Coleman Furnace Error Code STEADY ON

On a Coleman furnace, a steady-on LED normally indicates the furnace is operating correctly. If the furnace is in a fault condition and the LED is still steady rather than flashing an error code, it signals an internal control board failure. This condition is not field repairable, and the entire control board must be replaced.

If the furnace is in a fault condition with a steady-on LED, the control board has experienced an internal failure and the furnace is not operating normally. Continuing to attempt operation is not recommended. You should shut the furnace down and have the control board replaced before returning the system to service.

A power reset will not resolve a steady-on internal control failure. Because the fault originates within the control board's own circuitry, cycling power does not repair the underlying hardware problem. The fault will return or persist after a reset, and board replacement is the only supported corrective action.

The internal control failure indicated by a steady-on LED during a fault is not field repairable. There are no component-level fixes available for this condition. The entire control board must be replaced, which is typically a job for a qualified HVAC technician, though experienced DIYers comfortable with furnace electrical work may be able to perform the swap.

Control board replacement costs vary depending on the specific model and labor rates in your area. Parts alone typically range from around $100 to $350 or more, and professional labor can add another $75 to $200 depending on the technician and region. Getting a quote from a licensed HVAC technician before proceeding is a good idea.