Coleman Furnace: 11 Flashes
A Coleman furnace LED pattern starting with 11 flashes matches 2 documented codes: 11 red flashes, 11 red flashes (CP9C Echelon modulating). Watch the full pattern (short vs. long flashes) to tell them apart — all 2 are explained below.
Code 11 red flashes: The main limit switch opened and stayed open for more than five minutes, which the control reads as a failed blower
The main limit switch opened and stayed open for more than five minutes, which the control reads as a failed blower. It enters a hard lockout that only a power cycle clears.
Manual wording: “11 RED FLASHES: This indicates that the main limit switch has opened its normally-closed contacts and has remained open for more than five minutes. This condition is usually caused by a failed blower motor or blower wheel. The control will enter a hard lockout...”
Documented for: TG8S, TGLS, TG9S, TM8X, TMLX, TM9X, TM8T, TM9T, TM8V, TM9V
Likely causes, most common first
- Failed blower motor
- Failed or seized blower wheel
What you can safely check yourself
- Check and replace the air filter
- Open blocked supply registers and clear anything covering the return grille
- Turn the furnace off at the service switch for a minute and back on once after the airflow problem is fixed
When to call a technician
A blower motor or wheel failure is a technician replacement job. If the code returns after one reset, stop resetting it and call for service.
A Coleman furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Sources
- Installation Manual - Residential Gas Furnace, Models TG9S*MP, GG9S*MP (95.5% AFUE Single Stage Multi-position), 364861-UIM-G-1211 (Johnson Controls Unitary Products (Coleman), TG9S*MP, GG9S*MP 95.5% AFUE single-stage multi-position gas furnaces) · checked 2026-08-25
- Installation Manual - Residential Gas Furnace, Models TG8S*MP, TGLS*MP, GG8S*MP, GGLS*MP (Single Stage Multi-position / Low NOx), 356485-UIM-G-1211 (Johnson Controls Unitary Products (Coleman), TG8S*MP, TGLS*MP, GG8S*MP, GGLS*MP 80% AFUE single-stage gas furnaces) · checked 2026-08-25
- Installation Manual - Residential Gas Furnace, Models TM8X*MP, TMLX*MP (Single Stage Multi-position / Low NOx with High-Efficiency Motors), 437642-UIM-F-1211 (Johnson Controls Unitary Products (Coleman), TM8X*MP, TMLX*MP 80% AFUE single-stage gas furnaces with high-efficiency motors) · checked 2026-08-25
- Installation Manual - Residential Gas Furnace, Models TM9V*MP (Two Stage Variable Speed ECM), 701379-UIM-B-1211 (Johnson Controls Unitary Products (Coleman), TM9V*MP two-stage variable-speed ECM gas furnaces) · checked 2026-08-25
Code 11 red flashes (CP9C Echelon modulating): Main blower failure
Main blower failure. The main limit opened and did not reclose within five minutes, which the control reads as a failed blower motor or blower wheel.
Manual wording: “Eleven Red Flashes - Main blower failure - This flash code occurs when the main limit opens and fails to reclose within five minutes, indicating that the blower motor or blower wheel has failed.”
Documented for: CP9C Echelon modulating furnaces
Likely causes, most common first
- Failed blower motor
- Failed blower wheel
What you can safely check yourself
- Check and replace the air filter
- Open blocked supply registers and clear the return grille
When to call a technician
Blower motor or wheel replacement is a technician job. Stop resetting the furnace if the code returns.
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
Full page for Coleman code 11 red flashes (CP9C Echelon modulating)