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Bad Blower Motor Symptoms in HVAC

By March 7, 2021HVAC
Bad blower motor symptoms in HVAC

In the southern parts of the U.S., air conditioning is essential.  The temperatures from April into early fall can stay very warm, especially the summer months. Thus needing cool air in the home. Maintaining the HVAC is important before the warm and hot air hits. 

What if you notice there is no cold airflow?  Or there is rattling and humming or the AC fan doesn’t start?  These are all bad blower motor symptoms in an HVAC and need to be looked into right away. Let’s take a look at why this is important, types of blower motors, bad blower motor symptoms, what to do, maintenance of the HVAC unit, and when to call a professional.

Why This is Important

The blower motor is a major part of the HVAC system. It is a spinning fan that blows the conditioned air through the vents and into the home.  It continues to do this until it reaches the temperature in the home that is set on the thermostat. 

The weather gets too hot for the HVAC motor to start having issues, especially during the winter months.  It is important to keep up with the maintenance in the colder months so this does not happen.  In addition, if it does happen, knowing the bad blower motor symptoms in HVAC can help diagnose it.

Two Types of Blower Motors

1. Single Speed

One speed and blows at full force until the temperature in the home reaches the set temperature on the thermostat and then it turns itself off.

2. Variable Speed

This type of blower motor operates at a low or high speed, has better energy efficiency, and keeps a more even temperature in the home.

Bad Blower Motor Symptoms in HVAC

1. Airflow is weak from the vents

This is often one of the first signs or symptoms of a bad blower motor.  If the air is not blowing strong out of the vents, it could mean that something is keeping the air from blowing through the ducts. 

There can be many reasons for this such as there is build up of dirt, bad capacitor, or a motor that is not working properly.

It is important that the blower motor is functioning properly. If it is not, then the indoor coil could freeze over because there is no air being pushed across the coil.

2. Sounds Coming From the Blower

If there is a screeching or squealing sound, this may be the belt is loose or needs lubricating.  A loud banging sound often means that something is broken. 

It can be minor or something major that requires replacing of the blower. Any time you hear loud sounds from an appliance, it is a good idea to turn it off until a professional can take a look and make a diagnosis.

3. Overheating is One of the Symptoms of a Bad Blower Motor in HVAC

If the HVAC system starts to overheat, you will smell something burning.  Some systems will shut down right away when this happens.  If the blower motor starts drawing too many AMPS, then typically the wiring will fail and the breaker may trip indicating there is a problem and a professional should be consulted.

What If the Blower Motor Stops Working

If it stops working, humidity can set in, and then the coils can freeze up.

1. Call a Professional When There are Bad Blower Motor Symptoms in HVAC

If you have any of the issues above, call a professional to do an inspection for you.  This will be important to he/she can see if you actually need a replacement (after the inspection) or if it is a minor fix.  Also, it could be a completely different issue.

2. Replacing the Blower Motor

If the professional deems that the blower motor needs replacing, it is best that they do it.  The blower motor is not something that a homeowner should be replacing. 

The professional is trained to find out: The diameter of the motor, type of drives, rotation direction, voltage, speeds, size of the capacitor, and horsepower.  The professional can give you a quote and ensure it is replaced with the correct motor.

3. Cost to Replace A Blower Motor

When the blower motor can be fixed instead of replaced, you will save a lot of money.  A replacement ranges from $500 to $1500 depending on the size of the unit and where you live.

Maintenance of the HVAC unit
HVAC unit

Maintenance of the HVAC Unit

It is important to maintain the HVAC unit. If you see water leaking from the unit, there could be an issue with the condenser.  One way to avoid an issue is: changing the air filter. Other ways to avoid issues include: making sure the refrigerant is not low, no cracks in the drain pan, and no clogging in the condensate line.

Window air conditioner units also have a blower motor. You can clean this by using 3 to 4 drops of dishwashing detergent and mixing it with water in a water bottle. Then take this concoction and spray it on the fan.  Keeping it clean will keep it working for a long time.

Spring HVAC Maintenance

The spring is the perfect time of the year for maintenance  for the following:

  1. First, pick up debris around the HVAC unit and make sure there are no plants or weeds growing near or into the unit. Doing this several times a year will help.
  2. Clean the condensing unit and the condensation line
  3. Adjust the thermostat- cool in summer, and warm in winter
  4. Keep the attic cool and air flowing easily by cleaning the ductwork
Spring HVAC Maintenance
Spring HVAC Maintenance: Replace weather stripping on windows and doors

 5. Finally, replace weather stripping in the doors and windows to make sure the air is staying inside the home in the warmer months and the heat in the colder months.

If you don’t want to take care of the maintenance, schedule the maintenance twice a year and replace the air filter as often as needed, usually 1-3 months.  Taking care of the unit can hopefully get you the 10-15 years that you should get from the system.

When to Call a Professional

Call a professional when you have issues with your HVAC unit and need help with diagnosis.  Also, have a professional help with the maintenance if it is something you don’t want to take care of.


Staying cool in the hot months is important so paying attention to the sounds and actions of your HVAC unit is essential.  The last thing you want is for issues to happen in the summer. 

Doing spring HVAC maintenance can help take care of issues before they become serious problems and cost a lot of money.  We will inspect your HVAC system during our home inspections in Myrtle Beach, SC. Questions about your HVAC system or in need of our services? Comment below. 

The Rivertown Team

Author The Rivertown Team

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