Coleman Furnace 1 Amber Flash (CP9C Echelon Modulating)
StatusShown as: One amber flash, two-second pause, repeating
Normal operation with a call for cooling. Not a fault.
Manual wording: “One Amber Flash - Normal operation with call for cooling.”
Documented for: CP9C Echelon modulating furnaces
Likely causes, most common first
- Normal air conditioning operation
When to call a technician
No service needed.
A Coleman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installation Manual - Residential Gas Furnace with ECM Motor, Models TP9C*C, YP9C*C, CP9C*C, LP9C*C (Up to 98% Modulating Multi-position), 681292-UIM-B-1211 (Johnson Controls Unitary Products (Coleman), CP9C*C Coleman Echelon modulating gas furnace (manual also covers the identical TP9C, YP9C and LP9C chassis)) · checked 2026-08-25