Carrier and Bryant 10 Error Code: L1 polarity fault (rapid flash)
Updated October 2026 · Sourced from Carrier and Bryant documentation
🛑 Turn it off and call a licensed pro
The control reports an L1 polarity fault. The status LED flashes rapidly and the furnace will not operate.
Is it safe to keep running? No. Turn it off and get it checked. Turn the furnace off at the breaker and call a licensed technician or electrician to correct the 115-V wiring polarity.
10 at a glance
| Code / how it shows | Meaning | Applies to |
|---|---|---|
| 10 Also: 10.1 Rapid-flash status LED; display shows 10.1 | L1 polarity fault (rapid flash) | Bryant 926TC two-stage variable-speed ECM multipoise condensing gas furnace |
🛑 Stop and call a licensed pro if
- Turn the furnace off at the breaker and call a licensed technician or electrician to correct the 115-V wiring polarity.
- You smell gas. Leave the house, do not touch switches, and call your gas utility from outside.
- Flame rollout, limit or pressure switch codes that come back after one reset.
- Anything involving the control board, gas valve, flame sensor, igniter or venting.
- A carbon monoxide alarm sounds. Get everyone outside and call 911 or the fire department.
Safe first steps for any Carrier and Bryant code
- Count the LED flashes through the blower door window before you switch anything off. Cutting power can clear the code.
- Replace or clean the furnace air filter.
- Check the thermostat: correct mode, set above room temperature, and fresh batteries.
- Make sure the furnace power switch and breaker are on. If the furnace has locked out, turning the power off and back on once restarts it.
- Make sure the gas valve is in the ON position, following the lighting instructions on the furnace label only.
- On high-efficiency furnaces, look at the outside vent and intake pipes for snow, ice, leaves or nests (look only, do not take pipes apart).
Source: Bryant 926TC Installation, Start-up, Operating and Service and Maintenance Instructions, Service Label (Status Code Table), p.56. Codes are series-specific, so your unit's own manual is the final word. Reviewed October 2026.
Shaun Cain · Certified HVAC & Refrigeration Technician · Ask an HVAC technician
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