035-19671-002 Rev. A (0704)
8
Unitary Products Group
5 RED FLASHES:
This fault is indicated if the normally closed contacts
in the rollout switch open. The rollout control is manually reset. If it has
opened, check for proper combustion air, proper inducer operation, and
primary heat exchanger failure or burner problem. Be sure to reset the
switch and cycle power (24 VAC) to the control after correcting the fail-
ure condition.
6 RED FLASHES:
This indicates that after the unit was operating, the
pressure switch opened 4 times during the call for heat. If the main
blower is in a "Delay on" mode it will complete it, and any subsequent
delay off period. The furnace will lock out for one hour and then restart.
7 RED FLASHES:
This fault code indicates that the flame could not be
established. This no-light condition occurred 3 times (2 retries) during
the call for heat before locking out. Low gas pressure, faulty gas valve,
dirty or faulty flame sensor, faulty hot surface ignitor or burner problem
may cause this. The furnace will lock out for one hour and then restart.
8 RED FLASHES:
This fault is indicated if the flame is lost 5 times (4
recycles) during the heating cycle. This could be caused by low gas
pressure, dirty or faulty flame sensor or faulty gas valve. The furnace
will lock out for one hour and then restart.
9 RED FLASHES:
Indicates reversed line voltage polarity or faulty wir-
ing. Both heating and cooling operations will be affected. Check polarity
at furnace and branch. Check furnace grounding including the trans-
former ground and L1 and neutral connections.
10 RED FLASHES:
Gas flow with no call for 1st stage heat. Check 1st
stage gas valve and gas valve wiring.
10 DOUBLE RED FLASHES:
2nd stage gas valve failure. Check 2nd
stage gas valve and gas valve wiring.
11 RED FLASHES:
This indicates that a primary or auxiliary limit switch
has opened its normally closed contacts and has remained open for
more than five minutes. This condition is usually caused by a failed
blower motor or blower wheel. Cycle power (24 VAC) to the control to
reset the hard lockout condition after correcting the failure condition.
STEADY ON RED:
Control failure. Replace control board. 60-MINUTE
AUTOMATIC RESET FROM LOCKOUT: This control includes a "watch-
dog" type circuit that will reset from a lockout condition after 60 minutes.
Operational faults 6,7,8 will be reset. This provides protection to an
unoccupied structure if a temporary condition exists causing a furnace
malfunction. An example would be a low incoming gas supply pressure
preventing unit operation. When the gas pressure is restored, at some
point the "watchdog" would restart the unit and pro-vide heat for the
house.
NOTE:
NOTE: If a flame is detected the control flashes the LED for 1/8
of a second and then enters a flame stabilization period.
DIAGNOSTIC FAULT CODE STORAGE AND
RETRIEVAL
The control in this furnace is equipped with memory that will store up to
five error codes to allow a service technician to diagnose problems
more easily. This memory will be retained even is power to the furnace
is lost.
Only a qualified service technician should use this feature.
The control stores up to five separate error codes. If more than five
error codes have occurred since the last reset, only the five most recent
will be retained. The furnace control board has a button, labeled
"LAST
ERROR"
that is used to retrieve error codes. This function will only
work if there are no active thermostat signals. So any call for heating,
cooling or continuous fan must be terminated before attempting to
retrieve error codes.
To retrieve the error codes, push the
LAST ERROR
button. The
LED
on
the control will then flash the error codes that are in memory, starting
with the most recent. There will be a two-second pause between each
flash code. After the error codes have all been displayed, the
LED
will
resume the normal slow green flash after a five second pause. To
repeat the series of error codes, push the button again.
If there are no error codes in memory, the
LED
will flash two green
flashes. To clear the memory, push the
LAST ERROR
button and hold it
for more than five seconds. The
LED
will flash three green flashes
when the memory has been cleared, then will resume the normal slow
green flash after a five-second pause.
Never bypass pressure switch to allow furnace opera-
tion. To do so will allow furnace to operate under poten-
tially hazardous conditions.
Do not try to repair controls. Replace defective controls
with UPG Source 1 Parts.
Never adjust pressure switch to allow furnace operation.
