CMF Furnace
Contents
1. 16 17 OIO GaS COME SO 18 22 Winnog Diagra MSas 23 24 CAUTION This service manual is primarily intended to assist qualified individuals experienced in servicing heating and air conditioning appliances and is not intended to be used by unqualified personnel Performing service as outlined in this service manual will require the use of calibratedtest instruments Using uncalibrated test instruments will result in faulty diagnoses All instruments should be used in accordance with the manufacturer s instructions Figure 1 These instructions are intended for use by qualified individu als specially trained and experienced in installation of this type of equipment and related system components Installa tion and service personnel are required by some governing bodies to be licensed Persons not qualified should not attempt to install or service the equipment nor interpret these instructions These furnaces must be installed in accordance with local codes and ordinances These furnaces are high quality direct vent furnaces that are convertible from power oil to power gas The PO models are Power Oil The PG models are Power Gas models Gas models are designed for operation with natural or LP gas The furnaces are Listed by Underwriters Inc for use in manufactured mobile homes and recr2. Improperly Replace with Improper Short Too Large Flue Located Proper Nozzle Flue Circuit Nozzle Obstruction Electrodes Capacity Nozzle Installed Replace Solid Air Cracked Insulator Mismatched Improper Too Far Cone Design Restriction Spray amp Chimney Draft Forward With Hollow Layer of Soot or Oil Atomizing Design Semi Solid Pattern Design Air Shutter il Fan Blades Oil Tener FanBlades Opening Too Combustion Sica Wide Head Assembled 9 Some Models or Located Improperly Oil Pressure Excessive Air Through Burner Clogged Nozzle Oil Pressure Too Low Damaged Combustion Delayed Ignition Leaky Nozzle Replace Hollow Chamber or Cone Design Burner Tube Sallo and Choke one Nozzle Install Delayed Opening Solenoid on Nozzle Line Nozzle Restriction Too Low Improper Drawer Oil Pressure Assembly Adjustment Airi Defective ir in Nozzle Fuel Line Supply Line Filter Tank Sediment Return Air Restriction Air Adjustment Negative Pressure Around Carbon Build up Furnace on Combustion Chamber Walls Return Air Shortage Replace Hollow Cone Design with Solid Cone Nozzle Oil Viscosity Too High Increase Pump Pressure to 120 125 PSI Use Next Smallest Size Nozzle Oil Burner Operation Complaints Oil and Coke Improper Collect Around Oil Drips from Flue Gas Nozzle and Combustion Head
3. Figure 20 Figure 21 2 1 2 long ARC from the alternate terminal post to the casing The first test of the ignition transformer is to check for continuity using an ohmmeter An infinity reading indicates a defective transformer A 10 000 volt voltmeter is recommended to test the ignition transformer spark 3 1 long ARC from terminal to terminal Removing the Ignitor Transformer 1 Shut off power to the unit 2 Remove white and black wires coming from transformer 3 Loosen 2 5 16 screws and turn on tie down plates 4 Fold back transformer and remove 2 Phillips head screws and transformer 5 To replace reverse steps 1 4 Electrode Setting See Figure 21 The electrode setting is carefully checked at the factory When servicing the burner electrodes three procedures should be performed 1 Set the spacing 2 Set gap 3 Remove the carbon accumulation 4 Refer to Installation Instructions Removing Drawer Assembly 1 Shut off and disconnect power to unit 2 Remove copper oil line from drawer assembly and loosen at pump using a 7 16 open end wrench and move out of way Mark position of lock plate Loosen 5 16 screw on lock plate Remove drawer assembly and set the spacing gap and remove any carbon accumulation 6 To replace reverse steps 1 5 Figure 23 Figure 22 The three functions of the atomizing nozzle are atomization creating the oil
4. 2 Unwire electrical supply 3 Remove 2 1 4 screws 4 To replace reverse steps 1 3 Limit switch can be either manual or automatic reset Manual reset limit will be approved on serial date codes of 9706 and later Testing the Fan Switch The steps necessary to check the operation of the fan switch in the air circulation circuit are 1 Turn off power to unit 2 Turn voltmeter on and set to scale capable of reading 120V 3 Place leads from voltmeter on both wires of the fan switch 4 Turn on 120 volt power supply to furnace Voltmeter should read 120V 10 5 With voltmeter leads still attached set room thermostat above the room temperature until the burner comes on 6 Watch the dial on the fan switch as the heat exchanger heats up the dial should start to rotate When the fan switch reaches the on temperature setting the blower should come on and 0 volts should be read indicating closed switch Removing the Fan Switch Shut off power to unit Remove cover Disconnect wires Remove 3 1 4 screws To replace reverse steps 1 4 IRN Testing Fan Blower Motor See Figure 6 1 Check for 120 Volts 10 2 Check amperage while unit is running 3 Visually inspect wheel and motor mounting Removing Blower Motor Turn off power to furnace Disconnect power wires Remove two 1 2 screws Slide blower out Remove 3 3 8 screws Remove blower and blower wheel Remove blower wheel To reinst
5. Draft Burner Overfiring 4 Conduct Smoke Test Take Sample At Hole in Flue And Compare To Smoke Sale Less Than 1 Spot CO2 High Over 11 2 Low Under 10 1 2 No Smoke on Disc Overfiring of Unit Oil Rate Too High Too Little Excess Air Dirty Fan or Air Handling Parts Faulty Nozzle Operation Faulty Combustion Chamber Air Leaks in Furnace Air Shutter Open Too Wide Excessive Draft Excess Air Set Too High Poor Nozzle Operation Inspection Door Above Burner Calculate Combustion Efficiency Conduct Over Fire Draft Test Plug 1 4 Hole in Flue Set Horizontal Test At Scale on Efficiency Finder to Correct Net Stack Temperature Pressure Drop of 005 to Set Green Arrow 015 WC On Vertical Over Fire Draft Scale of 01 to to 95 2 03 WC Good Read Combustion Efficiency and Stack Loss Defective or Blocked Stack Draft Chimney 02 to 04 WC Less 01 WC Over Fire Draft Soot in Heat Exchanger Stack Draft Over 05 WC Too Short Draft Stack Over Defective or 03 WC Improperly Over Fire Installed Flue Draft Oil Burner Operation Complaints Delayed Ignition Furnace Room Smoky Fire Odors Noisy Fire Long Fire Noise or Pulsation on Stop Start Improper Too Small Wrong Too Low Electrode i ray Angle Nozzle Oil Pressure Setting Spray Ang Improper Over Fire Draft
6. fitting on burner pump and remove fuel line 3 Loosen and remove the three 3 2 16 hex nuts and remove the burner 4 Inspect the combustion chamber and heat exchanger for cracks corrosion or soot If signs of sooting are present the heat exchanger should be cleaned to insure proper draft Installing Gas Burner Figure 1 1 Place new burner gasket on mounting plate See Figure 3 Insert burner tube into heat exchanger through mounting flange Mount burner studs making sure Connect gas piping and check for leaks burner will pull up tight to flange and fasten to mounting a Gas piping should be sized and installed in accordance flange using the three hex nuts with local codes and utility regulations 2 Reconnectthermostatleadsto appropriate connections 4 Thermostat may be necessary to change the heat on burner Attached power cord may then be plugged into 120v receptacle 18 anticipator setting Failure to do so could result in a wide temperature fluctuation in home 120V Receptacle Primary Control Fuel Line Fitting Studs X 2 Burner Gasket Figure 3 Thermostat Connections Figure 4 WARNING FOR YOUR SAFETY WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance Do not use any electrical switch do not use any phone in your building Immediately call your gas supplier from a neighbor s phone Follow the gas supplie
7. start 120 volts is available at AMP plug Ignitor does not heat up 1 2 4 Disconnect burner plug from furnace receptacle Disconnect AMP plug from burner tube receptacle and check ignitor circuit through receptacle with an ohmmeter a Normal ohm reading should be 40 to 75 ohms b An infinite or zero ohm reading indicates a defective ignitor and it must be replaced Check for continuity from ignitor receptacle to burner ground Check for hairline cracks in ignitor s insulating ceramic Main flame ignites but burner locks out 1 2 Ignition control is not properly grounded Defective ignition control Improper gas pressure or burner air adjustment is not allowing flame to contact ignitor tip for flame proving rectification 24 volts supplied to gas valve during ignition but no main gas flow 1 Gas valve may be defective Replace if necessary 2 Gas piping may be plugged Check for adequate gas supply to gas valve at union Burner operates insufficient heat 1 Check the thermostat for proper setting and location The thermostat should not be located where it will be affected by another heat source Lamps ovens sunlight etc Check for clean air filters and proper air flow Check burner for proper gas firing rate Be sure unit is not undersized for its thermal load Check thermostat anticipator 0 9 amps Burner does not shut off Note Burner will stop when the door swi
8. vacuum for every 90 elbow fitting The single stage design is used in applications requiring 10 of vacuum or less Two stage pumps are specified when up to 15 of vacuum is required If an oil fuel pump is not properly sized to the vacuum requirements the following will occur 1 Asolid column of oil willnotbe delivered to the atomizing nozzle 2 The light portions of the oil will separate from the heavy portion 3 A milky appearance will be seen in the returned oil Conversion from Natural Gas to Propane A WARNING Before beginning conversion shut off elec trical power to the furnace at the main power source Shut off gas supply 1 Disconnection a Low voltage wires b Shut off gas to appliance and remove piping to gas valve 2 Remove 3 3 8 bolts from U shaped manifold plate and orifice assembly See Figure 4 Page 19 3 Replace alternate fuel orifice Using a 1 2 open end wrench remove the main orifice and replace it with the alternate fuel orifice supplied in the plastic bag with the burner located with the home owners packet 4 Invert the regulator cap Warning check for proper orifice size listed on furnace rating plate 5 Toreinstall reverse steps 1 4 Manifold pressure would then be set to 11 0 W C for LP gas Changing Complete Burner Assembly See Figures 1 page 18 and Figures 2 4 page 19 1 Open furnace door 2 Using a 7 16 open end wrench remove three burner nuts Remove burne
9. CMF Series PO and PG Furnaces Service Manual Index Page iwc kA ec ee vest See ene geese 3 Electrical Supply amp Polarity 3 ale 4 Fam WUE TANS Si a ctl cheat data ha 4 Blower MO OT Ea 4 5 OI BUGT 5 Ol BUMD 5 6 Natural to EPCONVErSION E 6 Igniter Power Gas Only 7 Primary ee aia ha al oa 7 Cad aie cua 8 ignition Transformer neiseina abt nde cede oes volo 8 SUING 9 Combustion Air Band Reta eel tala tals 9 Air Housing Blower ct i aad 10 CBZ00A 10 Tro bleshooting Clans 11 15 SEVICE
10. Defective Nozzle Too Large or Incorrect Spray Pattern Temperature Too High Air in Oil Nozzle Too Pressure Pipe Far Behind Between Pump Combustion and Nozzle Head Ignition Electrodes Protrude Into Oil Spray Loose Fitting Nozzle Contaminated Nozzle Too Low Oil Pressure Cracked Nozzle Line or Adapter Too High Soot Oil Pressure Deposits Defective Pump Cut off Incorrect Positioning of Nozzle to Combustion Head Too High Oil Pressure Too Large Oil Nozzle Defective Clogged or Improperly Assembled Combustion Head Too Small Nozzle Bad Oil Cut off Upon Stop Start Too Low Oil Pressure Cold Air Entry Into Flue Pipe Faulty Test C02 Chimney Defective Pressure Regulating Pump Valve Leakage Between Nozzle and Fixture Flame Emits eae Too Low Oil Pressure NoSpark _ No Oil From Nozzle Defective Combustion Head Defective Nozzle Oil Viscosity Too High Short Varying Nozzle Circuit Output Worn Oil Pump Dirty Oil Filters in Pump or Nozzle Leaking or Dirty Suction Line Check Valve Defective Pump Coupling Defective Pressure Regulating Pump Valve Faulty Tank Empty Pump Rotation Wrong Low Pump Suction Transformer Cracked Insulator Layer of Soot or Oil Leak in Suction Line Loose Fitting Too High Vacuum Closed Valve on Suction Line or Installed Wr
11. Remove the regulator converter and its black cover located on top of the gas valve and invert See Figure 16 For LP the red ring will be located at the bottom and the LP stamping on the converter will appear right side up 2 Screwconverter back into the regulator hand tight plus 1 8 turn and replace the black cover onto the converter top to protect the threads Reassemble Appliance 1 Reassemble the burner assembly into the furnace 2 Reconnect the gas piping and electrical wires to the gas valve 3 Openthe manual shut off valve and follow the Operating Instructions as outlined previously in this manual to put the furnace into operation Centrifugal Switch The electric motor for the blower which supplies combustion air to the burner is equipped with a centrifugal switch wired in series with the burner controls This switch is normally open until the speed of the blower motor closes it thereby powering the burner controls The burner controls will not function until the blower motor is operating at full speed Firing Rate Conversion The rated firing rates of the CMF80 convertible furnaces PO amp PG can be adjusted from the factory setting of 75 000 BTU hr The firing rate can be changed to either 65 000 BT U hr or to 90 000 BTU hr using the appropriate certified NORDYNE conversion kit installed by a NORDYNE distributor or Ser vice PRO See the Replacement Parts Listing for the appro priate kit number
12. all reverse steps 1 7 Testing The Oil Burner See Figures 6 7 and 8 The two manual resets should be checked before testing any other CMF Furnace Component These are the Primary Control and the Burner Motor Manual reset Check the incoming power with a voltmeter Set the voltme ter at the proper scale a 120V 10 should be obtained If not check at power cord 1 Shut off power to the unit 2 Remove Electric Panel Cover 1 5 16 screw 3 Remove 2 wire nuts 4 Attach voltmeter to incoming power 5 Turn on power to the unit 6 Read voltage 120 10 7 Turn off power and reverse steps 1 3 Test Oil Pump The fuel s used in the oil gun pressure burner applications No 1 Fuel and No 2 Fuel Itis recommended to use 1 where temperatures fall below 32 The oil storage tank may be installed either above or below grade Check local or state codes To prevent abnormal tank pressure during fill the vent pipe should be 1 to 1 1 4 round On single line systems bleed all air out of the fuel supply system before lighting the furnace Test fuel pump resistance or vacuum with a vacuum gauge If vacuum reads greater than 10 inches look for kinked tubing a plugged oil filter undersized line excessive oil lift heavy oil or a frozen line Maximum Values for Vacuum Hq Single Stage Single Line M units 6 Single Stage Two Line M units 10 Two Stage 2 M units 15 The sec
13. bservation door on CMF series furnaces immediately after burner is placed in operation Yellow flame tips should be visible above combustion chamber 2 Burnershouldrun quietly Excessive updraft may cause burner to rumble rotate disc to decrease air supply CAUTION See Note below 3 Afterchecking the flame pattern and for noise level lock disc in position by tightening slotted head screw NOTE It is very important that air supply be ample without decreasing efficiency of burner An inadequate amount of air can cause carbon monoxide CO The carbon dioxide CO content of the flue products should be in the range of 8 0 to 9 0 percent for natural gas and 9 0 to 10 0 percent for LP gas Adjusting Heat Distribution 1 Set the room thermostat for the desired room temperature 2 Balance the heat distribution by adjusting the register openings LOCKING PGB Basic Air Shutter SCREW Settings To check combustion air openings Insert air guage vertically into the blower the gauge should stop within the range shown in the chart Make sure the Burner Model Air Setting shutter is securely PGB 1 G locked See Installation PGB 2 D Manual PGB 3 Figure 6 Air Shutter Adjustments for Power Gas Burner Air Supply for Sealed Combustion 1 Close and latch burner access door to complete the outdoor combustion air passage 2 Ifthe space below the home is enclosed be sure a vent or duct of at least 18 square i
14. ce or installing agency and in accordance with local maintenance can cause injury or property codes and ordinances Failure to properly install damage Refer to this manual For assistance or the furnace base assembly and venting system additional information consult a qualified as described herein may damage the equipment installer service agency or the gas supplier and or the home can create a fire or asphyxiation hazard violates U S listing requirements and will void the warranty This furnace is NOT approved for installation with split system air conditioning Use a NORDYNE packaged air conditioning system FOR YOUR SAFETY WHAT TO DO IF YOU SMELL GAS Do try to light any electrical switch do not use any phone in your building FOR YOUR SAFETY Immediately call your gas supplier from a neighbor s phone Follow gas supplier s instructions If you cannot reach your gas supplier call the fire department Do not store gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance Before installing the power gas burner removal of present burner is required See Figure 2 1 Shut off electric power supply to furnace Remove power cord from 120v receptacle remove low voltage thermostat wiring from primary control connections 2 Shut off fuel supply to burner close line or tank valve if applicable Disconnect fuel line at inlet
15. disconnected from furnace connections 3 Ifareadingotherthan above is read reverse conductors 3 NOTE If 120 volts 10 is not read check power source Door Switch See Figure 3 The door switch is a safety that will shut off 120 volt power to the furnace when the furnace door is open Itis a2 position switch 1 Open furnace door 2 Attach the voltmeter to the door switch 120 volt 10 should be read 3 Pushin onthe door switch the reading should go to zero volts Remove Door Switch Shut off power to furnace Disconnect 2 electric wires Press in at top and bottom of switch Remove door switch To reinstall reverse steps 1 to 4 above Fan and Limit Switch Combination See Figure 4 Testing the Limit Switch See Figure 5 When testing the limit switch with a voltmeter a 120V 10 reading indicates the switch is open and defective The limit switch should be replaced if cooled below switch setting 1 Turn off electrical power to the main power source Disconnect wires from limit switch located inside of control panel See wiring diagram located in control panel Figure 4 Figure 5 3 Using an ohmmeter connect leads to limit switch terminals 4 Iflimit switchis below temperature it will read continuity Ifthereis notcontinuity replace limit switch by removing two 1 4 screws Removing the Limit Switch 1 power off to the unit
16. e and to replace any part of the control system and any gas control which has been under water 5 Should overheating occur or the gas supply fail to shut off turn off the manual gas valve to the appliance Gas Control Lever Figure 5 Direct Ignition Gas Valve 20 OPERATING INSTRUCTIONS CMF PG Series with PGB DI Direct Ignition Burner 1 STOP Read the safety information above 2 Set the thermostat to OFF or to its lowest setting 3 Turn off all electric power to the appliance 4 This appliance is equipped with an ignition device which automatically lights the burner DO NOT try to light the burner by hand Turn the latch and open the furnace door Pushinthe gas control lever and move to OFF DO FORCE 7 Wait ten 10 minutes to clear out any gas If you then smell gas STOP Follow Section B in the safety information above If you don t smell gas go to the next step 8 Move the gas control lever to ON 9 Close the furnace door and turn the latch 10 Turn on all electric power to the appliance 11 Turnthe thermostat to ON and setto the desired setting 12 If the appliance will not operate after one re try follow the instructions in the To Turn Off Gas To Appliance Section below and call your service technician or gas supplier To Turn Off Gas to the Appliance 1 Set the thermostat to OFF or to its lowest setting 2 Turn off all electric power to the appl
17. eational vehicles and as acentral furnace special type when installed with model CB200A outlet Air base Standard Flue Furnaces The current line of furnaces using the standard flue system are the CMF series This is a heating only sealed combus tion furnace which draws its combustion air from under the home via a combustion air duct and vents the flue gases through the standard roof jack This furnace must be in stalled with the MA 100 or MA 200 base the SRu series roof jack and the vent pipe used in conjunction with the SRJ roof jack to meet U L requirements Figure 2 WARNING This furnace must be installed by a qualified installing agency and in accordance with local codes and ordinances Failure to properly install the furnace base assembly and venting system as described in the Installation Instructions may damage the equipment and or the home can create a fire or asphyxiation hazard violates U S Listing requirements and will void the warranty Testing the Electrical Polarity See Figure 3 1 See line voltage connections on unit wiring diagram in the back of this manual CAUTION Be careful to avoid electrical shock hazard 2 With power on at the fuse box test the line voltage conductors to the ground with a voltmeter set on the proper scale a L1 to ground should read 120 Volt AC 10 b Neutral to ground should read zero volts NOTE Testwith power on and conductors
18. for gas supply gas line valve on control lever on Check for burner safety lockout Restart burner Check for 24 volts to ignition control a No voltage at purge timer check the centrifugal switch in the combustion motor b No voltage to ignition control check purge timer allow one minute for purge timer to activate c Check for 120 volts to ignition control Voltmeter at L1 L2 16 Ignition control is powered 120v and 24v Ignitor does not heat up WARNING When replacing the ignition control replacement control MUST have the safety lockout time FAILURE TO FOLLOW THIS WARNING MAY RESULT IN AN EXPLOSION Always disconnect power before servicing Only persons trained and experienced in direct ignition systems should service this equipment If a condition exists that causes the ignition control to go into safety lockout meter readings must be taken quickly after restart within trial for ignition period Always de energize the system for atleast 45 seconds before recycling for further tests The ignition control cannot be repaired If the troubleshooting procedure indicates a malfunction in the control it must be replaced Remove AMP plug from burner tube receptacle and check for 120 volts at the plug during ignition sequence allow 3 minutes for ignition cycle Replace ignition control if 120 volts is not supplied to AMP plug within 3 minutes of ignition cycle
19. hut Down on Shut Down Good Good Defective Check Valve Ball Replace Pump Replace Replace Line Loose Return to Pump Restriction Connection 100 PSI Excessive Lift Service Guide For Furnaces with PGB Power Burner with Direct Ignition Burner motor does not run thermostat calls for heat 1 Defective thermostat circuit bridge TT connections on burner junction box if burner motor runs check a Thermostat connections b Thermostat No voltage to burner plug test lamp into burner plug receptacle if it does not light check for Blown fuse electric supply off Door switch not making contact Limit switch in open mode Check for clean air filter and proper airflow Loose wire connections Check for tripped manual reset auxiliary limit 2290p 120 volts is available to burner Testlamp does notlight Remove junction box cover on burner check for a Loose wires b Defective transformer c Defective motor Burner motor does not run no main flame 1 Defective centrifugal switch a Check the operation of centrifugal switch by removing end bell of the burner motor Ifthe contacts are accessible clean them c Ifthe contacts are accessible replace motor as on some burner motors the centrifugal switch cannot be replaced Burner in purge mode allow 3 minutes for burner to establish flame Check for proper electrical connections at purge timer control box or gas valve Check
20. iance if service is to be performed 3 Turn the latch and open the furnace door 4 Pushinthe gas control lever and move to OFF DO NOT FORCE 5 Close the furnace door and turn the latch Operating Sequence On a call for heat the thermostat contacts close which energizes the combustion blower motor When motor op eration reaches 80 of full rom the centrifugal switch located in the motor end cap closes A thirty 30 second pre purge cycle will occur before supplying power 24v to the gas valve When the ignition control is powered the ignition sequence is started with an internal safe start check After the safe start check is complete the control will initiate a timed ignitor warm up period During this time the ignitor is heated to ignition temperature When the warm up period is com pleted the control will open the gas valve for a timed trial ignition period The ignitor will light the gas and detect the presence of flame using the flame rectification principle If flame is detected the control will keep the gas valve open until the call for heatis completed If no flame is detected the control will close the gas valve at the end of the trial for ignition period The ignition control is equipped with a relight feature If the flame is extinguished during the run cycle the control will close the gas valve and repeat the ignition sequence as previously described Once in lockout the control can be reset by interrupting
21. l Loosen 1 8 Allen screw and remove wheel The wheel will be down 3 4 on the shaft 7 replace reverse steps 1 6 See Figure 9 6 and Figure 16 page 7 GN Installation Instructions CB 200A Base The model CB 200A 901696 base allows for anon sealed combustion central heating without warm air ducts instal lation of the CMF Series furnaces This installation must be done by a qualified installing agency in accordance with local codes and ordinances Location Allow clearance from adjacent materials as stated under Minimum Clearances Ample clearance should be pro vided to permit easy access for removal of filters blower motors controls and vent connections Unit must be installed in a level position on NORDYNE base model CB 200A Minimum Clearances To Adjacent Materials The furnace may be installed corner or against an open wall with the clearances not less than Front 36 inches Top 17 inches Vent 9 inches for oil units 6 inches for gas units 3 inches for rear and 2 inches for one side if in corner Rear clearance may 0 inches but vent clearance will be reduced to 6 inches Refer to table 8 appendix B of NFBA No 31 for requirements to achieve 6 inches vent clearance The minimum clearance from warm air register in base must be inches Use 15 5 8 L x 7 W sheet metal blank off panel to replace register when clearance is less than 36 inches Ve
22. n two or more appliances must vent into a common flue the area of the common flue should at least equal the area of the largest flue connector plus 50 of the area of the additional flue and vent connectors The flue or vent connector must be inserted into but not beyond the inside wall of the chimney flue liner Provisions must be made for adequate ventilation to prop erly support combustion and to maintain safe ambient tem peratures When buildings are so tight that normal infiltration does not meet air requirements one or more permanent openings must be provided to supply outside air The minimum cross section of the duct is to be 1 sq inch area free for each 2000 Btuh input for horizontal duct installations or 4000 input for vertical installations Refer to gas code book Installation Base The base must be located on a hard surface When the furnace location is carpeted use a hard surface platform under the base Furnace Set the furnace on the base without damaging the foam gasket material on the base top Making sure the furnace is seated on the back of the base fasten the front of the furnace to the base with 1 2 long sheet metal screws NOTE Front register is not adjustable and remains fully open Fuel line piping wiring and thermostat Refer to the instal lation and operation manuals provided with the furnace DANGER When using CB 200 A Cottage Base do not install the furnace in a mobile home Do
23. nches of free area is provided from the outside to provide sufficient air for combustion Make sure the combustion air duct extends through the floor and is unobstructed Gas Burner Controls Direct Ignition Series Combination Electric Gas Valve and Pressure Regulator The combination electric gas valve and pressure regulator performs several functions The gas valve control lever has two positions The OFF position completely shuts offthe gas supply The ON position allows gas flow through the redundant gas valve when it is energized electrically Gas to LP Conversion This gas fired heating appliance was shipped from the factory for use with natural gas However the appliance can be converted to be used with LP gas Use the following procedure for gas conversion of the burner Remove the Burner Assembly 1 Follow instructions To Turn Off Gas To Appliance 2 Shut off gas supply at meter 3 Disconnectgas burner electriccord gas piping to burner and thermostat leads 4 Remove three 3 hexagon nuts holding burner in place Change the Main Burner Orifice 1 Disconnect inlet pipe union at burner burner power cord 2 Disconnect the two wires leading to gas control valve 3 Remove three 3 bolts from U shaped manifold plate and orifice assembly 4 Remove the main orifice and replace it with the alternate fuel orifice supplied in the plastic bag with this burner Disconnect Change the Pressure Regulator 1
24. nd meter dial size of 1 cubic foot Burner Model PGB 1 PGB 2 BTUH Burner Time Per Input Orifice Rev 90 000 No 16 75 000 No 20 Table 1 Checking LP Gas Input LP gas installations are not usually supplied with meters for determining the amount of gas used The chart shows the approximate time required per dial revolution if a meter is used that is calibrated for cubic feet delivery The chart is based on LP gas at an average of 2 500 BTU per cubic foot burner manifold pressure of 10 W C and meter dial size of 1 cubic foot BTUH Burner Time Per Input Orifice Rev 90 000 98 75 000 117 40 47 PGB 1 PGB 2 No 36 No 40 Table 2 Adjusting the Burner 1 Air shutters are factory preset for installation a given furnace See Figure 15 Local conditions may require fine tuning Rotate the air shutter disc at the left of the burner housing to adjust the combustion air Rotate the disc counterclockwise to increase combustion air Rotate the disc clockwise to decrease combustion air The combustion air for the power gas burner is taken from the outside of the manufactured home Operating at high altitudes for operation at elevations of more than 2 000 feet above sea level the input should be de rated 4 for each 1 000 feet above sea level by reducing orifice size or decreasing the manifold pressure 1 Observe combustion flame through o
25. not install the furnace in a closet alcove or other enclosed area Violation of the above may cause incomplete combus tion which may produce poisonous gases causing as phyxiation and resulting in sickness or death LL Conduct Draft Test Adjust Draft Gauge Test at Hole in Flue Conduct Flue Gas Temperature Test Test at Hole in Flue to Zero Allow Thermostat Needle to Stabilize Dirty Heat Exchanger Calculate Net Stack Temperature Dirty Heat Defective Exchanger or Blocked Chimney Overfiring Furnace Less Than Baffles 025 WC Over 630 F Burnt Out in Heat Air Band Exchanger Adjustment Poor Combustion Chamber Excessive Draft Soot in Heat Exchanger Underfiring Furnace Too Short or Wrong Flue Testing Combustion Efficiency With Bacharach Test Kit Drill 1 4 Hole on Flue Turn T Stat to Highest Thermostat Setting Allow 5 Minutes of Operation Conduct CO2 Test Test at Hole in Flue Adjust Air Band for Highest CO2 Reading With 0 to 1 Trace Smoke Reading Within 10 1 2 to 11 Operate Unit 15 Minutes Before Final Adjustments Tighten Air Band Screws Under Firing Combustion Chamber Nozzle Too Small Air Leaks in Furnace Air Band Open Too Under Wide 10 1 2 Faulty Nozzle Operation Poor Combustion Chamber Air Band Adjustment Air Band Closed Too Much Dirty Fan or Air Handling Over 11 Parts Too Little
26. nting CB 200A Base Unit must be vented through a permanent chimney or 4 type L low temperature venting system oil units or 4 type BW venting system gas units selected and installed by the installer Check chimney for soot leaks obstructions and proper height If itis necessary to construct anew chimney local conditions such as necessary height draft and num ber of appliances served should be checked with local building codes Horizontal distances to an existing chimney should be as short as possible and the connecting pipe should slope upward to the chimney at not less than a 45 angle Total length of the sloping pipe must not exceed 6 feet 10 Barometric regulator oil units is to be installed at the vent connection of the furnace All flue pipe joints should be fastened with sheet metal screws for rigidity To prevent down draft the chimney should extend at least 2 above the peak of roof The internal area of the chimney should equal the area of the flue outlet on the furnace The chimney should have no obstructions or sharp bends where soot and other foreign matter can accumulate If inspection shows it to be obstructed the chimney should be cleaned The existing flue pipe should be cleaned or a new pipe shouldbe installed Connectthe flue pipe to the chimney with few elbows as possible Do not install hand dampers of any type It is desirable that the furnace flue serves no other appli ances However whe
27. o establish flame To check the CAD cell start the burner and unhook both cad leads from the FF terminals on the primary control After the burner lights jump the FF terminals to keep the burner running Measure the ohms resistance across the cad cell lead as it views the flame This shouldbe 1 600 ohms orless A preferred reading is 300 1000 ohms Next with the meter still connected to the cad cell leads turn the burner OFF The Figure 19 Figure 18 dark condition should give a reading of 100 000 ohms or infinity If the reading is lower let the refractory cool down or look for stray light that might be entering the burner through the air inlet or around the transformer base plate If the cad cell is not performing within these guidelines replace it Removing the Cad Cell ar Figures 17 and 18 Shut off power to the unit Remove wires from primary control Open ignition transformer Turn cad cell 1 2 turn in retainer and lift out To replace reverse steps 1 4 Testing Ignition Transformer See Figure 20 A WARNING In testing the ignition transformer extreme caution should be exercised because 10 000 to 14 000 volts are present The most common field test of the ignition transformation spark is using a service test cord connected to the primary winding wiring and an INSULATED screw driver The tests should indicate an arc 1 1 2 long ARC from the terminal post to the casing
28. ond fuel pump testis to check the pump efficiency or capacity With the burner running the efficiency is satisfactory if the oil pressure can be adjusted to 140 PSI After checks adjust the oil pressure for normal operation to 100 PSI Figure 7 Figure 8 Figure 9 The third fuel pump test is for cut off Start the burner and after a few moments of operation shut off the burner Upon shutdown pressure should drop approximately 15 to 20 PSI The two common reasons for inefficient cut off on fuel pumps are a defective check valve ball in the pump or poor connectors allowing air into the piping system Replacing Oil Pump See Figure 19 page 8 1 Shut off and disconnect power to the unit 2 Shut off oil to pump 3 Remove oil line 4 Using a 7 16 wrench loosen oil lines from pump open to drain assembly Remove oil lines from pump and move out of the way Remove 1 4 x 20 x 7 8 hex head screws with 3 8 open end 7 Pull pump out slowly 8 Toreplace reverse steps 1 7 When installing single line systems the only connections the burner fuel pump is at the intake port It is important not to install the by pass plug in the fuel pump return port A quick rule which can be used for checking an installation with the oil storage tank below the fuel pump is to figure 1 1 of vacuum for every 10 of horizontal run 2 1 of vacuum for every 1 of vertical lift 3 1 2 of
29. ong Direction Broken Seized Pump or Motor Coupling Faulty Pump Check Valve Suction and Return Lines Reversed 2 Line Pump on 1 Line System or Vice Versa Dirty Pump Filter Oil Line Clogged Dirty Nozzle Too High Viscosity Oil Crimped Line 13 vl Testing Faulty Fuel Delivery Gas vane Shut Off Valve Closed Improper Pressure Input Output Wrong Faulty Fuel FeUy of of Fuel Pump Clogged i Combustion Line Head amp Nozzle Line Restriction Too High Vacuum Empty Tank Excessive Lift 0 Valve Dirty Suction Kink Ete Restricted Combustion Closed Line Air Intake Check Valve Test Burner Motor Loose Supply Line 1 Sediment in Clogged Connections Defective Clogged Clogged or Supply Tank Oil Wrong Line Contaminated Pump Nozzle Filter Oil Strainer Faulty Installation Too Long Tubing Run Excessive Oil Lift Improper 2 Line Pump on By Pass Plug Suction and Shut Off Valve Venting of 1 Line System Installed in Return Lines Installed in Tank or Vice Versa Return Port Reversed Wrong Direction Undersized Tubing Testing Fuel Pump Check Perform Visual Check Efficiency Check Cut Off Resistance Or Capacity Inspection Bindin Shaft Over Less 6 Adjusts to Will Not 15 20 PSI Drop Over 20 PSI 8 Rounded 10 Vacuum Vacuum 140 PSI Adjust on S
30. r assembly from furnace 3 To replace burner reverse steps 1 amp 2 NOTE Be certain to install new gasket Remove Burner and or Ignitor Shut off gas supply Remove gas lines from Gas valve Unplug ignitor Remove 3 1 4 screws Lift burner up and out Remove 1 1 4 screw and replace ignitor Set gap distance between ignitor and burner head at 1 2 5 8 Micro amp signal should be between 2 to 4 micro amps DARN Figure 10 Figure 11 Figure 12 Remove Hot Surface Ignition Series See Figure 12 1 Shut off power to the furnace 2 Remove all wires 24 volt and 120 volt 3 Remove 2 1 4 screws 4 remount reverse steps 1 3 Removing C Burner Motor See Figure 4 page 19 Shut off power to the furnace Remove wires from HSI control Remove 4 1 4 screws and HSI control Remove 2 1 4 screws and panel cover Disconnect wires to motor 2 red and 2 black Dore a motor To reinstall reverse steps 1 6 N Figure 15 Figure 16 Figure 14 Removal of Air Housing Blower Wheel and Motor See Figures 14 16 Shut off power to unit Remove elect wires Remove 4 1 4 screws 2 on each side of air housing Remove band screw 5 16 bolt To replace reverse steps 1 4 The 3 circuits of the primary control see Figure 14 are the Starting Circuit Safety Circuit and the Running Circuit Tes
31. r s instructions If you cannot reach your gas supplier call the fire department Should overheating occur or the gas supply fail to shut off disconnect the power at the main circuit breaker and then see To Turn Off Gas Appliance 19 Operation CMF PG Series FOR YOUR SAFETY READ BEFORE LIGHTING OR OPERATING WARNING If you do not follow these instructions exactly a fire or explosion may result causing property damage personal injury or loss of life 1 This appliance does not have a pilot It is equipped with an ignition device which automatically lights the burner Do not try to light the burner by hand 2 BEFORELIGHTINGOROPERATING smellall around the appliance area for gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor WHAT TO DO IF YOU SMELL GAS Do not to light any appliance Do not touch any electric switch do not use the phone Leave the building immediately then call your gas supplier If you cannot reach the gas supplier call the fire department 3 Use only your hand to push in and move the gas control lever Never use tools If the lever will not push in by hand don t try to repair it call a qualified service technician Force or attempted repair may resultin afire or explosion 4 Do not use this appliance if any part has been under water Immediately call a qualified service technician to inspect the applianc
32. spray pattern and metering the fuel See Figure 22 Several precautions should be observed when installing an oil nozzle See Figure 22 Do not clean a dirty nozzle replace it Do not bump nozzle with a wrench Do not touch nozzle with your fingers Install nozzle with a nozzle wrench Be sure strainer is in place and tight Do not over tighten nozzle during installation Low Burner Pressure and Poor Combustion A flex coupler can contribute to low burner pressure and poor combustion if the following occurs 1 coupler is too long and causes high amperage burner motor reading 2 The coupler is worn and slipping 3 The fuel pump shaft is worn and rounded causing the coupler to slip See Figure 23 The proper mixture of fuel and air is delivered to the burner through an air adjustment band located on the burner housing See Figure 24 The primary purpose of the combustion chamber liner is to isolate the combustion process from the rest of the furnace and prevent damage to the components and the cabinet Removing Combustion Air Adjustment Band 1 Remove oil pump See oil pump replacement 2 Remove 2 5 16 screws from air band 3 Loosen 1 5 6 screw and remove band housing 4 To replace reverse steps 1 3 Figure 24 Removing Motor and Blower Wheel Shut off power to the unit Open transformer Remove motor wire Remove 2 3 8 screws Remove motor and blower whee
33. tch is open With the door open secure the door switch in the closed position by depressing the switch The means for securing the door switch must be removed once this testing has been com pleted 1 Disconnect the thermostat wires from TT connections onthe burner junction box Ifthe burner shuts off check for a Short circuit in the thermostat wires b Defective thermostat Burner flame without motor running Gas valve is stuck in open position Replace the control burner and heat exchanger may need cleaning Noisy fire Readjust combustion air to reduce volume of air being drawn into the burner Caution See burner adjustment High Gas Bills 1 Check the combustion air adjustment 2 Be sure the proper size orifice is being used 3 sure the return air filter is clean 4 sure the home is insulated windows and doors fit tightly and there are no air leaks in the heating ducts 5 Check room thermostat to be sure the setting is not higher than necessary Low humidity requires higher temperatures for comfort Perhaps humidity should be increased Circulation blower will not operate even though the burner operates 1 Turn onthe manualblower switch If the blower operates check the fan switch 2 Check the wiring to the motor 3 Check for a burned out motor CMF Oil to Gas Conversion WARNING WARNING This furnace must be installed by a qualified Improper installation alteration servi
34. the 24 VAC power This can be easily accomplished by setting the thermostat below room tem perature for at least forty five 45 seconds and then return ing it to desired setting If adjusting the thermostat does not reset the ignition control turn power to the appliance off for forty five 45 seconds and then turn it back on NOTE If the gas control has been replaced or serviced lighting may not be satisfactory until air has been purged from the gas line or the gas input and combustion air have been adjusted Checking Natural Gas Input Check the label on the burner to be sure the burner is equipped with orifices for type of gas being used Alternate orifices are in bag attached to the burner Instructions for changing orifices are covered later herein To check the input time the dial on the meter for one revolution while the burner is operating Be sure to isolate all other gas consuming appliances except pilots If the time varies more than 5 from the times shown on the chart check the gas pressure according to the procedure stated in GAS BURNER CONTROLS If the pressure reading matches the pressure shown on the chart check to be sure the proper burner orifice is being used Further gas prob lems shouldbe referred to the local gas supplier Natural gas varies in BTU value from 950 to 1 050 BTU per cubic foot The chart is based on natural gas at an average of 1 000 BTU per cubic foot burner manifold pressure of 3 5 W C a
35. ting the Primary Control Circuits 1 Shut off power to the unit Close off oil supply Remove 1 5 8 screw from housing strap and lift off 2 Remove thermostat wires from T1 and T2 and cad cell wires from F1 and F2 3 Turn power to the unit 4 Jumper out terminals T1 and T2 to test the starting circuit The burner should come on and then shut down after 45 seconds as the safety circuit engages Figure 17 5 Remove jumper wires and allow two minutes for the safety heater to cool off 6 Test running circuit by jumpering out T1 and T2 and reset the primary control The burner will come on 7 Immediately jumper F1 and F2 to bypass the cad cell The burner should run continuously after 45 seconds with the cad cell safety circuit by passed 8 Shut off power to the unit remove all jumpers and then reconnect the thermostat and cad cell 9 Ifany one ofthese test fails replace the primary control Removing the Primary Control 1 Shut off power to the unit 2 Open ignition transformer by removing 2 5 16 screws 3 Remove the black white and orange wires leading from the primary control 4 Remove cad cell wires from F1 and F2 and remove thermostat wires from T1 and T2 5 Loosen 2 1 4 screws and remove primary control 6 Toreplace reverse steps 1 5 Testing Cad Cell The cad cell is a light sensing resistor Its function is to cut power to the burner motor in the event the electrodes fail t
36. to order lt Natural Gas Configuration Figure 7 Natural Gas Configuration Ez sey lt LINE CORD TERMINAL HOUSING TERMINAL BOARD a 5 BUSHING IGNITOR CONTROL MODULE GAS VALVE CLOSED END CONNECTOR BUSHING TO COMBUSTION MOTOR BUSHING JO GOL s y paijddns asim y Aue MS jenueyy xog YOUMS Om _ Joywoedey JOJO 5 995 au 5 UMOUS paeeds CMF Wiring Diagram 067A 0298 11 98 Specifications and illustrations subject to change without notice and without incurring obligations Printed in U S A NORDYNE St Louis MO
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