7
33 LIMIT CIRCUIT FAULT
– Indicates the limit, or flame rollout is open or the furnace is operating in high--heat only mode due to 2 success-
ive low heat limit trips. Blower will run for 4 minutes or until open switch remakes whichever is longer. If open longer than 3 minutes, code
changes to lockout #13. If open less than 3 minutes status code #33 continues to flash until blower shuts off. Flame rollout switch requires
manual reset. Check for:
Proper rear air baffle.
Loose blower wheel.
Defective switch or connections.
Improper low--heat gas input adjustment.
Stuck high--heat solenoid in gas valve
Improper or misaligned limit and/or limit shield.
34 IGNITION PROVING FAILURE
– Control will try three more times before lockout #14 occurs. If flame signal is lost during blower
on--delay period, blower will come on for the selected blower off--delay. Check for:
Low inlet gas pressure.
Control ground continuity.
Gas valve defective or turned off.
Defective Hot Surface Igniter.
Manual valve shut off.
Oxide buildup on flame sensor (clean with fine steel wool).
Proper flame sense micro amps (.5 micro amps DC min., 4.0 – 6.0 nominal).
Green/Yellow wire MUST be connected to furnace sheet metal.
Inadequate flame carryover or rough ignition.
Flame sensor must not be grounded.
41 BLOWER MOTOR FAULT
– Indicates the blower failed to reach 250 RPM or the blower failed to communicate within the prescribed time
limits. Thirty seconds after being turned ON or ten seconds during steady--state operation.
42 INDUCER MOTOR FAULT
– Indicates the inducer has not started within 20 seconds after a call for heat, the inducer motor RPM is outside
its valid range of operation, or the inducer RPM signal was lost for 5 seconds during operation. Check for:
Proper vent sizing.
Restricted combustion air supply.
Failed inducer motor.
Improper motor wiring.
43 LOW--HEAT PRESSURE SWITCH OPEN WHILE HIGH--HEAT PRESSURE SWITCH IS CLOSED
– Check for:
Low inlet gas pressure (if LGPS used).
Plugged condensate drain.
Improper pressure switch wiring.
Water in vent piping, possible sagging pipe.
Stuck open low--heat pressure switch.
Disconnected or obstructed pressure tubing.
45 CONTROL CIRCUITRY LOCKOUT
– Auto--reset after 1 hour lockout due to:
Flame sense circuit failure.
Gas valve relay stuck open.
Software check error.
Reset power to clear lockout. Replace control if status code repeats.
COMPONENT TEST
To initiate the component test sequence, shut “OFF” the room thermostat or disconnect the “R” thermostat lead. Reset power and then put
setup switch “SW1--6” in the ON position to start the component test sequence. Once initiated the furnace control will turn the inducer ON at
high--heat speed. The inducer motor will run for the entire test. The hot surface igniter and blower motor will be turned ON for 15 seconds
each. When the blower is turned OFF the inducer will be turned OFF. When the component test is completed one or more of the following
codes will flash.
LED CODE
DESCRIPTION
11
Indicates the blower motor tested OK. Visual check of inducer motor and hot surface igniter required.
25
SETUP ERROR
– Same as code 25 above.
41
BLOWER MOTOR FAULT
– Indicates blower motor failed test. Check blower, wiring, and furnace control.
42
INDUCER MOTOR FAULT
– Indicates inducer motor failed test. Check inducer, wiring, and furnace control.
To repeat component test turn setup switch “SW1--6” OFF and then back ON. After component test is completed put setup switch “SW1--6”
in the OFF position and reconnect the “R” thermostat lead.
