Bryant Furnace Code 25.3
Hard lockoutShown as: Major code 25 flashed on the LED (2 short, 5 long); 25.3 on the display
Twinned units are not identical - the two furnaces' program numbers do not match, so the main unit will not operate.
Manual wording: “25.3 TWINNED UNITS ARE NOT IDENTICAL, program #'s do not match. Ensure furnaces are identical (same program #) when twinning. Main unit will not operate.”
Documented for: 926TC, 912SE
Likely causes, most common first
- Two twinned furnaces programmed with different program numbers
When to call a technician
Twinned furnaces have to be reprogrammed to matching program numbers by the installing dealer.
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