What to Know When Your AC Needs a Blower Motor Replacement

When your air conditioner stops blowing air, how do you know if you need a blower motor replacement? Truthfully, there can be many reasons that an air conditioner stops working and the blower motor is but one possibility.

Indoor blower motor that failed and requires replacement

This blower motor was replaced and shows how dirt and grime can build up on the fins.

What is a blower motor and where is it located?

A blower motor in your air conditioner refers to the indoor fan that circulates conditioned air around your home. Sometimes it is referred to as a furnace fan. It is located in what is called the air handler if you have electric heat or in your gas-powered furnace. 

Despite being located in your heater, it blows cool air during the Texas heat and warm air during the winter. 

Is There a Difference Between an AC Blower Motor and a Furnace Blower Motor?

An HVAC blower motor refers to the motor that runs the indoor fan to circulate air. It can go by many names: AC blower motor, furnace fan, and even furnace blower motor.

Your heating and cooling system has two fans—a blower motor indoors to circulate air around your home and a fan motor outdoors, which is located in the outside unit. A fan motor’s job is to remove heat after it’s collected from the indoors. Your outside unit may be a condenser or a heat pump. 

What Are Signs of a Blower Motor Failure?

These four signs can sometimes indicate a blower motor failure. If you’re not sure, we recommend hiring a licensed professional HVAC technician who can get to the bottom of the issue quickly. Here’s the most common symptoms that customers report to us.

1. Heating and Cooling System Stops

When your air conditioner or heater stops altogether, it’s usually time to call a professional to diagnose the cause.

2. Weak or no airflow

If you put your hand up to your air vents where air normally blows out and you discover no flow or weak airflow, the cause could be a blower motor failure.

3. Strange mechanical sounds

If you hear strange sounds like a banging sound, it could mean that the motor mount is busted or the fan itself is physically broken. Many times these scenarios happen when the HVAC system is very old or routine maintenance, such as air filters, have not been replaced in a long time. 

When air filters are not regularly replaced, fans can get very dirty over time. When dirt accumulates on the fan and motor, it can make them heavier and add more strain.

Nearly all residential HVAC equipment these days that our company installs, services, and repairs do not have belts that drive the fans anymore. Their blower and fan motors are direct-drive (aka no fan belts).  I haven’t seen any in my customers’ systems in more than a decade. Large commercial equipment, however, often uses motors that are belt-driven. When those start to go out, they can make a whining noise when they start up. 

4. Bad Smell

A few times each season, we get calls from homeowners who have a burning, electrical fire smell, but they don’t know where it is coming from. Usually what happens is that a homeowner calls the Fire Department, but they can’t find a heat signature. This is a textbook blower motor failure situation. It can be pretty frightening, if you don’t know what is going on. 

What Should Your AC Technician Check to Rule Out a Blower Motor Failure?

This blower motor or furnace fan shows the back side of the motor.

This blower motor or furnace fan was replaced in Katy, Texas.

The first thing we recommend doing is to get the blower motor changed out, so we can get your air conditioner going again. Because it’s generally warm to extremely hot for much of the year along the Gulf Coast, being without air is really not what anyone wants. The next step is figuring out the cause of the blower motor failure, so it doesn’t continue to fail.

An HVAC technician may check the following:

1. Air flow

The top reason that blower motors fail is because a heating and cooling system has restricted air flow, something we call “high static pressure.” There are many reasons this can occur.

  1. Air flow can be restricted when air filters are exceptionally dirty and rarely if ever replaced. (If we could tell homeowners one thing – replacing air filters regularly solves many problems!) 
  2. Static pressure readings can be taken if air distribution system is out of balance. An experienced tech can generally hear if your system is out of balance because it has a distinct sound. By taking a static pressure reading, we can tell where in the system the air is getting held up. Your air conditioner has to “breathe in” air (return) before it can blow out (supply) conditioned air around your home. If the flow is restricted, it’s tantamount to having a system in respiratory distress.
  3. Poorly designed air distribution systems can result in air flow imbalances and high static pressure. When we worked on my sister’s system, we had to address the high static pressure by adding more and larger air supply and return registers, so her system could process the proper amount of air.
  4. Experienced HVAC technicians can tell you about specific manufacturers and/or models of furnaces that have had a lot of issues with faulty blower motors. We fix a lot of equipment, so we know which ones to stay away from.

2. Electrical surge problems

Other reasons that cause blower motor failures involve electrical problems with other parts in your heating and cooling system. 

  1. Bad relay or battery (rare)
  2. Bad capacitor 
  3. Bad thermostat
  4. Fan control failure on the PC Board

3. Physical Issues

Loose or dry bearings,  motor mount failure, and broken fins are also possible causes of a blower motor failure. The physical evidence is very obvious.

Why Do Blower Motors Typically Fail?

The number one reason that blower motors fail is that the heating and cooling system’s static pressure is too high. Static pressure comes from the air delivery system, your system of ducts generally located in the attic in our area.

Electrical surges and lack of regular maintenance are other reasons blower motors fail or are not caught early enough. 

What Factors Affect the Price of Blower Motor Replacement?

The cost and availability of the part needed for your air conditioning system are the biggest factors that affect the price of a blower motor replacement followed by the labor to install the part. 

Since about 2018-2019, there have been enormous advances in HVAC motors to make them more efficient along with new federal standards for fan efficiency (Fan Energy Rating or FER). Most if not all the motors installed now are computer-driven blower motors. 

How Blower Motor Technology Is Changing and What It Means for You

The two types of blower motors we use are computer-controlled to keep those fan blades whirling and they are FER compliant. These computer-driven motors start and stop more slowly, which saves energy. The types we use are the following:

  1. Electronically commutated motor (ECM) blower motors look at airflow via RPMs and amp draw
  2. Constant Torque Motor (CTM)  blower motors calculate torque and amp draw; X13 is one brand name.

Permanent Split Capacitor or PSC-type blower motors are being phased out because they are less efficient and they don’t comply with the latest Fan Energy Rating (FER) requirements.

More efficient blower motors are easy on the environment, but new technology comes with a cost. They are not as easy to replace as they used to be because of the technology inside. It used to be the case that we could carry a blower motor that would work as a universal. Universal blower motors that work for any system is a thing of the past. The takeaway for homeowners is it may take a hot minute to procure the exact blower motor designed to work specifically with the brand and model of your HVAC system to meet efficiency and each manufacturer’s requirements. 

How Long Does It Take to Replace a Blower Motor?

In general, it can take two to three hours to replace a typical blower motor. If a highly qualified technician has the part in stock, it can take as little as 1.5 hours. 

Need a Trusted AC Partner to Check Your Blower Motor and Get the Air Flowing Again?

Regular maintenance of your air conditioner is a great way to catch problems like failing blower motors before they cause bigger problems. Contact my wife Summer at 281-495-7830 to get on our schedule for a prompt AC tune-up, inspection, or a repair

Our family-owned and operated business installs, services, and maintains all makes and models of residential and commercial air conditioners, and we are a Ruud ProPartner. We have been serving customers in and around Far West Houston from Memorial Villages through Katy, Fulshear, and Richmond, Texas since 1982. Learn more about how we got started and what customers say about our AC service.