A furnace blower motor is a crucial component of any functioning forced-air heating, ventilation and air conditioning (HVAC) system. It keeps your home cozy in winter and cool in summer, and you’ll notice right away if it stops working.

Get to know your blower motor before trouble hits with the help of two industry experts, Joshua Smith from Berkshire Heating and Air Conditioning and Alexander Siv from Amherst Plumbing and Heating. Learn all about furnace blower motors, how to tell if yours is going bad, and how much it costs to have it replaced.

What Is a Furnace Blower Motor?

A furnace blower motor turns the blower fan to distribute conditioned air through ductwork in a forced-air HVAC system. “It’s the main mechanism to get the air circulating through the ductwork and through your house,” Siv says.

Only forced-air systems rely on a blower motor to heat or cool your home.

What Is the Life Expectancy of a Furnace Blower Motor?

Ten to 20 years, on average. “Motors are designed by the manufacturer to live as long as the life of the appliance,” Smith says. This can be 12 to 15 years, or 18 to 20 years with proper maintenance and care, according to Siv.

How To Tell if Your Furnace Blower Motor Is Bad

• Grinding or screeching sound: “The bearings in the motor can start to go bad or get dirt stuck in them,” Smith says. This can cause the motor to make these sounds.
• Burning smell: If the motor is beginning to fail, “sometimes you’ll get an electrical burning smell before it goes,” Smith says.
• Short run times: If the furnace repeatedly powers on and off quickly, this can be a sign the blower motor isn’t working. “Without the blower running, the furnace gets too hot and shuts itself down,” Smith says. “Then it cools down and restarts again, gets too hot and shuts down again.” Siv says this cycle is a common first sign the motor is having trouble. “People don’t realize it’s happening, and eventually it will seize and stop working,” he says.
• No air flow: If there’s no air blowing through supply vents, Smith says, “one cause could be a bad blower motor.”

Are Furnace Blower Motors Universal?

Yes and no.

There are universal motor replacements for electric and gas-powered furnaces. However, which one you buy will also depend on your existing motor’s horsepower, voltage and rotations/revolutions-per-minute (rpm).

“You have to match everything up,” Smith says, “You can’t just walk into a store and ask for a universal blower motor.” You must know the specifics of the motor you are replacing.

What Happens if the Furnace Blower Motor Goes Out?

If it stops working completely, conditioned air can’t move, and the furnace or AC will not heat or cool as directed.

How To Test the Furnace Blower Motor

Homeowners can conduct a simple test. Siv says to switch your thermostat to ‘fan’ mode, then feel your supply vents for air flow. If there’s no air, “that’s a sign your blower motor may not be working,” he says. Convey this information to an HVAC pro who can diagnose the problem.

Further testing of the blower motor’s electrical functioning should be conducted by a pro technician with specialized tools. This is not a regular maintenance task, but is usually done to diagnose a problem with the furnace.

How Much Should It Cost to Replace a Furnace Blower Motor?

“An average blower motor can cost anywhere from $500 to $1,500,” Smith says, “The more horsepower your motor has, the more expensive the replacement will cost.” This price range includes parts and labor.

Residential blower motors are usually one-quarter, one-third or one-half horsepower (hp). A one-half hp motor will cost more than a one-quarter hp motor, but labor costs are the same regardless of motor size.

Can I Replace the Furnace Blower Motor Myself?

No. That’s a job for an HVAC pro.

“It’s not something I recommend [for DIYers],” Smith says. Siv agrees. “It requires a lot of tools and knowledge about the whole system,” he says, “Furnaces are complex equipment.”

Diagnosis alone is a nuanced and complicated process. “It could be all kinds of stuff that causes a blower motor to stop working,” Siv says. “It could be a relay switch or a safety switch that’s not connected.”

HVAC pros also carry the right tools to do the job. “Just to get the motor wheel off the blower, you’ll need special tools that a typical homeowner just won’t have available,” Smith says.

About the Experts

• Alexander Siv owns Amherst Heating and Plumbing in Amherst, Massachusetts. He has a master plumber’s license in Massachusetts and more than 10 years of plumbing experience.
• Joshua Smith is operations manager at Berkshire Heating and Air Conditioning in West Springfield, Massachusetts. He has more than 20 years of HVAC experience and currently holds a Massachusetts oil burner and refrigeration license.