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Status Code 7
LIMIT CIRCUIT LOCKOUT – Lockout occurs if the limit or flame rollout switch is open longer than 3 minutes or 10
successive limit trips occurred during maximum-heat. The modulating furnace control will auto-reset in 3 hours. Flame roll-
out switch(es) FRS require manual-reset.
STEP
ACTION
YES
NO
GO TO
1.
Remove the blower door. Disconnect communication connector PL7 (if used) or the R
thermostat lead (if used) from the furnace control board.
2
2.
Depress the door switch. Use piece of tape to hold it closed.
3
3.
Does status code 4 flash?
11
4
4.
Does a different status code flash?
5
6
5.
Go to page number indicated in the Index for the section covering the status code.
INDEX
6.
Jumper R and W/W1 thermostat terminals.
7
7.
Observe the furnace operation for 25 minutes or until status code starts flashing.
8
8.
Does status code 4 flash?
26
9
9.
Does a different status code flash?
5
10
10.
Go to page number indicated in Index for CLEANUP AND START-UP INSTRUCTIONS.
INDEX
11.
Is 24-vac across connector terminal PL1-6 and C
OM
-24V on modulating furnace control?
13
12
12.
Replace the modulating furnace control.
10
13.
Is 24-vac across connector terminal PL1-8 and C
OM
-24V on modulating furnace control?
12
14
14.
Turn power off.
15
15.
Do you have continuity across limit switch LS?
17
16
16.
Replace limit switch LS.
10
17.
Do you have continuity across each flame rollout switch FRS?
25
18
18.
Can flame rollout switch FRS be reset?
20
19
19.
Replace flame rollout switch FRS.
10
20.
Reset flame rollout switch FRS, install both doors, turn power on, and observe furnace
operation for two 15 minute cycles.
21
21.
Does the flame rollout switch FRS trip again?
23
22
22.
Does a different status code flash?
5
10
23.
You have inadequate combustion-air supply. This may be caused by:
- Reversed vent and combustion-air pipes.
- Poor burner, manifold, or orifice alignment.
- Blocked heat exchanger.
- Leak in secondary heat exchanger.
- Leak somewhere between primary and secondary heat exchangers.
- Leak between vestibule and blower compartment.
- Flue gas leak in vestibule.
24
24.
Fix problem
10
25.
You have an open RED wire or bad terminal in limit circuit. Repair wire or replace harness.
10
26.
Does furnace have the proper limit switch? If so, is the limit gasket also installed?
27
24
27.
Remove tape from door switch, turn power off at main disconnect, and remove jumper across
R and W/W1.
28
28.
Is blower wheel firmly mounted on motor shaft?
29
24
29.
Does the model plug PL4 match the part number specified on the Rating Plate?
31
30
30.
Replace model plug.
10
31.
Lockout may have been caused by excessive return-air restriction. Check all dampers, filters,
and return-air grilles for blockage. Add more return-air openings if necessary. Use
Appendix D to evaluate external static pressure. Reference status code 4 for additional
troubleshooting steps.
10
440 08 4001 00
Содержание 9MAC/E series
Страница 39: ...39 Fig 2 Wiring Schematic 440 08 4001 00...
Страница 41: ...41 Figure 3 ECM Blower Motor 440 08 4001 00...
Страница 48: ...48 Replaces New Form ICP Eng 3 12 440 08 4001 00...