Symptoms
- Fan runs but light or heater section doesn't work, or vice versa
- Only one function responds to its switch
- Unit worked fully before one section stopped
Likely causes
- CommonA burned-out bulb in the light sectionThe light portion fails independently of the fan motor.
- CommonA tripped thermal cutoff on the heater sectionHeater elements in combo units often have their own safety cutoff separate from the fan.
- PossibleA failed switch for one specific functionMulti-function units often use separate switches or a multi-gang switch plate that can fail individually.
- PossibleA failed motor or heating element for just that sectionEach function has its own component that can fail on its own timeline.
What to do
- Test each function (fan, light, heater) individually using its specific switch.
- Replace the bulb if the light section is the one not working.
- Let a heater section cool and check for a reset button on the unit if it stopped after running.
- Check the breaker panel for a trip if more than one function stopped at once.
- Turn off the breaker and check switch wiring if a specific switch seems to be the point of failure.
- Have an electrician test the specific failed component, since combo units can have several independent parts.
- Consider replacing the whole unit if it's old and multiple sections are failing.
Tools and parts
- Step ladder
Replacement bulb or heater element for combo unitSearch: “bathroom heater fan light combo replacement parts”
When to call a pro
Call an electrician if a specific function's wiring or motor needs replacing, or the whole unit needs swapping.
Safety
Use caution
Let a heater section cool before touching it, and turn off the breaker before opening the unit.