Your furnace blower is responsible for blowing hot air into your ductwork. After years of usage, your furnace blower can start making an annoying noise.
You can ty to quiet your noisy furnace blower by doing the following:
- Repace the blower fan bearings
- Clear the blower fan
- Oil the blower motor
- Replace the blower fan blades
- Tighten the set screw
- Check if the motor mount is loose
- Use sound insulation
- Replace the motor fan
- Check the belts
- Call a pro for an inspection
- Reduce the fan speed
Below you’ll find out how to quiet a noisy furnace blower.
Let’s get started.
How to Quiet a Noisy Furnace Blower
1. Replace furnace blower fan bearings
Your blower fan has bearings that provide lubrication and helps everything run smoothly.
As time goes on, your ball bearings can wear out and start to cause resistance inside the furnace blower.
You may also hear a noise that’s being created by your ball bearings which is intensified by the ductwork you have in your home.
The best way to fix worn-out bearings is to install new ones.
2. Clean the blower fan
If your furnace blower is making a loud humming noise, this is an indication that there is a lot of dust on the blower fan.
The best way to fix this issue is simply to clean the blower fan and dust off all the caked-on dust that’s wearing it down.
3. Oil the blower motor
Oiling your motor will help prevent any high pitched squealing that you may be hearing. This can also be an indication that your belt is loose.
4. Replace the blower fan blades
As your blower fan works year after year, the fan blades can get damaged and start to make a banging sound.
If you hear a banging sound coming from your furnace you should get it looked at immediately. The banging noise can lead to further damage to your furnace.
The best way to fix this worn-out blades is by replacing your old blower fan with a new one.
5. Tighten the set screw
The furnace blower is held by a set screw.
If the screw becomes loose, then your furnace can start to make a rattling noise. Fix this issue by tightening the screw and seeing if that fixes the rattling noise.
6. Check if motor mount is loose
If you hear a scraping sound, this is due to loose parts inside of your furnace. This could be your motor mount, wheel, or even a loose pully.
Before you do an inspection, it’s best to turn off your furnace as some of these parts will be moving.
If you find any of them are loose, they likely need to be replaced.
While the installation process isn’t difficult, an HVAC technician can make your life much easier with a quick check-up.
7. Use sound insulation
You can try to insulate the room that your furnace is in if you can’t figure out the problem.
By using special products that wrap your ductwork, a sound barrier will help prevent any sound from escaping.
You can also opt to use a special foam called melamine around the blower intake to aid in insulting your furnace blower.
8. Replace the motor or fan blades
If you’ve tried everything, it may make sense to just replace the furnace blower motor entirely.
While this is a disappointing result, it will fix the problem outright and you won’t need to worry about a noisy furnace blower any longer.
9. Check the belts
If your furnace has a belt drive, then it can be the source of a squealing noise.
If you hear such a noise, ensure that it’s in the right place, and if the squealing noise continues, you may need to replace the belt altogether.
10. Call a professional
If you’ve tried everything and nothing seems to help the furnace blower noise, your best bet is to call an HVAC repair man to help diagnose your furnace blower motor.
11. Reduce the fan speed
Your furnace may just be noisy as the furnace fan speed is set too high.
Try reducing the furnace fan speed to see if it helps reduce the noise level.
How to Lubricate Your Furnace Blower?
To lubricate your furnace blower, you’ll need to add two to three drops of motor oil into each port.
Before you proceed, you should turn off the circuit breaker to ensure that your furnace is completely off.
The blower motor assembly is near the bottom of your furnace. You may need to remove the cover with a wrench.
Remove the set screw of your furnace blower motor housing, and then detatch any bolts connecting the housing to the internal motor.
You can now take out the motor from its housing.
Find each oil port on the motor which should be marked.
At this point, drop two or three drops of oil into each port. Your manufacturer may require more or less oil, so it’s always best to check with your furnace’s manual.
Final Thoughts
Your furnace blower blows hot air through the ductwork and into the rooms of your home.
A noisy furnace blower can be an indication that something is wrong and needs to be inspected.
A whistling noise may also be an indication that air is escaping from your blower motor or that it’s too large for your furnace.
While a loud noise can be annoying, it may be that your furnace is operating normally and there isn’t anything to be worried about. The best way to diagnose the issue is to hire an HVAC technician for a furnace inspection.
Image Credit: articles4smallbusiness.com/furnaces/
