Symptoms
- Constant hum or buzz while the fan runs
- Humming changes with fan speed
- Sound seems to come from the motor housing or a nearby wall control
Likely causes
- CommonA standard dimmer switch being used to control fan speedLight dimmers aren't designed for fan motors and commonly cause humming; fans need a proper fan speed control.
- CommonLoose screws or parts vibrating against the housingVibration-loosened parts can rattle or hum at certain speeds.
- PossibleA worn motor bearingAging motors can develop an audible hum as bearings wear.
- PossibleA failing capacitorCapacitor issues can cause both humming and reduced speed or power.
What to do
- Check what kind of wall control operates the fan; a light dimmer used for fan speed is a common cause and should be swapped for a fan-rated speed control.
- Turn off the fan and tighten visible screws on the housing, blades, and light kit if present.
- Run the fan at each speed to see if humming is worse at a specific setting.
- If humming is present at all speeds and screws are tight, suspect the capacitor or motor bearings.
- Have a fan repair technician or electrician test the capacitor.
- Weigh repair versus replacement if the motor bearings themselves are the cause, since fan motors are often not cost-effective to rebuild.
- Replace a light dimmer being used for fan control with a proper fan speed control switch.
Tools and parts
- Screwdriver
Ceiling fan speed control switchSearch: “ceiling fan speed control wall switch”
When to call a pro
Call an electrician or fan technician if the humming continues after ruling out the wall control and tightening loose parts.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.