When making the fuel pressure check, be sure fuel is flowing through the nozzle. The fuel regulator can be adjusted.  Turn the adjusting screw clockwise to increase feel pressure and counterclockwise to decrease it. (Refer to Figure 21-4.)
Restriction in fuel nozzle
Remove the nozzle and clean orifice.
or replace it.
Suction leak ahead of pump.
Secure all fittings.
Fuel heater solenoid not
Remove and check solenoid. operating.
Replace if faulty.
Insufficient fuel pressure.
Low or no current to fuel pump. Check operation of pump.
Fuel lines clogged or broken.
Inspect all lines and connections. It may be necessary to disconnect lines at various points to determine where the restriction is located.
Ignition vibrator inoperative.
Replace vibrator.
Regulator not operating properly.
Check for low pressure or replace regulator.
Manual reset limit (overheat)
Press reset button firmly (overheat switch open.
light will illuminate when heater switch is on) and recheck to determine reason for switch opening.
21-00-00 Page 21-8 Revised: February 28, 2002
1H6
CHART 2101.  TROUBLESHOOTING (JANITROL HEATER) (cont)
Trouble  Cause  Remedy 
Heater fails to light. (cont)  Combustion air pressure switch open. (Defective switch or low combustion air blower output.) Cycling switch open. Duct switch open.  Check for low blower output due to low voltage and correct it. If switch is defective, replace it. Replace if defective. Operate control to see if switch will come on. Replace switch if defective. 
Ventilating air blower fails to run.  Heater switch “OFF.” Broken or loose wiring to motor. Circuit breaker open. Worn motor brushes. Blower wheel jammed. Motor burned out. Defective radio-noise filter.  Energize the heater switch. Check and repair wiring. Close circuit breaker. Replace motor brushes. Remove and check the ventilating air blower wheel and realign if necessary. Remove blower assembly and replace motor. Replace filter. 
Combustion air blower fails to run.  Faulty wiring to motor. Poor ground connection. Worn motor brushes. Blower wheel jammed. (Usually indicated by hot motor housing.) Defective radio-noise filter. Faulty or burned out motor.  Inspect and replace faulty wiring. Tighten ground screw.  Be sure any metal preservation has been removed for good ground connection. Replace motor brushes. Overhaul the combustion air blower. Replace filter. Remove combustion air motor for overhaul or replacement of motor. 

21-00-00 Page 21-9 Revised: February 28, 2002
CHART 2101.  TROUBLESHOOTING (JANITROL HEATER) (cont)
Trouble  Cause  Remedy 
Heater fires but burns unsteadily.  Insufficient fuel supply.  Inspect fuel supply to heater, including shutoff valve, solenoid valve fuel pump and fuel lines. Make necessary repairs. 
— CAUTION — 

DO NOT CREATE A SPARK GAP BY HOLDING THE LEAD TO THE HEATER JACKET.  THIS CAN RESULT IN DAMAGE TO THE LEAD AND IGNITION UNIT AND THE OPERATOR MAY RECEIVE AN ELECTRICAL SHOCK.
Spark plug partially fouled.
Replace spark plug.
Loose primary connection
Tighten the connection. at ignition assembly.
Faulty vibrator.
Replace the vibrator.
Combustion air blower speed
Remove and overhaul the fluctuates. (Can be caused by
combustion air blower assembly low voltage, loose blower
as required or correct low wheel, worn brushes or motor.)
voltage condition.
High voltage leak in lead
Replace ignition assembly. between ignition assembly and spark plug.
Inoperative ignition
If vibrator is in good condition, assembly.
replace ignition assembly only.
Restriction in fuel nozzle
Remove nozzle for cleaning orifice.
or replacement.
Nozzle loose in retainer or
Tighten or replace the nozzle improper spray angle.
as required.
Heater starts then goes out.
Lack of fuel at heater.
Check fuel supply through all components from the tank to the heater.  Make necessary corrections.
21-00-00 Page 21-10 Revised: February 28, 2002
1H8
CHART 2101.  TROUBLESHOOTING (JANITROL HEATER) (cont)
Trouble  Cause  Remedy 
Heater starts then goes out, (cont)  Inoperative or chattering combustion air pressure switch. Inoperative overheat switch. Inoperative cycling switch. Low voltage.  Adjust or replace switch. Replace switch. Adjust or replace the switch. Attach external power. 
Heater fails to shut off.  Fuel solenoid valve in heater stuck open. Inoperative duct and cycling switch. Defective heater switch.  Remove and replace solenoid assembly. Check and repair. Replace the heater switch. 
　
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