Why Is My Furnace Blower Motor Squeaking/Squealing?

A persistent squeaking noise coming from your furnace’s blower motor while it’s running can get really annoying after just a few minutes.

So, what’s causing it? Well, that squealing noise usually indicates too much friction between moving parts.

Two main places to check if your furnace is squeaky include:

  • The blower motor bearings
  • The blower motor belt

Unless you know what you’re doing, we suggest leaving the repair to a professional. But, if you want to take the DIY route and have a pretty good grasp of how your furnace operates, read on. 

We’ll give you the information you need to fix these two components on your own.

Check the blower motor bearings

Bearings are the ring-shaped metal devices that slide over each side of the blower motor shaft. 

You see, when you turn your furnace fan on, that blower motor spins round and round. The bearings are there to “bear” the amount of friction and stress the motor shaft receives so that it can spin smoothly.

However, when those bearings wear out or lose their lubrication, you’ll hear a screeching noise as the metal components of the bearing and the motor shaft grind against each other.

Eventually, bad bearings that aren’t replaced can ruin the motor shaft. So act quickly if you hear that tell-tale squealing noise.

What to do

Visually inspect your motor bearings for damage. Aside from the squeaking noise, there’s no sure way to know if your bearings are bad without visually inspecting them. 

Because your furnace is hard-wired into your home’s electrical system, we suggest you leave this visual inspection to a professional

However, if you know what you are doing, you can follow these step-by-step instructions on replacing your motor blower bearings.

Check the blower motor belt

Most older furnace blower fans are belt-driven. As the belts wear down or become misaligned, they’ll start to squeak.

What to do

If you know that your furnace is an older model that is belt-driven, you can visually inspect the belt for issues.

To check for a worn out fan belt, follow these steps:
Step 1: Cut power to the furnace at the circuit breaker.
Step 2: Open the blower motor panel (you’ll need to use a screwdriver to remove the screws).
Step 3: Locate the belt and check for cracking, ripping or any separation on the belt.

If your belt is damaged, you can replace the blower motor belt on your own following these instructions.

Don’t want to deal with the hassle of replacing the belt yourself? Contact a professional to replace your blower belt

Note: We suggest providing your furnace make and model beforehand so the tech can bring the appropriate replacement parts (and save you the cost of an extra service call).

In need of a Minnesota HVAC tech?

If you’re still unsure what’s causing your furnace’s squeaking sounds, we’re here to help.

Just schedule your appointment with us today and we’ll send over a professional right away to fix the unit.

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