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All lockout conditions can be cleared immediately provided
that the original fault causing the lockout is cleared and
power to the unit is cycled off and then back on again or
(soft lockout only) if a heat call is cycled off for greater
than 2 seconds but less than 20 seconds.
The furnace control will not initiate a heat cycle during any
lockout condition. A call for compressor or continuous fan
will generally be responded to but control will display the
lockout error fault code instead of the "C" (for compressor)
or "F" (for Continuous fan).
FIVE-MINUTE LOCKOUT
A five minute "soft" lockout will be initiated if the low pres-
sure switch fails to close after 60 seconds of continuous
inducer operation at the beginning of a normal heat cycle
(pressure switch proving period). The seven-segment dis-
play will display the appropriate fault. Lockout will auto-
matically be reset after five minutes.
ONE-HOUR LOCKOUT
A one hour "soft" lock out will be initiated when:
-
Flame has not been detected after four igni-
tion trials.
-
Flame has been lost for five times in one heat
call.
-
Undesired flame has been detected. The one-
hour period will commence after flame is no
longer detected.
-
Dead Blower has been detected (main limit
circuit open for more than 150 seconds)
-
When voltage has unexpectedly been de-
tected on the gas valve circuit and voltage
goes away when inducer is shut off.
If a Water Sensed condition is detected once
-
during heat call (heat cycle terminated in re-
sponse to fault) and then clears and then is
detected again within 5 minutes of the next
heat attempt (same heat call).
The seven-segment display will alternately display " 10 "
and the code number for the fault causing the lockout.
Lockout will automatically be reset after one hour.
HARD LOCKOUT
Three conditions shall cause a hard lockout:
1. The control senses an unspecified internal fault. Fault
code " 93 " is set and displayed. This lockout condition can-
not be reset by cycling the heat call.
2. Voltage is detected unexpectedly on the gas valve con-
tacts (welded relay) and will not clear by cycling
74
the inducer . Fault code " 93 " is set and displayed. This
lockout condition cannot be reset by cycling the heat call.
3. The furnace control will declare that the blower motor is
inoperable (dead) if the main limit control has been open
for more than 150 seconds. Gas heating is terminated.
However, the control continues to try to operate heating
for up to four attempts in case the blower motor starts
working again. If a dead blower has been declared four
times in one heat call, the furnace control enters a hard-
lockout. Fault code " 61 " is set and displayed. This lockout
condition CAN be reset by cycling the heat call.
REPLACING THE FURNACE CONTROL
In the event that the furnace control must be replaced, the
model data card must be removed from the original fur-
nace control and retained with the furnace. A plastic tether
with a note wrapped around the tether is used to remind
the technician not to remove the card from the furnace.
Use this card to insert into the model data card connector
labeled P6 of the replacement control board. Failure to
save and connect the model data card properly to the re-
placement control may result in no operation or undesired
operation of the furnace.
When replacing the furnace control, be sure to match the
dipswitch settings of the original control on the replace-
ment.
DO NOT CUT THE PLASTIC WIRE TIE USED AS A
TETHER TO THE ATTACHED MODEL DATA CARD.
DOING SO WILL DEFEAT THE PURPOSE OF RETAIN-
ING THE MODEL DATA CARD – WHICH COULD LEAD
TO A LOSS OF CRITICAL DATA NECESSARY TO OP-
ERATE THE FURNACE. THE CARD MUST STAY WITH
THE FURNACE – EVEN WHEN THE FURNACE CON-
TROL (IFC) MUST BE REPLACED. NEVER USE A
CONTROL BOARD TAKEN FROM ANOTHER FURNACE
AS A REPLACEMENT CONTROL FOR THIS FURNACE.
FURNACE CONTROLS TAKEN FROM OTHER FUR-
NACES MAY CONTAMINATE THE SYSTEM WITH THE
WRONG MODEL DATA WHICH CAN ONLY BE FIXED
BY REPLACING THE MODEL DATA CARD WITH THE
ORIGINAL MODEL DATA CARD FROM THE ORIGINAL
FURNACE OR A REPLACEMENT MODEL DATA CARD
DESIGNED FOR THE ORIGINAL FURNACE.
DIAGNOSING BLOWER MOTOR
ISSUES
If the main circulating blower motor will not operate when
it should, there are some different methods for diagnosing
the problem.
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