What we do on bath fans
- Fans replaced like for like in the existing housing and wiring
- Motor kits fitted where the original housing is still sound
- New grilles and covers for yellowed or broken ones
- Blowers and grilles cleaned of dust and lint
- Duct connections and dampers checked and resealed
- Roof and wall caps checked so the flap opens
Bath fans in period bathrooms
Many San Gabriel houses date from the 1920s–1950s, according to the City’s historic resources survey, and their bathrooms were designed around an operable window. Fans were added later, often through a ceiling with little attic room and a duct that was never well supported. We check that path when we swap a fan.
The U.S. Department of Energy’s Energy Saver guide recommends turning bath exhaust fans off within 20 minutes after bathing, unless they are designed for continuous operation, and suggests that when replacing them you “consider installing high-efficiency, low-noise models.”
How we swap a fan
Power off and inspect
We shut off the circuit, remove the grille and look at the housing size, the motor connection and the duct collar.
Match the replacement
We fit a motor kit or a fan that matches the housing and existing wiring, with quieter options when they fit.
Check the air path
We check the duct for kinks, gaps and sag, and that the cap flap opens, then test airflow at the grille.
What goes to an electrician
We replace existing fans on existing wiring. Adding a fan where there was none, new wiring or circuits, moving the switch, or adding a heater or light that needs more wiring goes to an electrician.
Photos that help
A photo of the grille, the inside of the housing with the grille off if you can, any label, and what is wrong.
Bath fan questions
Is a fan with a light included?
Only as a like-for-like swap where the existing fan already has a light on the existing wiring. Adding a light where there was none goes to an electrician.
Can the old fan stay and just get a new motor?
Often, yes, when the housing is sound and the maker sells a matching motor and blower kit. That avoids opening the ceiling.
How long should I run the fan?
Long enough to clear the steam. The DOE guide suggests turning it off within 20 minutes after a shower, unless it is a fan designed to run continuously.
Do you replace the grille only?
Yes. A yellowed or cracked grille can be replaced with one made for that fan, or a universal cover that fits the opening.
How can I tell if the fan works?
Hold a square of toilet paper to the grille with the fan running. If it is not pulled flat, the fan is weak or the duct is blocked.
Why is my fan so loud?
Worn bearings, a loose blower wheel or a dust-heavy fan. A replacement motor or a newer low-noise fan usually fixes it.
Can you add a fan where there is none?
No. That needs new wiring and a new duct, which goes to an electrician.
Will a new fan fit my old opening?
Many do, and some brands make replacement kits for older housings. We measure before ordering.
Does the fan need to vent outside?
Yes. A fan that blows into the attic moves moisture into the attic. We check where the duct ends.
Related guides for San Gabriel homes
- Resealing the tub and tile in an older bathroomHow we remove old caulk and reseal tubs, vintage tile and pedestal sinks in older San Gabriel bathrooms to keep water out of the walls.
- A move-in checklist for an older houseWhat to check and fix when you move into an older San Gabriel home, from shutoffs and smoke alarms to locks, outlets and window hardware.
We’re a handyman in San Gabriel for small repairs like this one, with an upfront price by text.
This job sits in our electrical fixture swaps group. For other repairs, see the services overview, or start with the repair guide for San Gabriel’s older homes.