I have an older Bryant furnace which won't stay on. Manual reset works, but it keeps shutting down in under 2 minutes.

Single red LED indicator is flashing code 33. It did flash 13 between my last two attempts at restarting, but went back to 33.

I've cleaned the air filter. Blower wheel was spinning.

Is there anything else a semi-competent Harry Homeowner should try before calling the pros?

-Rob

Not a HVAC by any stretch, but I have fixed a few issues on my Lennox furnace. Google led me to this.

Bryant Code 33

My Lennox had a similar code last year. I replaced the limit switches to no avail. After much troubleshooting I traced it back to a bad circuit board. I removed the board and found a black carbon deposit where a circuit had shorted out. I replaced the board and it still didn't work. Because I wasn't a certified tech they didn't want to give me a new board. I bought another and it fixed the issue. I brought back the first board I had purchased and they refunded my money for 1 board.

The issue with mine was the blower wasn't coming on, which made the high limit switch trip. The actual high limit switch code was a red herring.

This might help --> https://hvac-boss.com/furnace/...oubleshooting-guide/

ETA - Search term 'bryant furnace code 33' returns numerous links to HVAC Industry & DIY forums. Even those found on reddit seem to have valid/reliable troubleshooting info. Good Luck

Do you see flames or not? Easiest thing to check is if there is a flame but it goes out, remove flame sensor and scrub with green Scotch Brite pad.

If no flame you can check to see if hot surface ignitor is lighting up.

If gas valve isn't opening you can check your inducer fan and vacuum switch.

I'm not an HVAC person, just too cheap to pay someone fix my stuff.

quote:

Originally posted by Skins2881:
Do you see flames or not? Easiest thing to check is if there is a flame but it goes out, remove flame sensor and scrub with green Scotch Brite pad.

If no flame you can check to see if hot surface ignitor is lighting up.

If gas valve isn't opening you can check your inducer fan and vacuum switch.

I'm not an HVAC person, just too cheap to pay someone fix my stuff.

Sorry - yes. Flame. When I say that the manual reset process works (power off, wait, power on, flame & blower!), I meant that the flames flamed and then flamed out & blower shut down after about 2 minutes.

I'll give the flame sensor a scrub and see if that helps. Then, off to the interwebz...

Thanks.

-Rob

Have you turned all the power completely off and back on?

First things first...

Model and serial ?

quote:

Originally posted by Mustang-PaPa:
Have you turned all the power completely off and back on?

Yes. That’s the manual restart procedure.

-Rob

quote:

Originally posted by Excam_Man:
First things first...

Model and serial ?

Model # 383KAV048111
Serial # 0102A55294

-Rob

Bryant
Model # 383KAV048111
Serial # 0102A55294

Code 33, Limit or Flame Rollout is open.

Since it fires up, flame rollouts are not it.
Leaves you with an open high limit, as its the only other safety in the circuit.

An open limit is due to high temp.
Cause, low airflow due to one or more of the following;

• Dirty/restricted air filter.
• Blower not running (bad motor or no power to it).
• Blower not running to speed.
• Dirty/plugged blower wheel.
• Dirty/plugged evaporator coil.
• Closed or blocked registers.
• Dirty/restricted exhaust vent.
• Dirty/restricted heat exchanger.
• Inadequate ducting (wouldn't have just showed up).
• Bad/weak limit.
• Over firing.

Any update?