Furnace part
Blower motor (ECM)
The blower motor moves air across the heat exchanger and through the ducts in heating, cooling and continuous-fan modes. Modern furnaces use electronically commutated (ECM) motors; failures show as no airflow, weak airflow, noise, or RPM codes on the control.
ECM motors come in two flavours: constant-torque motors run efficiently at installer-selected speeds, while constant-airflow motors measure and hold the airflow the control requests as filters load and dampers move. Communicating furnaces use the constant-airflow type.
Because ECM motors report speed to the control, failures often log an RPM code (for example, no-RPM or failed-to-reach-speed codes on the controls documented on this site).
Signs this part is involved
- No airflow at all, with the control logging blower RPM codes
- Squealing or grinding from the blower area
- Weak airflow at registers after the filter checks out
- Blower that runs at the wrong speed or stops mid-cycle
Related fault codes
- Carrier 59TP6C status code 15.1: lockout - no blower rpms detected
- Carrier 59TP6C status code 41: blower RPM not detected
- Carrier 59TN7A status code 41: blower RPM not detected
Codes are documented per controller; check the model number on your rating plate before comparing. Not sure which control you have?
Related
- ComponentBlower motor
- SymptomWeak airflow from registers
- SymptomFurnace making abnormal noise
- ServiceGas Furnace RepairFurnace repair in Greater Vancouver, diagnosed before parts are replaced
- ServiceFurnace MaintenanceAnnual furnace maintenance that checks what actually fails
- GuideECM versus PSC blower motors: what the motor actually does
Questions people ask
Is the blower motor covered by warranty?
It is a part, so the parts warranty applies on a registered furnace subject to the cause. Labour is usually separate, and water or electrical damage from outside the furnace is typically excluded.
Can a dirty filter damage the blower motor?
A loaded filter restricts airflow and makes the blower work harder; over time that stresses the system. Filter changes are the cheapest protection for the motor.
Not sure whether the blower motor (ecm) is your problem?
BC Wide diagnoses by testing, not by part swapping. Tell us the model number from the rating plate and what the furnace is doing.