switch Check PURGE LED status see page 37 A a a ii on within 5 minutes Pol Pressure switch is OK Y N C Fla shing after 5 minutes N Call for technical Error code 29 again support Y tone tor proper Correct blower problem operation see page 25 see page 25 Is blower OK Reset button Vy Check Collector Pressure Refer to see next page N ote HOT SURFACE IGNITION MODELS ONLY The blocked vent pressure switch A WARNING Make sure exhaust collector compartment is not must be used with the revised ignition control overheating 350 F before resetting vent safety identified with a yellow label switch If there is evidence the collector compartment is overheating CALL TECHNICAL SUPPORT Does heater Y Saey ano de 5 there continuity A Page 28 LAARS Heating Systems Da Ne Service Procedure UHE VI Exhaust Pressure Switch Testing and Replacement
46. ort Y Does burner operate Does flame LED on the module normaly until thermostat is light and stay lit satisfied Y Gas valve Check flame sensor regulator Is there 1 to 5 micro amps min during 1 5 second gt System OK flame proving period y see page 32 UHE100T399 A Only N Replace flame sensor see page 32 Page 20 LAARS Heating Systems r SERVICE PROCEDURE UHE II E Combustion System Testing and Replacement A WARNING Heater components may be HOT when performing the following steps in this procedure Take necessary precaution to prevent personal injury Combustion System Removal Procedure Step 1 Position main power switch to OFF WARNING 120 volt potential exposure Isolate the Step 2 Disconnect unplug water heater from appliance and reconfirm power is 120 volt power source disconnected using a multi meter Step 3 Turn off gas supply to water heater Gas valve wire harness Step 4 Un latch and remove surround cover from top of heater Step 5 From the gas valve disconnect the gas connection PVC venting Silicone tubing and wire harness i Gas P connection Step 6 Disconnect wire harnesses flame sensor and Blower Disconnect wire harness from hot surface igniter Burner mounting screw Total of 5 N PVC vent connection Burner mounting insert Step 7 Remove the 5 bolts so
47. otos above Reconnect wires to potentiometer Note Wire leads are interchangeable with either wire Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Replace surround cover on top of heater U H E Service Manual Page 17 3 SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement Thermostat Sensor Thermistor Replacement Procedure Step 1 Position main power switch to OFF ARWARNING Step 2 Disconnect unplug water heater from 120 volt potential SANOS are Isolate the 120 volt power source appliance and reconfirm power is disconnected using a multi meter Step 3 Drain water heater down to a point below the top of the tank Step 4 Un latch and remove top surround cover from top of heater Step 5 Fold back insulation just in front of burner to expose temperature sensor see photo below Step 6 Disconnect temperature sensor from harness see photos at right h ES Disconnect sensor Me C from harness io Hot Surface Ignition Models F Insulation folded back to expose temperature sensor Step 7 Remove temperature sensor 1 1 16 hex deep well socket from heater Note Using a deep well socket will allow room inside socket for sensor connector and wires Ste
48. p 8 Apply thread sealing tape or applicable thread lubricant to threads of new sensor Install new thermostat sensor and Connect to wire harness from step 6 Step 9 Fold insulation back into place Be sure there are no wires in contact with burner Step 10 Restore 120 volt power supply and water supply to water heater check and repair any leaks found Confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Step 11 Replace surround cover on top of heater Page 18 LAARS Heating Systems SERVICE PROCEDURE UHE II a Combustion System Testing and Replacement i Observe burner operation through the sight glass located on the combustion insert mounting flange Normal burner operation should ignite smoothly without evidence of coughing or huffing upon ignition The burner flame should be a blue flame near the burner surface in a uniform flame pattern Occasional yellow or white streaks are normal Note On higher input models using metal fiber mesh burner serial number CK and later a red glow from the burner surface is normal Verify Minimum Gas Supply Piping Requirements of N Minimum 1 NPT for UHE100T399 all others use 3 4 NPT Schedule 40 black Iron Pipe recommended With manometer check inlet gas pressure Is it stable between 7 8 14 W C static heater not run
49. r U H E Service Manual Page 35 Va Service Procedure UHE X Transformer Replacement Transformer Replacement Procedure Step 1 Position main power switch to OFF A WARNING Step 2 Disconnect Unplug water heater 120 volt potential exposure Isolate the from 120 Volt power source appliance and reconfirm power is Step 3 Un latch amp remove surround cover from disconnected using a multi meter top of water heater Step 4 For Hot Surface Ignition models refer to ignition module illustration below Disconnect wire harness P1 labeled PRIMARY and P2 labeled SECONDARY from ignition module o Step 3 Fe Disconnect harness i z p1 amp po Step 5 Disconnect secondary leads blue amp F ETRA from ignition module yellow wire from thermostat board U Loros Note the blue wire is connected to GANA 24 volt HOT terminal see photo below sous Frome PS A mee HEr PRIMARY E P1 3 D HS FLAME T os pg COTE P7 90T E esa Disconnect blue amp yellow wire from ninco Sega eine thermostat board Note blue wireis Ep gt os E qu id connected to 24 volt HOT terminal E o9 Ignition module Thermostat board Step 6 Remove the 2 screws short Phillips screw driver holding the
50. re harness to gas valve Turn on gas supply to heater and check for gas leaks repair any gas leaks found Step 10 Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Step 11 Replace surround cover on top of water heater U H E Service Manual Page 25 Service Procedure UHE V g Blower Testing and Replacement O N a N Is there 120VAC N y across the white and y Refer to ignition module control board N Replace m gt black wires atthe illustration Is there 120VAC between P5 1 and ignition module Does blower terminal block P5 3 control board energize see photo at right C E E J N Y Se a N 120VAC check at Terminal Block Determine power source problem and correct AS Black wire leading to blower motor looped through amprobe Y O N y Is there 120VAC O N across the white and N Check amp draw through black wires at the BLACK wire lead of blower Y Is Blower wheel secured to Y Call technical terminal block motor Is there 6 to 3 0 blower motor shaft support amps Ne J Y k P N N Replace blower v see Blower R
51. rect prior to putting heater back in service Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instruction located in the installation and operating instruction manual Replace surround cover on top of heater WARNING 120 volt potential exposure Isolate the appliance and reconfirm power is disconnected using a multi meter Mounting screw locations Pp 399 9 OWERED ANODE ON 99 BTUH MODELS ONLY L 2 TRANSFORMER WIRING DIAGRAM 115V AC INPUT N Ma ER 24V AC OUTPUT GN Y BK Bl BL T CN BK W Y TOGGLE SWITCH LIGHT gt A NA bs hh P2 P2 Pi P1 PI 115 VOLTS AC N ve 3 P7 ELECTRONIC py CONTROL MODULE GND GN Y 2 11 BK e BK gt 1 P7 TOGGLE SWITCH A wn D me y i POTENTIOMETER P6 2 W ignitor Y 9 N C TEMP SWITCH P3 BLOWER 2 9 UPPER et 6 MOTOR hed SENSOR x T PS Q 4 NF z GAR pe E ae POT BL ey X SUR P S N C 5 sai 98 U ign P ay w LOWER S 1 a CICOM 24y 22 WY BL 4 2 P5 a NO T 24H GAS VALVE 5 PS z R FS BK J 0 ELECTRONIC GN 8 FLAME SENSOR THERMOSTAT Page 16 LAARS Heating Systems
52. sed to measure electrical values The meter you select must have the capability to measure volts AC volts DC Amps micro amps and ohms Thermometer Used to measure water temperature An accurate thermometer is recommended Water Pressure Gage Used to measure water supply pressure Also used to determine tank pressure by adapting to the drain valve of the heater Jumper Leads A length of wire 12 min with alligator clip at both ends Various Hand Tools Pipe wrench channel locks open end wrench set 12 crescent wrench Allen wrench set torx bit set screw drivers common amp phillips long reach 12 magnetic tip phillips head screw driver 2 tip nut driver pliers Common amp needle nose socket set including a 1 1 16 deep well socket wire cutters wire strippers wire crimpers torpedo level small shop vac step ladder and flashlight U H E Service Manual Page 5 Specifications 3 PVC COMBUSTION AIR INLET GAS CONNECTION SEE TABLE THERMOSTAT KNOB ON OFF SWITCH A gt T de P RELIEF VALVE E AA 1 NPT SIDE OUTLET 1 1 2 NPT HOT WATER OUTLET 1 1 2 NPT COLD WATER INLET 1 NPT SIDE INLET 3 4 DRAIN TOP_VIEW disen DIMENSIONS INCHES at Degree Rise 4St Hr A B C D E F G H Input Del i Gal Stg Therm Ht Dia Flr Firto Firto Fir To Flr To Flirto Front Space Gas T amp P Shpg Model No Rate 40 F 100 F 140 F Cap Eff to Inlet T amp P Ou
53. surround cover disconnected using a multi meter from top of heater Fold back insulation in front of combustion assembly to expose flame sensor see photo at right Disconnect wire lead from flame sensor Remove the 2 sensor mounting screws magnetic tip long reach Phillips screw driver and remove flame sensor amp gasket from transition base flange Remove any residual gasket material from transition base flange O Flame s sensor r h Install new flame sensor with new gasket provided using screws from step 6 Arrange flame sensor with hook towards burner J fA AD A Qf Flame sensor FA Mm gt E mounting screws h LY KDW gt AN Flame sensor Flame sensor gasket Arrange hook of sensor towards burner E SS S amp S Fold insulation back into place Be sure no wires are in contact with burner flange Transition base flange Reconnect flame sensor wire Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions on the lighting instruction label or the lighting instructions located in the installation and operating instruction manual Replace surround cover on top of water heater Page 34 LAARS Heating Systems 7 Service Procedure UHE IX Ignition Module Control Board Replacement Ignition Module Replacement Procedure Step 1 Step 2 Step 3 Step 4 Step 5 Step 6
54. t potential exposure Isolate the Step 2 Disconnect Unplug water heater appliance and reconfirm power is from 120 Volt power source disconnected using a multi meter Step 3 Un latch amp remove surround cover from top of heater Step 4 Disconnect wire harnesses to allow for removal of control panel Note Where ever possible rather than disconnecting at the control panel follow wire harness away from control panel and disconnect at control component location Step 5 Remove the three control panel mounting screws V4 nut driver and remove control panel from the water heater see photos below Remove Control Panel Control Panel Mounting Screw Step 6 Completely remove insulation two pieces from top of heater to expose collector cover Step 7 Remove all collector cover screws 5 16 socket and remove collector cover see photos at right Collector cover Step 8 Photo 44 shows heater with collector cover removed allowing access to anode rods and flue baffles Anode locations a for anode service see page 39 b for flue baffle service see page 40 c for powered anode service see page 41 baffles o Flue Note UHE100T399 models have only 1 anode rod under the 2 pass collector cover U H E Service Manual Page 39 4 Service Procedure UHE XII _Anode Flue Baffle Inspection and Replacement Anode inspection and replacement A
55. tch contacts open Check for obstruction in exhaust pipe and vent terminal Check for blocked condensate trap or drain line In cold climates make sure drain is not frozen No ignition after 3 attempts a Check inlet and outlet gas pressures pressure taps located on top of gas valve b Igniter resistance too high lower resistance preferred lt 150 ohms c Misadjusted veturi screw should be 6 5 turns out from bottom d Flame sense microamp not present 1 0 microamps minimum should be 5 microamps or more If burner lit check flame rod for deposits e Check burner tube condition Refer to section UHE III for Burner Tube Inspection and Replacement Ignition Module Specifications Control Functions Ignition amp heating functions in response to thermostat Hot surface ignition using a microprocessor to control timing flame sensing using flame rectification amp ignition retries Monitoring of system pressure switches and limit switches Control of gas valve inducer motor and hot surface igniter element based on thermostat demand and status of safety inputs Diagnostic indicators to provide information on power to control and control status Non interchangeable polarized plug in connectors for all interconnections Control Inputs Control Outputs Thermostat call for heat Inducer motor Blocked vent pressure switch Hot surface igniter normally closed Gas valve Flame sensing Status indicator LEDs Low voltag
56. tem gt see page 18 y Probable Cause Vent safety switch see page 36 A Probable Cause Flame sensor see page 32 A Page 12 LAARS Heating Systems SERVICE PROCEDURE UHE I _ Thermostat Circuit Testing and Replacement P2 CONTROL Pi IMPORTANT NOTE This procedure assumes a cool tank PSP UT SOO waite PIN C O N TR O is A WAR N N G 1013 SERIES ji es CONTROL POWER Rotate nape 120 volt potential exposure Use NOON momoe oros dial to highest setting 7 LA LIGHTS 0 CNITOR caution making voltage checks a 7 au J ASI to avoid personal injury ae oe Pg ie ma 1 iti g 3 Z 1 i ANSI Z21 20 AUTOMATIC IGNITION SYSTEMS Refer to ignition module dci cnyesi 722 No 05 illustration Is there 24VAC a POWERO z IF SYSTEM A POMER OR PSO TO RESET between P3 7 and P3 8 i o A THIS DEVICE CAN MALFUNCTION IF IT GETS ED VALVE O Z BON Dc ee HAS BEEN WETe AEPIACE TE N OK thermostat is 5 i O calling for heat IGNITION MODULE Thermostat po Red Wire gt Af Yellow Wire COM 8 gt Turn off power to heater Disconnect YELLOW and RED wires from the thermostat board
57. thin Maximum Combined Length from table above Page 8 LAARS Heating Systems r Sequence of Operation pa A G Thermostat calls for heat Q a Prior to energizing blower ignition module checks to make sure the vent temperature switch is in the normally closed position If the vent temperature switch is open the control waits indefinitely for the temperature switch to close Blower energizes pressure switch contacts are normally closed If the pressure switch contacts are open blower operates for up to 5 minutes waiting for contacts to close then blower stops and flashes red PURGE LED indicating lock out condition Blower pre purge period 5 seconds indicated by PURGE LED on the module Igniter warm up 18 seconds indicated by the IGNITER LED on the module Note The blocked vent pressure switch must be in the normally closed position for the ignition cycle to start G Trial for Ignition 4 seconds 3 trials OOO a Flame establishing period 2 5 seconds gas valve and igniter on indicated by the IGNITER and VALVE LED on the module b Burner on flame proving period 1 5 seconds looking for minimum of 1 micro amps indicated by the FLAME amp VALVE LED on the module Steady state operation Ignition module monitors Thermostat circuit When thermostat opens gas valve is shut down and post purge begins Safety circuit If vent temperature switch opens gas valve is shut
58. tlet Air Gas Wtr Heating Conn Valve Wt BTU h 100 F U S Vent Wtr Valve Wtr Intake Conn Conn Conn Dia Open lbs Rise Gal Outlet Conn Conn Conn Dia Dia NPT NPT UHE60T125 125 000 187 363 6 145 5 103 9 60 96 0 57 28 Ya 5 13 40 42 Ya 52 53 1 1 Ya Ya 570 UHE60T150 150 000 211 422 7 169 1 120 8 60 93 0 57 28 Ya 5 13 40 42 Ya 52 53 N 1 1 Ya Ya 570 UHE60T199 199 999 265 557 6 223 158 60 92 0 57 28 Ya 5 13 40 42 Ya 52 53 1 1 Ya Ya 570 UHE100T150 150 000 250 450 5 180 2 129 100 99 1 775 8 28 5 13 60 62 73118 74 1 1 Ya Ya 900 UHE100T199 199 999 309 597 238 8 171 100 98 5 775 8 28 5 13 60 62 73118 74 1 1 Ya Ya 900 UHE100T250 250 000 364 734 8 293 9 210 100 97 0 775 8 28 5 13 60 62 73 1 8 74 1 1 Ya a 900 UHE100T300 300 000 405 836 4 334 5 239 100 92 0 775 8 28 5 13 60 62 73118 74 1 1 Ya Ya 900 UHE100T399 399 999 521 1 127 451 322 100 93 0 775 8 28 5 13 60 62 731 8 73 1 1 1 1 950 Page 6 LAARS Heating Systems O N Specifications pa y Power supply Dedicated 120 VAC 60 Hz 15A GFI Minimum 1 NPT for UHE100T399 all others 34 NPT Gas Supply schedule 40 black iron pipe recommended Approved Gas Type Natural or Propane Unit must match gas type supplied Gas Pressure Nat 8 L P 14 0 W C maximum static 4 5 W C minimum running recommend 7 0 W C m
59. transformer in place and remove transformer from control panel see photo below Step 7 Install new transformer and secure in Step 6 place with screws from step 6 Remove transformer amp mounting screws xX Step 8 Reconnect wire harness P1 amp P2 connections are non interchangeable to insure proper reconnection Step 9 Reconnect blue amp yellow wire leading from the P2 connection on ignition module to Thermostat thermostat board Note the blue wire must connect to the 24 volt HOT terminal see photo at right board Step 10 Restore 120 volt power supply to water heater and confirm proper operation following the lighting Ses Cem D i yellow wire connection instructions on the lighting instruction label or the lighting instruction located in the installation and 24 volt Hot operating instruction manual blue wire connection Step 11 Replace surround cover on top of water heater Page 36 LAARS Heating Systems a Service Procedure UHE XI _Vent Safety Switch Testing and Replacement O N Sequence of operation With the thermostat calling for heat prior to energizing blower the ignition module checks the vent safety switch for normal switch position of normally closed If the vent safety switch contacts are open not in normal position the ignition module waits indefinitely for contact to close The vent safety switch must be manually reset to close the switch contacts ja E
60. wing the lighting instructions on the lighting instruction label or the lighting instructions located in the installation and operating instruction manual Step 14 Replace surround cover on top of water heater U H E Service Manual Page 27 la Service Procedure UHE VI Ne N Exhaust Pressure Switch Testing and Replacement H r Sequence of operation The blocked vent pressure switch monitors the pressure in the exhaust tube The switch contacts are normally closed and will not open unless there is a blockage in the exhaust venting or terminal snow ice debris If the blocked vent pressure switch contacts open after the thermostat initiates the blower the blower will remain on for to 5 minutes waiting for the contacts to close If the contacts remain open the blower will stop and the PURGE LED will flash for hot surface ignition models A a e WARNING LED Status 120 volt potential exposure Use caution Only power LED is on or ne ee l making voltage checks to avoid personal injury Purge LED flashing Sat Circ E S r y Is there continuity Is there continuity Does blower k N Through GREY y through RED N Safety Circuit OK energize gt wire leads of heater side gt wire leads of heater side see page 36 l safety circuit harness safety circuit harness pag y see photo below see photo below pee eee ee l N Call technical supp
61. with no tears or deterioration Step 2 If burner tube is affected by any of the above replacement is required Refer to burner tube replacement procedure below Burner Tube Replacement Procedure Note New metal fiber mesh burner Acotech is the replacement burner for the BSI ceramic fiber sock burner The length of burner will not be the same as the previous BSI burner Provide the model and serial number for the correct replacement burner Step 1 Fully inspect burner flange gaskets igniter and flame sensor gaskets for the following a Tears d Dirt or debris b Missing material e Other imperfections that would inhibit proper seal c Cracks If gaskets are NOT affected by any of the above gasket replacement is not required Step 2 Install burner tube with gaskets into burner mounting insert Be sure gasket surfaces are free of debris Step 3 Reconnect the blower gas valve transition assembly to burner mounting insert Secure using nuts from step 8 on previous page Step 4 Carefully reinstall flame sensor with gasket and hot surface igniter with gasket and secure with screws from step 7 on previous page Reconnect wire harnesses to sensor and igniter Step 5 Reconnect wire harnesses to blower motor and to gas valve Step 6 Reconnect PVC venting gas supply and silicone tubing to gas valve Turn on gas to heater and check for gas leaks repair any gas leaks found Step 7 Restore 120 volt power supply to water heater

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