I have a Bryant 373LAV/376CAV Gas Furnace. I started having a problem with it and can't find the FLASHING LED ERROR CODES anywhere. After reading some of the answer in these forums I'm assuming the LED flashes x times short, then x times long for a 2 digit number. I'm getting a 3 short 3 long flash which I assume is code 33.

Here is the scenario.

The system goes through the normal startup cycle like this (just so you-all know that I know what is normal):

Power on the unit
LED comes on solid red
Turn on and up thermostat (call for heat)
Small fan turns on
10+ seconds go by
Glow starter lights up
15+ seconds go by
Gas valve opens
Burners come on
45-60 seconds of warm up time
Blower motor starts

After a while, the gas shuts off and the error code 33 starts flashing (thermo is still calling for heat).

If I turn off power to the unit (to reset it) then power it back up, the blower motor come on right away and the error code changes to 12. After a short while the LED goes solid red again and the heat cycle starts again like normal and it fires up again.

SO... what is code 33? Loss of gas? Overheating due to maybe clogged filters? All I can do is guess until I have these codes. WHERE CAN I GET THE CODE? WHERE CAN I GET A SERVICE MANUAL? Stupid Bryant web site does not provide any helpful info at all!! Too bad for the do it yourself person!

THANKS FOR ANY HELP!!

Codes are on the front of the blower door. Sounds like the flame sensor is dirty and it is sensing a weak flame, just my best guess from here.

codes are on the front of the blower door. Sounds like the flame sensor is dirty and it is sensing a weak flame, just my best guess from here.

33 - Limit or flame roll-out switch is open

Doah! I looked and there they were, plane as day, the codes, right on that stupid sticker on the cover!! Sorry, I guess I was so focused on one thing I missed the obvious. I even DID read the sticker on the cover for the propane conversion, but didn't see the code sticker!!

Anyway, I didn't include all the "possible reasons" for this, too much to type, but one of them did say something about restricted air flow. So that's what I'm testing now. Cleaned the filters and opened all the registers to max, just to see if the problem goes away...

That seams to have done the trick. Not a day too soon either. The temp this morning was 27! So I guess I had restricted airflow. I will keep watch on it for a few more days and report back if anything changes.

Thanks!