Most bathroom vent fan and heater failures trace to power, a bad wall switch, or a clogged blower, and the fix order starts at the breaker.
Power loss, a dead wall switch, and loose wiring explain most cases of a bathroom vent fan and heater that stopped working, and none of them call for a new unit. Broan-NuTone’s published bath fan guidance runs the same ladder: check the breaker panel, test or replace the wall switch, cut the power and inspect the wiring connections, then replace the motor only if power is confirmed at the fixture.
Work top to bottom and most breakdowns land on one of the first two rungs. The table below maps each symptom to the check that settles it fastest.
Bathroom Vent Fan And Heater Stopped Working: Where To Check First
Start at the breaker panel, not the fixture. A tripped breaker or a wall switch that no longer closes the circuit accounts for most total failures, and both take under a minute to rule out.
- Shut off the breaker that feeds the bathroom before the grille or housing comes off.
- Reset the breaker and listen for the fan. If it trips again right away, leave it off and call an electrician.
- Flip the wall switch on and off. If nothing responds, test the switch with a multimeter or swap in a new one.
- With the power off again, open the housing and look for loose or corroded wiring connections.
If the unit powers up and the breaker holds, the power side is clear and the fault sits somewhere else. A wall switch is the cheapest part in the chain and the one most likely to wear out, so test it before you suspect the motor. Wiring inside the housing loosens over years of heat cycles, and a loose connection can leave the whole unit dead without tripping anything.
Broan-NuTone publishes the same order in its bath fan troubleshooting guides, with one addition worth knowing: combination fan, heater, and light units often run on separate circuits, so a dead light or a cold heater may have nothing to do with the fan motor.
| What You See | Likely Cause | Check That Settles It |
|---|---|---|
| Unit is completely dead | Tripped breaker or lost power at the circuit | Reset the breaker at the panel and retest |
| Dead with a live breaker | Failed wall switch or loose wiring | Test the switch, then inspect connections inside the housing |
| Fan runs, heater stays cold | Heater breaker, heater element, or the switch setting | Check the heater circuit and confirm heat is selected on the switch |
| Weak airflow | Dust-choked grille or blower wheel | Remove the grille and clean the blades and wheel |
| Grinding or rattling noise | Debris in the blower or a blocked duct | Clean the wheel, then check the duct run and exterior vent |
| Light is out, fan is fine | Independent light circuit or a spent lamp | Treat the light as its own fault and trace that circuit |
| Burning smell, arcing, melted parts, water near wiring | Unsafe electrical fault | Cut power at the breaker and call a qualified electrician |
Why Does The Fan Run But The Heater Stay Cold?
A fan that spins while the heat stays off points to the heater’s own circuit, element, or control switch, not the motor. Broan-NuTone lists “fan operates, but heater does not” as a common failure mode in its fan-heater documentation.
- Heater circuit breaker: the heater side of a combo unit often sits on its own breaker, so scan the panel for a second tripped switch.
- Wall switch setting: on the Broan-NuTone 665RP heater, fan, and light combo, heat comes on only when the heater function is selected at the switch.
- Heater element: if the breaker is set and the switch is on, the element is the remaining suspect.
Broan-NuTone also keeps a technical service video for the BHFLED80 fan-heater assembly, which helps if you want to see the wiring layout before you open the housing. When those three checks come up empty, the company’s own guidance is customer support or a qualified electrician rather than more disassembly at home.
If the element is the failed part, a replacement unit usually costs less than the repair visit. Our tested bathroom vent fan and heater roundup compares the current combos side by side.
Clogged Blowers, Noisy Fans, And When To Stop
Weak airflow and growling noise point to buildup or a blocked duct, not a dying motor. Dust on the blower wheel cuts airflow, makes the unit louder, and lets the motor run hotter than it should.
- Pull the grille and vacuum the fan blades and blower wheels.
- Trace the duct run for kinks and confirm the exterior vent flap opens freely.
- Check the light separately, since Broan-NuTone documents light failures as their own fault.
Stop and call a qualified electrician if you smell burning, see arcing or melted parts, trip the breaker more than once, or find water anywhere near the electrical parts. A bathroom exhaust fan generally does not need GFCI protection unless it sits directly over a shower or tub, or the manufacturer’s instructions call for it.
If the room still steams up, run the checks in order: reset the breaker and retest, test or replace the wall switch, open the housing with the power off to inspect the wiring, clear the grille and blower wheels, and check the heater circuit last.
FAQs
Can a bathroom exhaust fan run without GFCI protection?
Usually yes. Standard hardwired bathroom exhaust fans are not required to sit on a GFCI circuit unless the unit is installed directly over a shower or tub, or the manufacturer calls for it. If you cannot tell which circuit feeds the fan, an electrician can confirm it during a routine panel check.
What does it mean when the fan only hums?
A hum with no spinning means the motor has power but cannot turn, which usually points to a jammed wheel or a worn bearing. Cut the power at the breaker, remove the grille, and clear anything blocking the blades. If the wheel turns freely by hand and it still hums, the motor is the likely failure.
Should I repair or replace the whole unit?
Repair wins when the trouble is a switch, a breaker, or simple buildup, since those are cheap and quick. Replace when the motor or heater element has failed on an older unit where parts are hard to source. Broan-NuTone’s guidance says to contact support or an electrician when basic checks do not resolve the problem, which is a fair point to price a new unit.
References & Sources
- Broan-NuTone. “Bath Fans.” Troubleshooting steps covering the breaker panel, wall switch, wiring connections, and motor replacement.
- Broan-NuTone. “Light Is Not Working.” Shows that fan, heater, and light faults can sit on separate circuits.
- Broan-NuTone. “Technical Service Videos.” Includes the BHFLED80 fan-heater assembly troubleshooting video.