How Do I Know if My Furnace Inducer Motor Is Bad? (Troubleshooting)

If you want to keep your home’s furnace operating at a high rate of efficiency while preventing gas build-up, the inducer motor is key. These motors have an impressive lifespan, but can still go bad leaving your furnace inoperable. In this guide, we’re going to discuss inducer motors and their importance along with some tips on how to diagnose problems.

What is a Furnace Inducer Motor?

Before you can begin to diagnose problems with a draft inducer motor, we recommend learning a little more about the part itself. Found inside a furnace near the heat exchange, an inducer motor on a furnace has one job. It’s designed to remove leftover gasses that may have become trapped in the furnace during the previous cycle.

While a furnace draft inducer blower like the Goodman FB-RFB501 may look complicated, they are actually simple by design. Before each heating cycle, the inducer motor starts a small fan 30 to 60 seconds before the system ignites. Any remnants of gasses left behind are expelled before the furnace. While the fan and housing are important, they are useless without the inducer motor.

Why Draft Inducers Motors are Important

When the draft inducer blower is working properly by removing excess gas and purging the heat exchanger on a furnace, several beneficial things occur. The first involves safety. Having toxic fumes built up in a vent pipe is never ideal, especially before you attempt to fire up a furnace. Draft inducers remedy that so you won’t have to worry about leftover gasses potentially igniting in the vent.

A high-quality draft inducer motor also allows a system to be as efficient as possible as clean combustion keeps soot from building up on burners. This ensures the fan operates as it should so the air moving through the system is clean which improves efficiency. They work in conjunction with pressure switches for safety but can fail for a variety of reasons.

Motors in this class are designed to last, so it’s not uncommon to find factory components in a system for 15 to 20 years. Unless the inducer motor has been repaired in the past, the most common cause of failure is age, heat or sudden spikes in voltage.

Signs of a Bad Furnace Inducer Motor

Has your heater ever just refused to start? While that can occur for a dozen different reasons, a bad condenser motor falls into that category as well. By design, a control board may recognize an issue and stop sending voltage to the inducer motor if it fails to start after several attempts.

Bad pressure switches can have this effect as they are tied directly to the inducer motor and fan, but Odd noises have always been a sign of trouble with inducer motors as well. When functioning properly, you may hear a slight noise when it comes on, but should not hear anything unusual.

That includes rattling, knocking, humming, and tapping noises that may emanate from a system with a faulty inducer motor. Anything that’s become loose or an unbalanced wheel can cause vibrations, which lead to noise and potentially other issues within your system.

If the unit turns on, but the blower doesn’t function, there are a few further steps you can take before making a service call for an HVAC technician.

Digging deeper…

Whether you notice an odd noise and want to diagnose the issue further or simply want to rule anything out before calling a tech, you can take the inspection a step further. To do this, you’ll want to ensure you have easy access to the furnace and will need to cut power to the system before removing any side panels.

Once the power is off, remove the access panel and locate the blower motor. If the motor feels hot to the touch on its side, that could be a sign of failure. The inducer motor may be attempting to start, but has begun to overheat in the process. Aside from any obvious signs of damage to capacitors or other components, there is only one other thing you can check.

While being cautious of fins and other metal edges that could be sharp, try and move the squirrel cage. Does it spin freely or stays stuck in place? If it’s the latter, the motor could be defective. The same process is used to find a bad start capacitor in an HVAC system and works for furnace inducer motors as well.

Inducer Motor Cost and Replacement

Some homeowners may prefer to leave the fine details to the professionals when it comes to the cost of an inductor motor replacement, while others prefer to go in with a bit more knowledge. The first thing to know is that if the motor is bad, rebuilding it may not be an option unless it’s made by Carrier or Bryant.

That means more often than not, you’ll need to pay for a completely new inducer motor along with the installation. Handy homeowners can accomplish this, although it’s something most homeowners will choose to forgo. As you can see from the video below, it’s not the easiest DIY project in terms of furnace repair.

On average, you can expect to pay between $25 to $450 for the inducer motor depending on the style and brand. Labor can run anywhere from $200 to $600 as factors like access come into play along with your general location. In our research, we found most homeowners pay around $250 to $800 for a professional to replace an inducer motor from start to finish.


Diagnosing issues with a furnace inducer motor is a bit different than dealing with a faulty AC capacitor, but both problems should be addressed swiftly on any furnace or air conditioning system. When you know the motor on the draft inducer is bad, you’ll want to check out these tips in our guide to condenser motor replacement.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.

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