1018028-A
Page 17
SYMPTOM
POSSIBLE CAUSES
TROUBLESHOOTING CHART
( For Qualified Service Technician
)
-
MAIN BURNER
1. Gas leak.
1. Main gas off.
2. Thermostat not set high enough to
call for heat.
3. Clogged burner orifice.
4. Thermostat wired wrong or
defective.
Gas Odor
Failure
to Ignite
CORRECTIVE ACTION
Flame Too
Large
1. Defective operator section of valve.
2. Burner orifice too large.
3. If installed above 2,000 feet.
1. Replace valve.
2. Check with local gas company for proper orifice size and replace.
3. See orifice chart, (
Fig. 10 on page 12).
1. Clogged burner ports.
2. Obstructions around vent cap.
Yellow Burner
Flame
1. Remove main burner and check for obstructions in throat, ports, and orifices. Clean - but do
not enlarge ports or orifices.
2. Make sure area around vent cap is clear, be sure vent system is sealed.
1. See
page 1.
1. Pilot flame too small.
2. Burner ports clogged at pilot.
3. Low gas pressure.
4. Pilot decreases in size when main
burners come on.
Delayed
Ignition
1. Adjust pilot flame.
2. Clean burner ports (do not enlarge).
3. Check gas supply pressure.
4. Supply piping is too small. Consult local gas company or competent installer.
1. Open all manual gas valves.
2. Set thermostat to higher temperature.
3. Clean burner orifice (do not enlarge).
4. Check wiring, jump across thermostat terminals at valve, if valve open, re-check wires,
replace thermostat.
1. Defective or damaged
thermostat wire, or thermostat.
2. Thermostat location.
3. Defective or sticking valve.
4. Excessive gas pressure.
Burner Won’t
Turn Off
1. Can be checked by removing wire from valve terminal. If valve goes off, replace wire
or thermostat.
2. Follow instructions, check location.
3. Replace valve.
4. Contact utility supplying gas.
1. Weak thermocouple.
2. Input too high.
3. Cover around pilot lighter
hole not air tight.
4. Vent tubes not properly
installed or sealed.
Pilot and
Main Burner
go out During
Normal
Operation
1. Check millivoltage and replace if low.
2. Check input rate.
3. Tighten wing nuts securing cover and sight glass. Check and replace gasket if needed.
4. Follow instructions. Check both exhaust and air intake tubes, and vent cap. Be sure all
gaskets are in place and properly sealed. Use only tubes and vent cap supplied. Do not
alter vent tubes or cap.
1. Gas input not checked.
2. Clogged orifice.
1. Thermostat set too high.
2. Combination control valve stuck
open.
Incorrect
Gas Input
Too Much
Heat
1. Re-check gas input.
2. Clean orifice with a smooth wood toothpick, do not enlarge.
1. Lower temperature setting.
2. Replace combination control valve.
Please follow the following corrective actions in order.
1. Furnace undersized.
2. Thermostat set too low.
3. Incorrect supply pressure.
Not Enough
Heat
1. This is especially true when a dwelling or room is enlarged. Have the heat loss
calculated and compare to furnace output. Your gas company can supply you with
this information. If furnace is undersized, replace with correct size unit.
2. Raise temperature setting.
3. Check supply pressure.
