Fig. 15—Service Label A93305
To initiate the component test sequence, shut "OFF" the room thermostat or disconnect the "R" thermostat
lead. Put setup switch "SW-6" in the "ON" position to start the component test sequence. Once initiated the
main board will turn "ON" the inducer motor-low speed, inducer motor-high speed, hot surface ignitor, blower
motor-low speed, and blower motor-high speed for 15-20 seconds each. When component test is completed
one or more of the following codes will flash.
CODE DESCRIPTION
11 Indicates inducer and blower motor tested OK. Visual check of hot surface ignitor required.
22 SETUP ERROR - Same as code 22 above.
41 BLOWER OUTSIDE VALID SPEED RANGE - Indicates blower motor failed test. Check blower, wiring,
and control center.
42 INDUCER OUTSIDE VALID SPEED RANGE - Indicates inducer motor failed test. Check inducer,
wiring and control center.
To repeat component test turn setup switch "SW-6" "OFF" and then back "ON". After component test is
completed put setup switch "SW-6" in the "OFF" position and reconnect the "R" thermostat lead.
COMPONENT TEST

STATUS CODE EXAMPLE

34 IGNITION PROVING FAULT - Control will try three more times before a locko ut #14 occurs.
Check for: - Gas valve turned "OFF".
- Oxide buildup on flame sensor (clean with fine sandpaper.)
- Main shutoff valve turned "OFF".
- Green wire MUST be connected to furnace sheet metal.
- Proper flame sense microamps (.5 microamps D.C. minimum)
- Inadequate flame carryover or rough ignition.
- Low inlet gas pressure
41 BLOWER OUTSIDE VALID SPEED RANGE - Indicates the blower is not operating at the calculated RPM.
If this fault occurs in conjunction with fault #44 check wiring to motor otherwise refer to the
trouble-shooting guide.
42 INDUCER OUTSIDE VALID SPEED RANGE - Indicates the inducer is not operating at the calculated RPM,
or has not started within 10 seconds after a call for heat. Check wiring to motor otherwise refer to
the trouble-shooting guide.
43 PRESSURE SWITCH CALIBRATION FAULT - Indicates the low and high pressure switch "make" points
during high heat purge are not within the calibration range.
Check for: - Plugged condensate drain.
- Water in vent piping, possibly sagging pipe.
- Improper pressure switch wiring or pressure switch tubing connections.
- Failed or "Out of Calibration" pressure switches.
44 BLOWER CALIBRATION FAULT - Indicates the calculated blower speed is below 250 or above 1300
RPM. Unit will default to low or high heat mode if possible. If this fault occurs in conjunction with
fault #41 check wiring to motor otherwise refer to the trouble-shooting guide. If this fault occurs by
itself check for undersized ductwork, or excessive static caused by a dirty filter, or closed registers.
320624-101 REV. E
SPEED RANGE
INDUCER OUTSIDE VALID
=42 FAULT
HUMGRY/Y2W/W1CW2
MALFUNCTION
MICROPROCESSOR
RED LED2
EMER HT.
RED LED1
(2)
FLASHES
NO. OF
COUNT THE
(4)
FLASHES
NO. OF
COUNT THE
LOW HT.
LED4
GREEN
HIGH HT.
LED3
YELLOW
4
3
2
1
FUSE
3
21
OFF
32
1
OFF
12345678
OFF
SETUP SW,(SW1-8)
—13—