Coleman Furnace 10 Red Flashes (CP9C Echelon Modulating)
Safety faultShown as: Ten red flashes, two-second pause, repeating
Gas valve circuit shorted.
Manual wording: “Ten Red Flashes - Gas valve circuit shorted. Check gas valve wiring. If correct, replace gas valve.”
Documented for: CP9C Echelon modulating furnaces
Likely causes, most common first
- Shorted gas valve wiring
- Failed gas valve
What you can safely check yourself
- If you smell gas, leave the house and call the gas utility from outside
When to call a technician
A shorted gas valve circuit is a gas-safety fault. Call a licensed technician and do not keep cycling the furnace.
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