Coleman Furnace 2 Red Flashes (CP9C Echelon Modulating)
Soft lockoutShown as: Two red flashes, two-second pause, repeating
The pressure switch is closed while inducer pressure is below the switch setpoint - the switch is closed when it should be open, so the control will not start.
Manual wording: “Two Red Flashes - Pressure switch closed with inducer pressure below pressure switch setpoint (switch is closed when it should be open). Check pressure switch.”
Documented for: CP9C Echelon modulating furnaces
Likely causes, most common first
- Faulty pressure switch stuck closed
What you can safely check yourself
- Turn the furnace off at the service switch for a minute and back on once to see whether the code clears
When to call a technician
A stuck pressure switch is a safety interlock failure. It must be tested and replaced by a technician - never jumper it.
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