How To Replace And Install A Bathroom Exhaust Fan To A Quiet Motion Sensor Exhaust Fan! DIY Tutorial, by Fix This House on YouTube. 9 min 52 s.
- Video length
- 9 min 52 s
- Time to do it
- 2 hours
- Difficulty
- Medium
- Steps
- 9
What you need
Steps
Turn off the bathroom fan circuit at the breaker panel. Use a voltage tester at the switch to confirm the power is off before you touch anything.
Remove the old fan grille by pulling it down or unscrewing the clips. Then unscrew the fan housing from the ceiling joists.
Disconnect the duct from the old fan and loosen the wire nuts on the house wiring. Note which wire is hot, neutral and ground.
Trace the new fan's housing opening on the ceiling and cut it out with a keyhole saw. Check the joists so the housing screws into solid wood.
Feed the house wiring through the new housing knockout and clamp it. Connect hot, neutral and ground with WAGO or NM connectors.
Attach the 4 inch insulated duct to the new fan outlet with a hose clamp. Seal the joint with vent tape so air does not leak.
Push the housing into the ceiling opening and screw it to the joists. Make sure it sits flush and does not wobble.
Set the motion sensor and humidity settings on the fan, then snap the grille into place.
Restore power at the breaker and test the fan. Check that it starts on motion and runs quietly with good airflow.
Tips and common mistakes
Never work on the fan until the breaker is off and tested, since bathroom fans share circuits with lights.
Match the new fan's CFM and duct size to your old setup, or airflow and noise will suffer.
Seal every duct joint with vent tape and support the duct with wire ties so it does not sag.
If your ceiling has no joist near the opening, add a short wood brace before screwing in the housing.
Questions
Do I need an electrician to replace a bathroom fan?
If you are comfortable connecting three wires with the power off, most homeowners can do it. Call an electrician if the wiring is old, damaged or you are unsure which wire is hot.
What size fan do I need for my bathroom?
A common rule is 1 CFM per square foot of bathroom floor space. A 100 square foot bathroom needs about 100 CFM, so an 80/110 CFM model covers most small to medium rooms.
Why is my new fan still noisy?
Loose mounting, an undersized duct or a kinked flex duct are the usual causes. Check the housing screws and make sure the duct runs short and straight.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
