Status Code 11 - - No Previous Code; Status Code 12 - - Blower On After Power Up - Carrier PG9UAA Troubleshooting Manual

STEP
12. Ensure the gas inlet pressure and burner orifice are correct. Then adjust the gas valve to the
proper rate. If it cannot be adjusted to the proper rate, replace the gas valve.
13. Is outdoor condensing unit operating during heating cycle?
14. Check temperature rise and external static pressure with blower access panel in place. Tem-
perature rise should be mid range or higher than midpoint of range stated on furnace rating
plate. External static pressure must not exceed .7 in.w.c. If return temperature is below 60
deg. F condensation may form on heat exchangers. If left uncorrected failure will result.
15. Check return air ducts in unheated spaces for leaks.
16. Fix problem.
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 sys-
tem.
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 INSTRUC-
TIONS.
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, wiring to gas valve GV, or humidifier coil.
STEP
1. Remove the blower access panel and disconnect the R thermostat lead 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
furnace control?
6. Do you have less than 90- -vac across L1 and NEUTRAL- -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.
ACTION
ACTION
ACTION
V on the variable speed
OM- - 24
12
YES NO
16 14
YES NO
3 5
6 7
YES NO GO TO
2
3
4
5 20
6 14
7 10
8
9
INDEX
GO TO
9
15
9
9
GO TO
2
4
INDEX
4
4