- 31 -
STEP
ACTION
YES
NO
GO TO
25.
Do you have continuity between PL8-2 and PL17-2?
Note:
The terminals in PL8 can be permanently damaged if the voltmeter probe is jammed
into the terminal end of the connector. Use caution when checking.
13
26
26.
You have an open wire or a bad terminal on the YELLOW wire between connector PL8 and
PL17. Repair or replace the wire harness.
8
27.
Put setup switch SW1-6 in the OFF position.
28
28.
Connect a DC voltmeter across terminals PL17-3 ORANGE (+) and PL17-4
GREEN/YELLOW (-). Is there 5-vdc across the ORANGE and GREEN/YELLOW wires?
29
17
29.
Check the gas valve PWM output. To do this connect a DC voltmeter across terminals PL17-
3 ORANGE (+) and PL17-4 GREEN/YELLOW (-) then run COMPONENT TEST by
turning setup switch SW1-6 ON. In approximately 17 seconds the voltage will drop briefly
from 5.0-vdc. The voltage drop will be several volts or more and will last for 1 to 2 seconds.
If everything is working properly this will happen once. If power was reset before running
the COMPONENT TEST there will be 2 shorter duration voltage drops spaced further apart.
The time between these voltage drops depends on whether the valve has been converted to
propane.
30
30.
Does the voltage drop as described in step 29?
31
17
31.
Put setup switch SW1-6 in the OFF position.
32
32.
Connect a DC voltmeter across terminals PL8-3 ORANGE (+) and C
OM
-24V (-)then run
COMPONENT TEST by turning setup switch SW1-6 ON.
33
33.
Does the voltage drop as described in step 29?
13
34
34.
You have an open wire or a bad terminal on the ORANGE wire between connector PL8 and
PL17. Repair or replace wire harness.
8
35.
Does status code 3 + 5 flash when the blower turns on?
37
36
36.
24-vac power to the stepper motor electronics is intermittent. Disconnect connector PL8 and
PL17 and check the terminals at both ends of the RED wire. Repair or replace the wire
harness.
8
37.
Disconnect jumper wire across R and W/W1 thermostat terminals and wait for the blower to
turn off.
38
38.
Disconnect all accessories (humidifiers and/or EAC’s).
39
39.
Jumper the R and W/W1 thermostat terminals.
40
40.
Does status code 3 + 5 flash when the blower turns on?
43
41
41.
One of the accessories disconnected is creating electrical interference with the gas valve.
Either isolate the accessory with a relay or replace the accessory.
42
42.
Fix the problem.
8
43.
Either the blower motor is creating electrical interference with the gas valve or the gas valve
is overly sensitive. Replace the gas valve. If the problem persists replace entire blower motor
including the blower control module.
42
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