Amana Furnace Code 9
Soft lockoutShown as: 9 flashes, then a pause, repeating
Twinning fault. Two furnaces are wired to run together and the control cannot see its partner, so the circulating blowers will not run in step.
Manual wording: “Twinning Fault”
Documented for: Amana AMES80, ACES80 (PCBBF145 control board)
Likely causes, most common first
- Furnace twin terminals not connected together by field wiring
- Isolating relay not used or improperly installed
When to call a technician
Twinning is a field wiring configuration between two furnaces. It needs the installing contractor.
A Amana furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installation Instructions - *MES80 / *CES80 Gas Furnace, Category I - IOG-2021H (Daikin Comfort Technologies (Amana brand), Amana AMES80, ACES80 80% AFUE gas furnaces (PCBBF145 control board)) · checked 2026-08-25