Ignition Failures - Williams 2503532 Owner's Operation And Installation Manual

THE COMFORT PRODUCTS PEOPLE
DIRECT-VENT NATURAL GAS HEATER
TROUBLESHOOTING
Continued
OBSERVED PROBLEM
No heat (continued)

IGNITION FAILURES

WARNINGS:
• Never connect unit or ignition
circuit to 230 volts.
• Never operate unit with glo bar
touching burner or any other
ground. Damage to ignition
control will occur.
• Be sure sensor probe never
touches glo bar. This will dam-
age ignition control.
• If the ignition control is defec-
tive, it must be replaced. It is
not field-repairable.
CAUTION: Do not attempt to
repair the ignition control. This
may alter it and cause it to oper-
ate incorrectly.
POSSIBLE CAUSE
7. Blower not operating
8. Short cycling (motor goes on and off)
The electronic system is made up of two
parts: the ignition control and the glo bar.
The ignition control is the brain of the elec-
tronic system. It has several functions:
1. When the blower reaches full r.p.m., a
24-volt circuit is completed to the ig-
nition control. (Check across yellow
and orange wires.)
2. The red and blue wires at the ignition
control are the 120-volt input for the
glo-bar circuit. When the 24-volt cir-
cuit is completed, the ignition control
will complete the 120-volt circuit to the
glo bar and it begins to glow. (Check
this circuit across the two white wires
at the ignition control.)
3. After approximately 20 seconds, a 24-
volt circuit is completed through the ig-
nition control to the gas valve. (This cir-
cuit is checked from brown wire at ig-
REMEDY
7. A. Check power supply to furnace
B. Check electrical connections at furnace
C. With thermostat points closed, check for cir-
cuit completion at motor. If voltage is present,
replace motor. If no voltage is present at mo-
tor, check for:
• 24 volts on secondary coil or transformer. If
no voltage, replace transformer.
• If 24 volt transformer okay, check for circuit
completion across contacts on time delay
relay. Allow three to five seconds for con-
tact to close
• If circuit across contacts okay, check conti-
nuity of wiring in motor circuit
8. A. Check thermostat. Contacts should remain
closed. If contacts are breaking:
• Check thermostat anticipator setting. It
should be between .75 and 1.0
• If anticipator setting okay, check amp draw
across thermostat. If amp draw exceeds .65,
check amp draw across coil of valve and time
delay relay. Note: On initial operation of glo
bar, there is a momentary surge of approxi-
mately 4.0 amps
• If amp draw is within limits, check for shorts
in thermostat wiring
• If wiring is okay, replace thermostat
4.
It is important to determine the type of
problem being experienced. Then the proper
checkout procedure can be made. The fol-
lowing is a list of problems, how to identify
in which area the problem is located, and
how to correct it.
16
nition control to a neutral ground.) This
circuit opens the valve, gas flows to the
burner and is ignited by the heat from
the glo bar. Note: Glo bar remains on.
When the burner flame is established,
the sensing probe will sense the pres-
ence of burner flame and open the glo-
bar circuit. The glo bar will then stop
glowing.
201842