ICP 9MAC/E series Troubleshooting manual - page 35
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STEP
ACTION
YES
NO
GO TO
23.
Reconnect PL16 to the inducer motor and put setup switch SW1-6 in the OFF position.
24
24.
Does inducer wheel turn freely?
26
25
25.
Replace the inducer motor control (if you have a 2 piece design) or the inducer motor
assembly.
8
26.
Does the inducer wheel rub against inducer housing?
15
25
27.
Does status code 4 + 2 flash within 20 seconds after a call for heat?
28
39
28.
Turn power off and disconnect jumper from the R and W/W1 thermostat terminals.
29
29.
Disconnect collector box tube to pressure switch assembly.
30
30.
Turn power on and jumper the R and W/W1 thermostat terminals.
31
31.
Does status code 4 + 2 flash within 20 seconds after a call for heat?
32
33
32.
Reconnect collector box tube to pressure switch assembly.
34
33.
Reconnect collector box tube to pressure switch assembly.
40
34.
Disconnect jumper across R and W/W1 thermostat terminals.
35
35.
Check the RPM feedback line. To do this connect a DC voltmeter across terminals PL16-1
BROWN (+) and PL16-3 ORANGE (-), then put setup switch SW1-6 for COMPONENT
TEST in the ON position. Does the voltage across PL16-1 and PL16-3 change between
states as shown below?
- State 1 – OFF (15.0 – 17.0 vdc)
- State 2 – MED (12.0 – 14.0 vdc)
36
25
36.
Turn power off.
37
37.
Do you have continuity between PL16-3 and PL1-7?
11
38
38.
You have an open wire or bad terminal on the ORANGE wire between PL16 and PL1.
15
39.
Does fault occur a few seconds after the medium pressure switch MPS makes?
Note:
Check for 24-vac between the N.O. (Normally Open) contact on medium pressure
switch MPS and Com on the modulating furnace control to know when the medium pressure
switch MPS makes.
Note:
You may need to wait a few minutes for the modulating furnace control to ramp the
inducer motor back up to speed.
40
55
40.
Is the inducer motor rotating in direction shown on inducer housing?
41
25
41.
Turn power off and disconnect jumper from the R and W/W1 thermostat terminals.
49
42.
Connect 1 side of slope manometer with a tee to collector box pressure tap. Refer to pressure
check diagram in Appendix C.
43
43.
Turn power on and jumper the R and W/W1 thermostat terminals.
44
44.
Do you have more than 1.08 in. wc pressure drop across heat exchangers when medium
pressure switch MPS makes?
Note:
Check for 24-vac between the N.O. (Normally Open) contact on medium pressure
switch MPS and Com on the modulating furnace control to know when the medium pressure
switch MPS makes.
45
46
45.
Replace the pressure switch assembly.
8
46.
Turn power off.
47
47.
Is inducer wheel okay?
54
48
48.
Replace the inducer motor assembly.
8
49.
Check the collector box pressure tap for blockages. Use the back end of a small drill bit to
clear debris out of the collector box pressure tap opening. It may be necessary to remove the
collector box and clear away the debris if it keeps clogging.
50
50.
Check the tubing between the collector box and the pressure switch assembly for leaks or
blockages.
51
51.
Check the tube between the pressure switches for leaks or blockages.
52
52.
Check the unused trap openings and make sure they are plugged.
53
53.
Were there any leaks or blockages found in steps 49-52?
15
42
54.
You have excessive restriction in the vent pipe. Also check for proper vent sizing for
installation.
15
55.
Make sure all pins and wire leads are intact on connectors between modulating furnace
control and the inducer motor.
56
56.
Replace the inducer motor control (if you have a 2 piece design) or the inducer motor
assembly. If problem still persists after replacing the inducer motor, contact your distributor.
8
57.
Turn power off and disconnect jumper from the R and W/W1 thermostat terminals.
58
58.
Install the control door.
59
59.
Turn power on and jumper the R and W/W1 thermostat terminals.
60
60.
Does status code 4 + 2 flash?
62
61
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