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TROUBLESHOOTING
Continued
OBSERVED PROBLEM
POSSIBLE CAUSE
No heat (continued)
7. Blower not operating
8. Short cycling (motor goes on and off)
The electronic system is made up of two
IGNITION FAILURES
parts: the ignition control and the glo-bar.
The ignition control is the brain of the
electronic
WARNINGS:
functions:
• Never connect unit or ignition
1. When the blower reaches full r.p.m., a
circuit to 230 volts.
24-volt circuit is completed to the
• Never operate unit with glo-bar
ignition control. (Check across yellow
touching burner or any other
and green wires.)
ground.
Damage
to
ignition
2. The white and blue wires at the ignition
control will occur.
control are the 120-volt input for the
• Be sure sensor probe never
glo-bar circuit. When the 24-volt circuit
touches glo-bar. This will damage
is completed, the ignition control will
ignition control.
complete the 120-volt circuit to the glo-
bar and it begins to glow. (Check this
• If the ignition control is defective,
circuit across the two white wires at
it must be replaced. It is not field-
the ignition control.)
repairable.
3. After approximately 20 seconds, a 24-
volt circuit is completed through the
CAUTION: Do not attempt to
ignition control to the gas valve. (This
repair the ignition control. This may
circuit is checked from brown wire at
alter it and cause it to operate
ignition control to a neutral ground.)
incorrectly.
REM EDY
7. A. Check power supply to furnace.
B. Check electrical connections at furnace.
C. With thermostat points closed, check for circuit
completion at motor. If voltage is present,
replace motor. If no voltage is present at
motor, 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 contact 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
approximately 4.0 amps.
• If amp draw is within limits, check for shorts in
thermostat wiring.
• If wiring is okay, replace thermostat.
This circuit opens the valve, gas flows
to the burner and is ignited by the heat
from the glo-bar. Note: Glo-bar
system.
It
has
several
remains on.
4. When the burner flame is established,
the sensing probe will sense the
presence of burner flame and open the
glo-bar circuit. The glo-bar will then
stop glowing.
It is important to determine the type of
problem being experienced. Then the
proper checkout procedure can be made.
The following is a list of problems, how to
identify in which area the problem is
located, and how to correct it.
15
TROUBLESHOOTING
Continued
OBSERVED PROBLEM
POSSIBLE CAUSE
Ignition failures
1. Glo-bar will not glow - with blower run-
ning and microswitch engaged
2. Glo-bar glows but burner will not come
on
3. Glo-bar operating and gas valve open-
ing but burner will not light
4. If the ignitor remains on after main
burner ignition or the valve chatters,
reverse the 120 volt A.C. connections
at the wall receptacle
REM EDY
1. Check the following:
A. Check for 24 volts A.C. across yellow and
green wires at ignition control. If no voltage,
check microswitch and limit switch for circuit
completion as well as wiring and wiring
connections.
B. Voltage present across yellow and green
wires, check for 120-volt input to ignition
control across white and blue wires. If no
voltage, check wiring all the way back to
power supply.
C. 120 volts present across white and blue wires,
check for 120 volts across the two white wires
at ignition control. If no voltage, replace
ignition control.
D. Voltage present across the two white wires,
check wiring and wire connections to glo-bar.
E. If wiring and wire connections okay, replace
glo-bar. (Glo-bar broken)
2. A. Check for voltage (24 volts A.C.) at valve 40
seconds after glo-bar begins to glow. If
voltage present but valve not opening, replace
valve.
B. If no voltage at valve, check brown wire at
ignition control for continuity and good
connection.
C. If wire and wire connections okay, replace
ignition control.
3. A. Check gas flow through burner. If no gas is
coming through burner, check for obstruction
in gas line, main burner orifice, or main burner.
B. If thermostat okay, check for 24 volt A.C.
circuit completion across yellow and green
wires at ignition control. If no voltage, check
for circuit completion through limit switch and
microswitch.
C. If voltage is present at ignition control across
yellow and green wires yet burner continues
to go off, replace ignition control.
4. A. If polarity is okay yet burner continues to go
off, check thermostat to be sure it is still
completing the valve circuit. If not, check for
excessive amp draw in valve circuit.
B. If thermostat okay, check for 24 volt A.C.
circuit completion across yellow and green
wires at ignition control. If no voltage, check
for circuit completion through limit switch and
microswitch.
C. Voltage present at ignition control across
yellow and green wires yet burner continues
to go off, replace ignition control
16
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