10 Symptoms of a Faulty Furnace Blower Motor


Furnaces are a vital and basic need for surviving the harsh winters in North America. They heat up your house, providing you with a warm temperature.

But there may come a day when even an efficiently maintained furnace can fail to produce that much-needed heat. A faulty furnace blower motor is among the chief reasons why your furnace could not be working as it’s supposed to. Click the following link https://andersonair.com/how-to-check-a-furnace-blower-motor/ to learn how to verify if your furnace blower is the problem.

Furnace blower motors are the furnace components that push the heated air throughout the house ductwork and vents, warming up your house to the desired temperature. So once the furnace blower motor becomes faulty, it will fail to blow the warm air throughout the house. When this occurs, you will likely need to contact a reputable furnace repair Henderson company.

There are three types of blower motors. The single-speed and multi-speed furnace blower motors and the variable-speed blower motor. A single-speed furnace blower motor blows air at only one speed. A multi-speed does it at two speeds and at full capacity when it’s operating, turning on and off according to the thermostat’s instructions.

On the other hand, a variable-speed blower motor operates at both lower and higher speeds. And this enables you to enjoy a more even temperature throughout your house and better energy efficiency.

So, how can you identify if your furnace blower motor is not working properly? Below are the 10 bad furnace blower motor symptoms.

1.      Overheating and Burning Smell

When the furnace blower motor overheats, it produces and causes a burning smell to come out of your vents. Once you smell a burning smell from your furnace, it could be a sign that you have a faulty furnace blower motor.

The burning results from the furnace overheating, which is sometimes a result of dirt buildup on the blower motor. When the dirt builds up, it prevents the blower motor from efficiently distributing the air. And this causes the hot air and pressure to build up in the furnace, causing overheating.

2.      Weak Airflow

The furnace blower motor is responsible for pushing air through the vents. So if you test your vents and don’t feel air coming through, then there could be a problem with your furnace blower motor.

A faulty furnace blower motor cannot circulate air through the duct system and efficiently force it through the vents.

3.      Clogged Vents

Although clogged air vents are a cause of faulty furnace blower motors, they are also among the symptoms of a bad blower motor on a furnace in your home.

Once vents are clogged, this means that there is a lot of dirt on the internal furnace components, meaning that dirt has covered the furnace blower motor and is causing great resistance for the blower motor to effectively circulate air from the furnace into the vents and throughout the house.

4.      Spike in Power Bills

If you notice that your bills have suddenly gone high, then the problem could be with your furnace blower motor.

A faulty or old furnace blower motor uses more power to push air through the vents, increasing power usage.

5.      Weird Sounds Coming From the Furnace

Strange sounds are another sign your furnace blower motor is faulty. If you hear a clunking or vibrating sound, it could mean that parts of your blower motor are loose or disconnected.

6.      No Air At All From the Vents

Although this could be a problem with the thermostat, this is also one of the bad furnace blower motor symptoms.

When your furnace blower motor completely breaks down, it stops working and blows no air. The result is that there is no air circulation, and no air is blown through the vents.

If this persists, it could lead to the furnace overheating, breaking down, or shutting down. So, call your HVAC technician in case this happens.

7.      The Circuit Breaker Keeps Tripping

A faulty furnace blower motor can also trip its circuit breaker. A blower motor that had stopped working because its parts can no longer move (seized up) is bound to trip a circuit breaker. So, when your furnace keeps going off, it could be one of the symptoms of bad furnace blower motor. And if this is so, your furnace blower motor needs replacement.

Note: A faulty or bad capacitor can also trip your circuit breaker. So, ensure to check the capacitor first before the furnace blower motor to avoid wrong diagnoses.

8.      The Furnace Starts and Stops Randomly

Suppose the furnace has regular maintenance and has been working for a long time but suddenly stops working. It simply means that the furnace blower motor is past its lifespan.

A furnace blower motor is built to last as long as its furnace (10-20 years). But when it works more than it’s supposed to, it will eventually give out.

9.      Intermittent Operation

Irregular operation of the furnace is one of the main bad furnace blower motor symptoms.

When your furnace operates well, sometimes, and other times it stops altogether. Or when it sometimes blows out warm air and other times it doesn’t at all, then there could be a problem (defect) with your furnace blower motor.

The intermittent operation results from the blower motor being full of dirt, having broken or faulty wires, a defective limit switch, a faulty capacitor, or a poor voltage supply.

Test the limit switch with a multimeter when you clean the blower motor coils. And if this fails to work, then the whole furnace blower motor could be faulty and in need of replacement.

10.  Furnace Doesn’t Meet Thermostat Temperature

As long as the furnace blower motor is broken, the furnace won’t be able to meet the set thermostat temperature, however much the furnace runs.

So, when this happens, it could signify that your furnace blower motor is faulty.


A furnace is as good as its blower motor. The more efficient the blower motor, the more efficient your furnace. And you can enjoy the best your furnace has to offer with regular maintenance by a professional.


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