Status Code 11 - No Previous Code; Status Code 12 - Blower On After Power Up - Bryant 355CAV A Series Troubleshooting Manual

Status Code 11
NO PREVIOUS CODE - Stored status codes are erased after 72 hours or can be cleared by jumpering R, W/W1, and Y/Y2
thermostat leads while setup switch SW1-1 is ON. Run system through a heating or cooling cycle to check system.
This usually indicates one of the following:
- The status history has been cleared and setup switch SW1-1 is in the ON position.
- Component test was successfully completed and setup switch SW1-6 is in the ON position.
STEP
1. Remove the blower access panel, depress the door switch. Use piece of tape to hold it closed.
2. Is setup switch SW1-1 in the ON position.
3. Put setup switch SW1-1 in the OFF position.
4. Go to the page number indicated in Index for the CLEANUP AND STARTUP
INSTRUCTIONS.
5. Is setup switch SW1-6 in the ON position.
6. Put setup switch SW1-6 in the OFF position.
7. Jiggle setup switches SW1-1 and SW1-6 back and forth. If status code 11 continues to flash
replace the variable speed furnace control
Status Code 12
BLOWER ON AFTER POWER UP - Blower will run for 90 seconds when furnace power is interrupted and later restored during
a call for heat (R-W/W1 closed) or if the call for heat is interrupted (R-W/W1 opens) during the blower on-delay period. If this
status code repeats every couple of minutes it is probably caused by a direct short in the pressure switch circuits, gas valve
GV, throttling valve TV, wiring to gas valve GV, wiring to throttling valve TV, or humidifier coil.
STEP
1. Remove the blower access panel and disconnect User Interface ABCD connector (if used) or
the R thermostat lead (if used) from the furnace control board.
2. Depress the door switch. Use piece of tape to hold it closed.
3. Jumper R and W/W1 thermostat terminals.
4. Does the furnace keep repeating the following cycle?
Induced draft motor IDM runs, induced draft motor IDM stops, blower motor BLWM runs for
90 seconds while AMBER LED status light flashes status code 12.
5. Do you have less than 17-vac across R and C
6. Do you have less than 90-vac across L1 and L2 on the variable speed furnace control?
7. Make sure wire gage between main fuse box and furnace complies with wire size specification
in Installation, Start-Up, and Operating Instructions.
8. Fix problem.
9. Go to the page number indicated in Index for the CLEANUP AND STARTUP
INSTRUCTIONS.
10. Disconnect the R thermostat lead.
11. Do you have less than 19-vac across R and C
12. Replace transformer.
13. The thermostat and/or thermostat wires are loading down the transformer. Replace the
thermostat or repair thermostat wires.
14. Does the hot surface igniter HSI come on during the cycle?
15. Disconnect the humidifier lead from HUM terminal on variable speed furnace control.
16. Does the furnace still alternately cycle induced draft motor IDM and blower motor BLWM as
described in Step 4.
17. The humidifier may not be wired into the system properly or there is a direct short in wiring to
humidifier solenoid coil, diode bridge(if used), or humidifier solenoid coil.
18. There is a short in the gas valve GV or wiring to gas valve GV. Refer to Appendix E to check
gas valve GV.
19. There is a direct short in the ORANGE wire from the low heat pressure switch LPS.
20. While the unit is operating in low heat jumper R and W2 thermostat terminals.
ACTION
ACTION
-24V on the variable speed furnace control?
OM
-24V on the variable speed furnace control?
OM
- 15 -
YES NO GO TO
2
3 5
4
INDEX
6 7
4
4
YES NO GO TO
2
3
4
5 20
6 14
7 10
8
9
INDEX
11
12 13
9
9
15 27
16
18 17
8
8
8
21