December, 2003 SERVICE DIAGNOSIS Modine …

1 december , 2003 SERVICE DIAGNOSISM odine heating & ventilating problem / remedy Guide forModine:Gas-Fired Unit HeatersGas-Fired Duct FurnacesSteam/Hot Water Unit HeatersElectric Unit HeatersOil-FIred Unit HeatersInfra-Red HeatersThe Modine SERVICE DIAGNOSIS Guide was compiled as atrouble shooting guide intended to define the most commontypes of SERVICE problems found with heating equipment, thepossible causes of these problems, and possible remedies. Thistrouble shooting guide, used in conjunction with the appropriateproduct Installation and SERVICE Manual, should enable aserviceperson to identify, investigate and resolve most fieldservice problems found with industrial/commercial unit :When servicing any unit heater locate the rating plate andrecord the model number, power code number, control codenumber, and serial number shown. This information is requiredto identify components and date of a SERVICE problem is encountered which can not be resolvedwith the use of this SERVICE guide, and the appropriateinstallation and SERVICE manual, further assistance can beobtained by contacting your local Modine factory PageA.

2 UNIT WILL NOT OPERATE ..3 All UnitsGas-Fired UnitsOil-Fired UnitsElectric UnitsB. PILOT WILL NOT LIGHT OR STAY LIT ..3 Gas-Fired UnitsDuct FurnacesInfra-Red HeatersC. PILOT FLAME NOT NORMAL ..4 Gas-Fired UnitsInfra-Red HeatersD. BURNER WILL NOT LIGHT OR STAY LIT ..4, 5 Gas-Fired UnitsInfra-Red HeatersOil-Fired UnitsE. BURNER FLAME IS NOT NORMAL ..5, 6 Gas-Fired UnitsInfra-Red HeatersOil-Fired WILL NOT SHUT-OFF ..6 All UnitsGas-Fired UnitsInfra-Red HeatersG. BURNER SHUTS OFF TOO SOON ..6 All UnitsH. CONTROL FAILURE ..6, 7, 8, 9 Gas-Fired UnitsInfra-Red FAILURE .. 9, 10 All OPERATES BUT BURNER DOES NOT OPERATE ..10 Gas-Fired UnitsOil-Fired UnitsK. BURNER OPERATES BUT FAN WILL NOT OPERATE ..10 Gas-Fired UnitsOil-Fired UnitsL. BURNER MOTOR DOES NOT START ..10 Oil-Fired UnitsM. BURNER MOTOR OPERATES BUT NO OILDELIVERED AT NOZZLE ..11 Oil-Fired UnitsN. BURNER MOTOR OPERATES, DELIVERS OIL,BUT NOT FLAME ..11 Oil-Fired UnitsPROBLEMSee GAS OR NO OIL.

3 11, 12 Gas-Fired UnitsOil-Fired UnitsQ. OIL LEAK OR GAS LEAK ..12 Gas-Fired UnitsOil-Fired UnitsR. INSUFFICIENT HEAT ..12, 13 All UnitsGas-Fired UnitsElectric UnitsSteam/Hot Water UnitsS. TOO MUCH HEAT ..13 All UnitsGas-Fired ODORS ..13 Gas-Fired UnitsOil-Fired UnitsU. NOISY OPERATION ..14 All UnitsGas-Fired UnitsOil-Fired PRESSURE ..14 Gas-Fired UnitsOil-Fired UnitsW. LOW OIL OR GAS PRESSURE ..14 Gas-Fired UnitsOil-Fired UnitsX. NOISE OF IGNITION OR EXTINCTION ..15 Gas-Fired UnitsOil-Fired PROBLEMS ..15 Gas-Fired UnitsInfra-Red HeatersZ. HEAT EXCHANGER FAILURE ..15, 16 Gas-Fired UnitsOil-Fired UnitsSteam/Hot Water UnitsAA. UNIT CYCLES ON OVERHEAT ..16, 17 All UnitsBB. CORROSIVE DAMAGE ..17 Gas-Fired UnitsOil-Fired UnitsSteam/Hot Water UnitsCC. THERMOSTAT PROBLEMS ..17, 18 All UnitsTABLE OF CONTENTS3 ProblemPossible CausePossible RemedyA. Unit Will Not circuit in on power, turn up thermostat, fuse(s) and reset or or adjust or wiring and connections.

4 If unit according to Modine wiring or controls and replace if Control Failure, pages, 6, 7, 8, Motor Failure, pages 9. manual gas main manual valve or replaceinoperable or in closeddefective light oil tank, or open supply valve, or check control locked reset button on primary control onlyon heat exchanger is cool. Try this only control SERVICE instructions inInstallation cad cad cell if necessary. Check or fan motor voltage, wiring and motor. Reseton button on burner motor. Fan motorautomatically Unit fuses. Check for cause of blown or burned secondary voltage with if Pilot Will Not Light valve inoperative pilot valve or replace defectiveStay Litin closed Units, pilot reset button to manufacturer s lighting instructionsDuct Furnaces andplunger not depressedon serial plate and relight pilot. ReplaceInfra-Red Heaterscorrectly or safety pilotsafety pilot line or orifice or flame too low pilot per manufacturer stoo in pilot air from pilot line as per manufacturer draft blowing move or shield unit from away from or dirty or clean connections.

5 Replacecouple connections ordefective being blown Burner Flame is Not Normal, pages 5, excessive gasremains in burner onignition or extinctioncausing Flame impinging on cold10. Tighten all pilot tube of thermocouplefrom loose pilot CausePossible RemedyC. Pilot Flame is Not Normal1. Lazy yellow orifice too orifice Waving blue draft at move or shield unit from Small blue gas gas pressure and adjust as permanufacturer s Flame being lifted pressure too gas pressure and adjust as perpilot burnermanufacturer s Hard sharp orifice too orifice Burner Will Not circuit in on power, turn up thermostat, oror Stay Litopen fuse(s) and reset disconnect Units manual gas valve or replace defective Heatersclosed or or wiring and connections. If unit according to proper wiring flame too pilot per manufacturer or controls and replace if Control Failure, pages 6, 7, 8, draft or shield unit from away or dirty or clean thermocouple connections orReplace defective thermocouple if or Excessive primary Adjust primary air per manufacturer s recommendations.

6 See Installation Carry-over ports on11. Clean and replace if plugged. Lint orspider webs in venturitubes or bugs orobstructions in mainburner Improper pilot Reposition Mis-aligned Align burner with main burner Low gas Check gas pressure and adjust as permanufacturer s Unit Installed with pilot15. Reinstall unit with pilot on high side as peron low side of unitsmanufacturer s on an angle(infra-red only).16. Low pilot gas pressure16. Check pilot gas pressure and adjust toon milli-volt controlrecommended water for infra-red CausePossible RemedyD. Burner Will Not motor electrode spacing or replace ignitionor Stay Lit (continued)but no control reset button on primary control onlyout on heat exchanger is cool. Try this only Control SERVICE Instructions in Installation cad cad cell if necessary. Check or fan motor voltage, wiring and motor. Reseton button on burner motor. Fan motorautomatically nozzle. Use only exact Installation Manual for size and leaks in suction all Reset electrodes in burner Check wiring at primary Replace ignition transformer, if Check for proper contact betweentransformer springs and electrode bus draft, too much draft regulator adjustment.

7 Adjustcombustion air openings on oil fuel pump using pressure gauge forproper Burner Flame is Not NormalGas-Fired Units1. Long yellow tipped Lack of combustion air1a. Provide proper combustion Insufficient primary Increase primary air by adjusting primaryair shutters back, or adjusting burnermanifold Main burner orifices1c. Check main burner orifice size againstincorrectly s recommended Clogged burner ports,1d. Clean or replace burner if Mis-aligned main burner1e. Re-align orifices with (s).1f. Vent Clean vent Flames lifting from Excessive gas Check gas pressure and adjust permanufacturer s Main burner orifices2b. Check main burner orifices size againstincorrectly s Defective Replace Flame Excessive Move unit or shield unit so flames will notbe affected by Defective Replace Flashback at4a. Ports of burner too Repair or replace of burner Excessive primary Reduce primary air by moving primary airshutters forward, or adjusting burnermanifold Flashback on primary primary air by moving primary CausePossible RemedyE.

8 Burner Flame is Not Normal(continued)Infra-Red Heaters1. Gas burning at Loose screws holding1a. Tighten mounting Cracked Replace Loose or missing seal in1c. Inspect and replace if mounting framesor under ceramicsmounting Warped burner or ceramic1d. Burner color appears2a. Low gas Check gas pressure and adjust as perdull red, not s Mis-aligned main2b. Re-align burner Incorrectly sized main2c. Check main burner orifice size againstburner s recommended combustion start-up procedure in Installation draft regulator. See Installation atomization of nozzle with same type and nozzle with same type and Will Not Shut wired wiring and rewire if set too wire circuit in wiring and out of or or Units under gas valve gas off gas at manual valve. Check linepressure to gas controls and adjust permanufacturer s recommendation. Replacegas Burner Shuts Off Too out of or replace Unitscalibration or is cycling on Unit Cycles on Overheat, 16, overheat Control FailureGas-Fired UnitsStanding Pilot Systems1.

9 Pilot Will Not Light or1a. Defective Check and replace if Dirty thermocouple1b. Inoperative magnetic1c. valve Gas valve turned to off1d. Turn to pilot Condensate in pilot Inoperative pressuresensing switch (power vented models only).aa. Defective Replace Vacuum leaks atbb. Seal venter Excessive staticcc. Check venting for compliance withpressure in vent s CausePossible Remedy1. Pilot Will Not Light ordd. Unit over Adjust to proper Lit (continued).ee. Negative pressureee. Correct building negative in drive not air blower per manufacturer scorrectly; blower too Main Burner Will Not Defective electric Gas valve turned to OFF2b. Turn to ON PILOT Unit mis-wired or loose2c. Check all connections and rewire if Loose connections on2d. Check wiring. Replace limit control if control or defective limit Defective or plugged2e. Inspect gas valve regulator. Replace if gas valve Defective thermostat or2f.

10 Calibrate thermostat or replace if out of Thermostat heat2g. Check anticipator setting and correct if incorrectly set(low voltage controls).2h. Power venter centrifugal2h. Check centrifugal switch if unit is supplied withswitch not closing ora power venter. Check wiring. Check powerwired On units equipped with2i. If fuse if blown, replace fuse and determineenergy cut-off (ECO)reason for blown fuse. The ECO is an overdevice fuse in energyheat protection control and the cause ofcut-off may be blownoverheating must be corrected beforeor the equipment back into SERVICE .(See Section AA ).Gas-Fired UnitsIntermittent PilotIgnition Systems1. Pilot Will Not Light1a. No spark at Check connections. Check for proper sparkor Stay , cracked or broken electrode ceramic,blown controller fuse or brittle, cracked orloose high tension Defective flame sensor1b. Check mili-amps of sensor. Tighten looseor loose connections toconnections. Replace flame sensor if Pilot valve electrical 1c.