COZY DVCF403C-H Installation And Operating Instructions Manual page 18

TROUBLESHOOTING CHART ( For Qualified Service Technician ) - MAIN BURNER
SYMPTOM POSSIBLE CAUSES
Flame Too 1. Defective operator section of valve.
Large
2. Burner orifice too large.
3. If installed above 2,000 feet.
Yellow Burner 1. Clogged burner ports.
Flame
2. Obstructions around vent cap.
1. Gas leak.
Gas Odor
Delayed 1. Pilot flame too small.
Ignition
2. Burner ports clogged at pilot.
3. Low gas pressure.
4. Pilot decreases in size when main
burners come on.
Failure 1. Main gas off.
to Ignite
2. Thermostat not set high enough to
call for heat.
3. Clogged burner orifice.
4. Thermostat wired wrong or
defective.
Burner Won't 1. Defective or damaged
thermostat wire, or thermostat.
Turn Off
2. Thermostat location.
3. Defective or sticking valve.
4. Excessive gas pressure.
Incorrect 1. Gas input not checked.
Gas Input
2. Clogged orifice.
Not Enough 1. Furnace undersized.
Heat
2. Thermostat set too low.
3. Incorrect supply pressure.
Too Much 1. Thermostat set too high.
Heat
2. Combination control valve stuck
open.
1. Weak thermocouple.
Pilot and
Main Burner
2. Input too high.
go out During
3. Cover around pilot lighter
Normal
hole not air tight.
Operation
4. Vent tubes not properly
installed or sealed.
Please follow the following corrective actions in order.
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. 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. 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. 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. Re-check gas input.
2. Clean orifice with a smooth wood toothpick, do not enlarge.
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.
1. Lower temperature setting.
2. Replace combination control valve.
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.
Page 17
CORRECTIVE ACTION
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1018028-A