Nortek CMF PG Series, Service Manual

Page 1: ...CMF Series Service Manual PO and PG Furnaces ...

Page 2: ...low Charts 11 15 Service Guide 16 17 Oil to Gas Conversion 18 22 Wiring Diagrams 23 24 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 Performingservice as outlined in this service manual will require theuse of calibratedtest instruments Using uncalibra...

Page 3: ...ce 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 stalledwiththeMA 100orMA 200base theSRJseriesroof jack and the vent pipe used in conjunction with the SRJ roof jack to meet U L requirements Figure 1 Figure 2 Testing the Electrical Polarity See Figure 3 1 See line voltage connections on un...

Page 4: ...ontinuity Ifthereisnotcontinuity replacelimitswitchbyremoving two 1 4 screws Removing the Limit Switch 1 Turn power off to the unit 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 Thestepsnecessarytochecktheoperationo...

Page 5: ... The fuel s used in the oil gun pressure burner applications are No 1 Fuel and No 2 Fuel It is recommended to use 1 where temperatures fall below 32 The oil storage tank may be installed either above or below grade Checklocalorstatecodes Topreventabnormaltank pressureduringfill theventpipeshouldbe1 to11 4 round On single line systems bleed all air out of the fuel supply system before lighting the ...

Page 6: ... vacuum requirements the following will occur 1 Asolidcolumnofoilwillnotbedeliveredtotheatomizing 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 Figure 9 Figure 10 WARNING Before beginning conversion shut off elec tricalpowertothefurnaceatthemainpower source Shut off gas supply 1 Disconnection a Low voltage wires b ...

Page 7: ...F2 3 Turn on 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 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 To remount reverse steps 1 3 Removing C Burner Motor See Figure 4 page...

Page 8: ...inals 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 leadasitviewstheflame Thisshouldbe1 600ohmsorless A preferred reading is 300 1000 ohms Next with the meter stillconnectedtothecadcellleads turntheburnerOFF The dark condition should give a reading of 100 000 ohms or infinity If the reading is lower l...

Page 9: ...lacement 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 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 readingindicatesa defectivetransformer A10 000volt voltmeterisrecommendedtotesttheignitiontransformer spark 3 1 long...

Page 10: ...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...

Page 11: ...r Poor Combustion Chamber Poor Combustion Chamber Excessive Draft No Smoke on Disc CO2 Low Under 10 1 2 CO2 High Over 11 Under Firing Combustion Chamber Nozzle Too Small Air Leaks in Furnace Air Band Open Too Wide Air Band Adjustment Tighten Air Band Screws Air Band Closed Too Much Dirty Fan or Air Handling Parts Underfiring Furnace Turn T Stat to Highest Thermostat Setting Allow 5 Minutes of Oper...

Page 12: ...esign with Solid Cone Nozzle Air Restriction Wrong Nozzle Improperly Located Electrodes Nozzle Installed Too Far Forward Oil Center Fire Clogged Nozzle Improper Drawer Assembly Adjustment Air Shutter Opening Too Wide Some Models Too Large Nozzle Capacity Mismatched Spray Atomizing Pattern Combustion Head Assembled or Located Improperly Oil Pressure Too Low Too Small Spray Angle Flue Obstruction Im...

Page 13: ... Restriction Layer of Soot or Oil Tank Empty Pump Rotation Wrong Low Pump Suction Faulty Fire Valve Too Low Oil Pressure Too Small Nozzle Cold Air Entry Into Flue Pipe Test CO2 Cracked Nozzle Line or Adapter No Spark No Oil From Nozzle Too High Oil Pressure Incorrect Positioning of Nozzle to Combustion Head Bad Oil Cut off Upon Stop Start Defective Clogged or Improperly Assembled Combustion Head T...

Page 14: ...gged or Wrong Nozzle Kinked Tubing Wrong Orifice Clogged Orifice Shut Off Valve Closed Defective Gas Valve Improper Pressure Input Output Restricted Combustion Air Intake Crack Loose Fitting Too High Vacuum Excessive Lift Restriction Kink Etc Shut Off Valve Installed in Wrong Direction 2 Line Pump on 1 Line System or Vice Versa Improper Venting of Tank Undersized Tubing Too Long Tubing Run Excessi...

Page 15: ... Rounded Binding Replace Pump Line Restriction Check Cut Off Less 6 Vacuum Over 10 Vacuum Loose Connection Return to 100 PSI Will Not Adjust Adjusts to 140 PSI Good Replace Defective Check Valve Ball Replace Pump Over 20 PSI on Shut Down 15 20 PSI Drop on Shut Down Good Air in System Excessive Lift ...

Page 16: ...nition control Voltmeter at L1 and L2 1 Remove AMP plug from burner tube receptacle and check for 120 volts at the plug during ignition sequence allow 3 minutes for ignition cycle 2 Replace ignition control if 120 volts is not supplied to AMP plug within 3 minutes of ignition cycle start 120 volts is available at AMP plug Ignitor does not heat up 1 Disconnect burner plug from furnace receptacle 2 ...

Page 17: ...ed 1 Disconnect the thermostat wires from TT connections on the burner junction box If the 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 Readjustcombustionairtoreducevolumeofairbeingdrawn into the burner Cautio...

Page 18: ...hut off fuel supply to burner close line or tank valve if applicable Disconnect fuel line at inlet 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 theheatexchangershouldbecleanedtoinsure proper draft Installing Gas Burner 1...

Page 19: ... s phone Follow the gas supplier 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 poweratthemaincircuitbreakerandthensee To Turn Off Gas Appliance WARNING Figure 2 120V Receptacle Primary Control Power Cord Fuel Line Fitting HSI Control Power Cord Thermostat Connections Figure 3 Mounting Studs B...

Page 20: ...t the burner by hand 5 Turn the latch and open the furnace door 6 PushinthegascontrolleverandmovetoOFF DONOT 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 applian...

Page 21: ...ion air Rotate the disccounterclockwisetoincreasecombustionair 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 o...

Page 22: ...s 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 twopositions TheOFFpositioncompletelyshutsoffthegas supply The ON position allows gas flow through the redundant gas valve when it is energized electrically Gas to LP Conv...

Page 23: ...CTRICAL BOX GAS VALVE IGNITOR LINE CORD CLOSED END CONNECTOR BLACK BLACK GREEN BLUE BLUE BLACK WHITE RED RED RED BLACK GROUND SCREW BLACK BLACK 120V 24V RED RED BLACK BLACK BLACK BLUE YELLOW YELLOW WHITE GV PSO FSG C IND L1 HSI HSIG L2 W PSI FSI CONTROL MODULE TERMINAL HOUSING TO COMBUSTION MOTOR ...

Page 24: ...120V N L1 G Aux Limit Blk Blk L1 120V G N 1 2 3 4 5 6 1 2 3 4 5 6 1 1 1 1 Blue Red Blower Motor Wht Wht Blk Red Blue Blk Wht Wht Blk Red Blower Wire Color Blower Speed Blue Black Low Med High Represents Control Box Blk Brn Brn Blower Motor Capacitor CMF Wiring Diagram 067A 0298 Specifications and illustrations subject to change without notice and without incurring obligations Printed in U S A 11 9...