Wayne SC80, Руководство пользователя

Страница: 20 / 29

20
MORE SERVICE HINTS
THERMOSTAT CALLS FOR HEAT AND THE FOLLOWING CONDITIONS OCCUR:
1. PROBLEM: The combustion fan motor is not operating.
Possible Reasons:
a. Power is not on.
b. Circuit breaker tripped.
c. Thermostat in the off position.
d. Thermostat connections to T-T terminals on junction box have shorted to the junction box.
e. Bad thermostat.
f. Blower wheel jammed
g. Debris stuck in blower wheel blades.
h. 24 volt transformer is not functioning properly.
i. Thermostat leads not connected to the T-T terminals.
j. Motor shorted out due to overvoltage.
k. Motor start relay not functioning properly.
2. PROBLEM: Combustion fan motor runs but ignition sequence does not occur.
Possible Reasons:
a. Blower motor endswitch not closed which completes the 24 volt circuit to the gas primary.
b. The blower motor is not reaching full rpm due to debris on wheel.
c. Low voltage to the blower motor.
d. Loose connections on the 24 volt circuit after the endswitch or between fan relay and the 24 volt side of the
gas primary.
e. The gas ignition control is defective and must be replaced.
3. PROBLEM: Combustion fan motor runs and ignition sequence initiated but goes into lockout.
Possible Reasons:
a. Spark electrode rod is cracked shorting spark to ground.
b. Loose connection on spark electrode rod.
c. Gas primary control not allowing 24 volts to gas valve.
d. Gas valve shorted out or defective.
e. No ground between burner and appliance.
f. Spark electrode location shifted.
g. Ignition control not generating spark.
h. Ignition wire insulation melted and is grounding out on burner.
i. Gas supply is not turned on.
j. Gas manifold pressure is too high.
k. Gas manifold pressure is too low.
l. High negative draft conditions.
m. Gas supply line is undersized.
n. Multiple appliances operating on undersized line.
o. Insufficient combustion air flow.
p. Incorrect air shutter adjustment allowing too much combustion air to enter burner.