Bryant Furnace Code 33.1
Soft lockoutShown as: 3 short flashes, 3 long flashes
A switch has opened in the main limit circuit - the limit or flame rollout switch is open. The blower runs 4 minutes or until the switch remakes. If the switch stays open longer than 3 minutes the code becomes lockout 13.
Manual wording: “33.1 A SWITCH HAS OPENED IN THE MAIN LIMIT - Indicates the limit or flame rollout is open. Blower will run for 4 minutes or until open switch remakes whichever is longer.”
Documented for: 926TC, 912SE
Likely causes, most common first
- Dirty filter or restricted duct system
- Loose blower wheel
- Defective switch or connections
- Defective blower motor
- Improper gas input adjustment
What you can safely check yourself
- Check and replace the air filter - a clogged filter is by far the most common cause
- Make sure supply registers and return air grilles are open and unblocked
- Make sure the furnace door is fully seated
When to call a technician
If the code returns after a filter change, the limit or rollout switch is tripping for a reason a technician must find. The flame rollout switch requires manual reset and must never be reset without diagnosing why it tripped.
A Bryant furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation, Start-up, Operating and Service and Maintenance Instructions - 926TC (Bryant Heating & Cooling Systems, 926TC Preferred Series two-stage, variable-speed ECM multipoise condensing gas furnace) · checked 2026-08-25
- Installation, Start-up, Operating and Service and Maintenance Instructions - 912SE (Bryant Heating & Cooling Systems, 912SE Legacy Line 92% single-stage condensing gas furnace) · checked 2026-08-25