If you want to find the common causes of ceiling fans humming, you are on the right website!
In this guide, you will learn:
- The 9 causes of ceiling fan humming noises
- Why dimmer switches are a frequent source of vibrations on hums
- And more...
As a licensed home inspector, I have tested thousands of ceiling fans in my career. And sometimes they make a lot of noise and vibrations!
I don't usually try to diagnose the cause of strange humming sounds from ceiling fans during a home inspection — it just isn't my job. But my clients will still ask, "Why is my ceiling fan humming?".
I would say 70% of the time the humming sounds come from the light covers or light bulbs. A loose light cover or faulty bulb can create a racket with a hum that goes through the entire unit.
Keep reading to learn the 9 typical causes of ceiling fan humming noises!
9 Causes Why Ceiling Fan Makes Humming Noise
Humming ceiling fans can have several causes, and sometimes it is as minor as tightening a few bolts or even changing the light bulbs. Other times the humming may be coming from a dimmer switch or unbalanced fan blades.
Below are the 9 typical causes of ceiling fan humming...
- Ceiling Fan Uses A Dimmer Switch
- Loose Or Faulty Wire Connectors
- Loose Light Covers
- Loose Ceiling Fan Housing Screws
- Vibrating Light Bulbs
- Older Ceiling Fan Needs Lubricating Oil
- Unbalanced Fan Blades
- Ceiling Fan Is Past Life Expectancy
- Small Piece of Metal Or Plastic Inside of Housing
Cause #1 - Ceiling Fan Uses A Dimmer Switch
A ceiling fan making humming noises may be improperly connected to a dimmer switch.
Ceiling fans are NOT meant to be connected to the average dimmer switch, and the dimmer will 'throttle' or reduce power to the ceiling fan. This reduced electrical energy will strain and weaken the ceiling fan causing it to hum loudly.
And even if the rheostat (dimmer switch) is designed for use with ceiling fans, they can still cause humming noises, according to EnergyStar.gov.
Simply hire an electrician (or do it yourself if handy) and change the dimmer switch to a single pole switch.
Read Also >> How Much Weight Can A Ceiling Fan Hold?
Cause #2 - Loose Or Faulty Wire Connectors
Ceiling fans are connected to the home's electrical system through a 'fan rated' electrical box in the ceiling.
If the wire nuts are loose or improperly connected, it can cause vibrations and transfer to the rest of the ceiling fan. Likewise, if the wiring is loose inside the ceiling fan rod, it may also be causing a high hertz vibratory energy through the ceiling fan.
The solution is to check all wiring connections to make sure they are tight, and to remove any wiring slack in the ceiling fan rod.
Cause #3 - Loose Light Covers
If your fan has lights, the light covers may be causing the ceiling fan humming noises.
The easiest way to know is to turn on the ceiling fan, and to grab or push on the light covers to see if the humming stops.
Homeowners will need to tighten the screw(s) or bolt that is holding the light covers in place to get rid of the humming.
Read Also >> How To Fix A Broken Ceiling Fan Pull Chain?
Cause #4 - Loose Ceiling Fan Housing Screws
Similar to the light covers, there may be a loose screw in the housing or other parts of the ceiling fan that is causing the humming.
Use a screwdriver to tighten all the screws in the ceiling fan that are visible.
Don't use 'gorilla' force to tighten them, just a moderate amount of force. Try not to strip the screw threads.
Cause #5 - Vibrating Light Bulbs
All light bulbs vibrate to a small degree. However, you may have some faulty light bulbs that are vibrating excessively.
The easiest solution is to just change the light bulb and see if the humming noise of the ceiling fan goes away.
Homeowners can also turn on the fan and press gently on the light bulbs to see if the humming goes away. If the humming stops, then you know the light bulb is the culprit.
Just make sure the bulb is still cool to the touch or use gloves!
Cause #6 - Older Ceiling Fan Needs Lubricating Oil
Older ceiling fans need periodic oiling of their motors.
All modern ceiling fans have 'permanently sealed' motors and don't need extra oil. If you have an old ceiling fan, you need to find out if there is an 'oil port' which is a small hold where you can add oil.
Adding lubricating oil may greatly reduce any ceiling fan humming noise that is coming from the motor.
Looking up the manual oiling instructions of that brand and model of ceiling fan is recommended.
Cause #7 - Unbalanced Fan Blades
It may seem unlikely, but misaligned fan blades can create a humming fan or vibration in the rest of the ceiling fan.
If you want to quickly know if this is the case, homeowners can temporarily remove the fan blades from the ceiling fan. If the fan humming noise goes away when you turn on the ceiling fan, then you know the unbalanced fan blades are the problem.
Homeowners can hire a handyman or contractor to fix the unbalanced blades or do it themselves with DIY balancing kits. These balancing kits come with weights that you fasten to the top of the fan blades.
Cause #8 - Ceiling Fan Is Past Life Expectancy
Let's face it, you may just have a really old fan that needs to be replaced. The average life expectancy of ceiling fans is about 10-years.
Your current ceiling fan may have an older AC motor that is far past its life expectancy. Modern ceiling fans typically come with DC motors that are significantly quieter than the older AC motors.
With an old ceiling fan, the winding copper coil may be degraded (unglued) or the magnets on the coil could be loose. Likewise brushes on the motor may need to be replaced.
Energy.gov recommends always checking the noise ratings (measured in sones) for the ceiling fan and to listen to the fan PRIOR to purchasing it.
Read Also >> What Are The Best Low Profile Ceiling Fans?
Cause #9 - Small Piece of Metal Or Plastic Inside of Housing
There may be some small debris inside of the ceiling fan housing that is causing the vibrations.
Homeowners will need to remove the housing cover and possibly remove the ceiling fan from the ceiling rod. Carefully look over the inside of the ceiling fan for any debris.
Final Thoughts On Ceiling Fans Making Humming Noises
Nothing is more frustrating than a ceiling fan humming that can be heard across the house!
The most common culprits are a loose light cover or light bulb. And sometimes homeowners have the ceiling fan connected to a dimmer switch which is a big mistake.
Dimmer switches will throttle power to the ceiling fan putting excessive strain on the motor — leading to loud fan hums.
But there are a variety of causes as to why a ceiling fan is humming. I hope you enjoyed this guide from Home Inspector Secrets!