If you’re looking for help fixing your Coleman furnace, look no further! Our comprehensive Coleman furnace repair guide will explain common issues, provide troubleshooting tips, and show you how to read your model’s error codes.

CODE: Slow green flashing
PROBLEM: Coleman furnace is operating normally.
FIX: N/A

CODE: Slow amber flashing
PROBLEM: Normal operation with a call for heat.
FIX: N/A

CODE: Steady on red
PROBLEM: There’s a control failure.

CODE: Rapid red flashing
PROBLEM: There’s a twinning error with incorrect 24V phasing.
FIX: Check the twinning wiring.

CODE: Rapid amber flashing
PROBLEM: There’s a low flame sense current.
FIX: Check and clean the flame sensor. If it’s still an issue, check for proper gas flow.

CODE: One red flash
PROBLEM: A flame’s present with the gas turned off.
FIX: Check the gas valve. It could be leaky or slow closing.

CODE: Two red flashes
PROBLEM: Pressure switch is stuck in the closed position.
FIX: Check if there is a faulty pressure switch or miswiring.

CODE: Three red flashes
PROBLEM: Pressure switch is stuck in the open position.
FIX: Check if there is a faulty inducer, a blocked vent pipe, a broken pressure switch hose, or a faulty pressure switch.

CODE: Four red flashes
PROBLEM: Limit switch is stuck while open.
FIX: Check for a a dirty filter, an improperly sized duct system, an incorrect blower speed setting, or a faulty blower motor.

CODE: Five red flashes
PROBLEM: Rollout switch is stuck while open.
FIX: The rollout control is manually reset. Therefore, if it has opened, then check to see if the inducer is operating properly or there is an issue with the primary heat exchanger.

CODE: Six red flashes
PROBLEM: Pressure switch cycle has locked out.
FIX: The furnace will lockout for one hour and then reset.

CODE: Seven red flashes
PROBLEM: There’s an ignition lockout due to too many retries.
FIX: The flame couldn’t be established, check for a faulty gas valve, a dirty or defective flame sensor, a faulty hot surface ignitor, or a problem with the burner.

CODE: Eight red flashes
PROBLEM: There’s an ignition lockout due to repeated power recycles.
FIX: Check if there is low gas pressure, a dirty or defective flame sensor, or a faulty gas valve.

CODE: Nine red flashes
PROBLEM: There’s a grounding or line polarity issue.
FIX: Check the polarity at both the furnace and branch.

CODE: Ten red flashes
PROBLEM: Gas continues to flow with no call for heating.
FIX: Check on the gas valve and the gas valve wiring.

coleman furnace codes

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