Is My Furnace Blower Motor Bad? (Here Are Some Telltale Signs)

Ossiana Tepfenhart
by Ossiana Tepfenhart

With the weather quickly taking a turn to the colder, the topic of heating quickly becomes a priority. If you’re like most people, having a furnace that’s going bad might be an issue you want to take care of sooner rather than later. One of the more common issues people deal with is a bad HVAC blower motor. But, how can a casual DIYer figure out if a furnace blower motor went bad?

You can tell that your furnace blower motor is bad if there is weakened airflow or if you notice odd noises when it’s on. Furnaces can overheat if the blower motor is bad, and that is an easy way to identify the problem. Energy bills generally increase if there is a problem with the blower motor as well.

Trying to pinpoint the issue that your HVAC system has is difficult, but it doesn’t have to be impossible. This guide will help you figure out if the issues you’re having stem from a failing furnace blower motor.

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Signs Of A Failing Furnace Blower Motor

The furnace blower motor is the part of your HVAC system in charge of distributing the hot air throughout your house. This means that most of the symptoms you’ll notice will have to deal with the speed or airflow of warm air through your home. These signs below can indicate that it’s time to fix your blower motor.

No Airflow

If you don’t have any airflow coming through your vents whatsoever, it’s safe to say that your HVAC blower motor blew out. At this point, the motor is no longer working at all. Should you notice this symptom, then you don’t have much choice aside from getting a new blower motor and repairing your furnace.

Limited Airflow

Though this is not as dire a sign as having no airflow whatsoever, it’s still not a good sign to see. This symptom indicates that your furnace blower motor is going bad and is on the verge of total failure. While it may be possible to fix your motor, this usually indicates that a motor replacement is in order.

Selective Speed Airflow

Selective speed airflow means that you can only get the air to run at certain speeds—most often low ones. Your HVAC system is designed to move air at different speeds in order to give your home a balanced temperature. If you notice that you have selective speed airflow, then you probably have a failing furnace blower motor.

This kind of issue tends to be caused by a failing motor resistor or a failing switch. So, technically, the parts of the motor are still usable. However, you will need to replace the switch or resistor to ensure that the rest of your motor will be able to do their jobs properly.

Strange Noises

This symptom is a little bit rarer to see, but it can still be indicative of a bad blower motor. If you go towards your furnace and start hearing strange sounds coming from the blower’s area, there is a chance that something is impeding the airflow nearby or that you might have a motor with failing bearings.

Blown Fuses/Overheating

Has your furnace been blowing fuses at an alarming rate? Are you having a hard time keeping electricity flowing to the motor? If so, there might be an electrical problem with your blower motor. If the electrical system in your motor goes bad, a surge or dip in power will trigger the fuse to blow in order to prevent a short-circuit.

On a similar note, you should take a look at the actual temperature of the motor. Bad motors tend to overheat, which can potentially cause a fire hazard. Should you notice this issue, you may need to get an HVAC tech to help you out.

High Energy Bills

Any time that you have a failed HVAC part, you will end up seeing a spike in your electric bills. This is normal since your HVAC system is designed to keep bills low. Though high energy bills can be a symptom of other issues with your furnace, the truth is that it should be taken into account when looking at your blower motor, too.

No Fanning

One of the more overlooked symptoms of a bad furnace blower motor is a lack of fanning in your house. Turn your furnace off and switch the thermostat to the “Fan Only” setting. Can you hear the fan going? If so, your blower motor is working fine and you shouldn’t be worried. If not, then chances are that you will need to replace your furnace blower motor soon.

What Causes A Furnace Blower To Go Bad?

It would be amazing to be able to figure out a single reason why HVAC blowers go bad, but that’s not the case. A furnace blower can go bad for a wide range of reasons including old age, electrical failures, bearings failures, or dirt accumulation. If you want to try to prevent your furnace blower from failing prematurely, just maintain your furnace and the surrounding area well.

How Much Does It Cost To Replace A Furnace Blower Motor?

The price varies greatly depending on the type of motor as well as whether or not you are going to be doing the repairs yourself. If you’re handy with HVAC gear, then you might be able to get it done at a cheap price. A simple motor replacement done on your own will cost between $100 to $150.

If you have a more upscale furnace blower motor, the DIY repair can still get higher. A DIY furnace blower motor replacement for an upscale blower can cost between $500 to $1800, even if you don’t hire a professional. That price tag is just for the furnace blower motor itself.

Going the professional route quickly becomes more expensive. On average, homeowners will pay anywhere from $300 to $700 for a typical repair. Top of the line, multi-speed furnace blower motor replacements can easily exceed $1,500 or more. Needless to say, this can be a serious financial peril for some families.

How Long Should Your Furnace Blower Motor Last?

Even with excellent maintenance, there will come a time where your blower motor will fail. A furnace blower motor usually lasts about the same amount of time as the furnace. So, you should expect your furnace blower motor to last between 10 to 20 years on average. The more reliable the brand, the more likely it is to reach the 20-year mark without serious problems.

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Related Questions

Is it possible to upgrade your furnace blower motor?

Like with many other parts of your HVAC system, it is both possible and often advisable to give your furnace blower motor an upgrade. Newer models are more energy-efficient and are designed to provide premium heating throughout the home.

Should I run my furnace fan constantly?

Though it might contribute to wear and tear, it can be advisable to use your furnace fan on a near-constant basis. Keeping your fan on will help improve air circulation throughout your home, giving you a warmer and more even temperature throughout your home. If you want to keep your home energy-efficient, set your fan to AUTO instead.

How many CFM does a furnace fan move?

On average, you can expect your fan to move at least 1,000 cubic feet per minute.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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