Payne Furnace Code 10.1
Hard lockoutShown as: Rapid flashing LED; 10.1 on the 3-digit display
L1 polarity fault - the polarity of the incoming 115 V power is reversed.
Manual wording: “10.1 L1 POLARITY FAULT - Rapid flash LED. Polarity of incoming 115V power is reversed.”
Documented for: PG80MSU
Likely causes, most common first
- Line voltage (115 V) hot and neutral reversed at a junction
- Improper low-voltage (24 V) transformer phasing on twinned units
When to call a technician
Fixing 115 V polarity requires opening junction boxes on live wiring - call a licensed technician or electrician.
A Payne furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- PG80MSU: Installation, Start-up, Operating and Service and Maintenance Instructions (Payne, PG80MSU 80% multipoise gas furnace with 3-digit display and pressure transducer) · checked 2026-08-25