Smith's RV Centre

Problem

Possible Cause

Correction

Pilot will not light

Empty LP-gas supply
Wrong LP-gas pressure

Defective piezo lighter
Incorrect spark gap
Clogged pilot orifice
Air in gas line
Adjustment screw wrong

Replenish
Adjust to 11 inches water-column
pressure
Replace lighted assembly
Set spark gap
Clean or replace
Purge gas line
Adjust pilot screw

Pilot will not stay lit

Defective thermocouple
Air leakage
Lack of air
Leaking control valve
Incorrect gas pressure

Clogged pilot orifice
Pilot-adjustment screw

Replace thermocouple
Check for leakage
Check for venting
Check control valve
Set to 11 inches water-coloumn
pressure
Clean or replace orifice
Adjust pilot-flame level

Noisy operation

Low input voltage
Unbalanced blower wheel
Loose blower wheel
Loud burner
Rubbing blower wheel

Charge or replace battery
Replace blower wheel
Tighten wheel
Adjust air shutter
Check clearance with housing

Main burner will not light

Thermostat off
Thermostat contacts open
Gas open
Empty propane tank
Low gas level in tank
Low gas pressure

Low battery voltage
Stuck sail switch
Defective sail switch
Defective limit switch
Reversed battery polarity
Blocked ducting
Blocked air intake
Blocked burned exhaust
No igniter spark
Incorrect spark gap
Dirty module connections
Clogged main burner jet

Turn on thermostat
Reset thermostat
Turn on gas supply
Replenish supply
Refill tank
Adjust 11 inches water-column
pressure
Charge battery
Clean switch
Replace switch
Replace limit switch
Check wiring
Check duct hoses
Check air intake
Clear burner exhaust
Check electrode lead
Reset spark gap
Clean connections
Replace or clean jet

Burner lights but shuts off (lockout)

Misaligned flame sensor
Loose sensor wire
Dirty sensor probe
Defective sensor
Defective module board
Low gas pressure

Low gas level in tank

Adjust flame sensor
Tighten connections
Clean probes
Test sensor
Replace board
Set to 11 inches water-colomn
pressure
Refill Tank

Main burner will not shut off

High thermostat setting
Stuck thermostat points
Defective gas valve

Reduce temperature setting
Replace relay
Replace gas valve

Blower will not run

No or low voltage
Blown 12-volt DC fuse
Reversed battery polarity
Open thermostat points
Locked motor
Defective motor relay
Defective motor

Check voltage at furnace
Check fuse, replace if necessary
Check wire connections
Check points for closing
Rotate by hand to check
Replace relay
Replace motor

No igniter spark

Improper input polarity
No voltage present
Poor electrode ground
Corroded connections
Loose connections
Wrong spark gap
Broken electrode lead
Cracked insulators
Faulty module board

Check 12-volt wiring
Check voltage at furnace
Check ground connection
Clean connections
Tighten connections
Set spark gap
Replace electrode lead
Replace insulators
Replace module board