If your furnace won't turn on, the problem might be a bad draft inducer motor. When a draft inducer motor starts to go bad, you might hear unusual noises coming from your furnace. Once the motor fails, the furnace may try to start up a few times, but eventually, your furnace shuts down and won't start up again. You might be able to tell by looking at the control board codes that the problem is with the inducer motor.

The furnace inducer motor is the first thing to start when the thermostat calls for heat, so if it fails, the rest of the furnace won't kick on. To better understand why your furnace may not be starting, here's the purpose of a furnace draft inducer motor, what can go wrong with it, and the furnace repairs you may need when it malfunctions.

The Draft Inducer System Flushes Out Air

The draft inducer system is wired to the thermostat. The system consists of a fan and a motor that operates the fan. Some furnaces also have a capacitor to help operate the motor. When the thermostat signals for heat, the motor spins the fan so fresh air is pulled in and old air from the previous combustion cycle is flushed out of the combustion area and sent up the flue.

This has the effect of cleaning old air out of the combustion area, so when the furnace ignites the gas burns fresher air and the exhaust is cleaner. Once the combustion sequence starts it sustains the airflow and the inducer motor shuts off.

The Motor Can Go Bad

Problems with the draft inducer motor are fairly common. The bearings or other parts in the motor can wear out due to age. Also, if wiring from the thermostat is bad or if the thermostat is malfunctioning then the motor can be affected. If the fan has issues such as a loose blade, that can also affect the motor, so when you hire a furnace repair service, they will need to examine it to track down the exact cause of the problem.

Furnace Repairs Include Replacing Bad Parts

If the problem is minor, such as a loose part, repairs might be possible. For example, if the problem is with the capacitor, replacing it might solve the problem. The furnace repair technician can test the parts with a multimeter to figure out which one needs to be replaced.

If a replaceable part isn't the issue, the entire motor will likely need to be replaced. A bad motor will be disconnected from the wiring and the furnace and pulled out. The motor is right behind the furnace panel so it's easy to access, but it's connected to other parts and several wires, so it has to be taken out and put back in carefully.

The furnace repair technician will put in a new motor that will work with your model of furnace. After attaching the wires, vent, and other parts as needed, the motor will be tested for proper operation. Your furnace should start working normally once the new inducer motor is in place.