Bathroom Fan Fix: How to Repair or Replace Your Exhaust Fan Fast

If your bathroom fan is humming, rattling, or just won’t turn on, you don’t have to live with a steamy mess. Most fan problems are simple enough to handle with a few tools and a bit of patience. In this guide we’ll walk through the safest way to spot the issue, clean out the grime, and swap out a bad motor if needed.

Step 1: Safety First and Quick Checks

Before you lift a fan, turn off the power at the circuit breaker. A quick test with a voltage tester confirms the circuit is dead – you’ll thank yourself later. Next, remove the cover grille. Most grilles just snap or screw off; keep the screws in a safe spot.

With the grille off, give the blades a good visual inspection. Dust, hair, and soap scum build‑up are the main culprits of noisy fans. A soft brush or a vacuum with a brush attachment clears the debris in a minute. If the fan still sounds off after cleaning, the motor may be the problem.

Step 2: Diagnose the Motor or Switch

Spin the blades by hand. They should move freely; any grinding feels like a motor bearing issue. If they stick, lubricate the shaft with a few drops of light oil. For a motor that won’t run at all, check the fan’s pull‑chain switch (if it has one) or the wall switch. A multimeter set to continuity will tell you if the switch is broken – no continuity means replace it.

When the switch checks out, test the motor directly. Disconnect the wiring harness (note which wire is which) and apply 120 V to the motor’s terminals with a plug‑in tester. If the motor spins, the wiring is likely the problem; if it stays dead, the motor has burned out and needs swapping.

Step 3: Replace a Faulty Fan

Buying a replacement is easy – match the size (usually 4‑inch or 6‑inch), voltage, and airflow rating (CFM). Most new fans come with a mounting bracket that fits the old one. Remove the mounting screws, pull the old fan out, and detach the wiring.

Attach the new fan’s wiring to the house wires using wire nuts (black to black, white to white, ground to ground). Secure the fan with the supplied screws, re‑attach the grille, and flip the breaker back on. Test the fan – you should hear a steady, quiet hum and see airflow when you run hot water.

If the fan still misbehaves after these steps, it’s time to call a professional. Re‑wiring errors or hidden duct damage can cause lingering issues that need a qualified electrician or HVAC tech.

Now you know the whole process: turn off power, clean, test the switch and motor, and replace the unit if needed. Most bathroom fans are fixed in under an hour, saving you the cost of a service call and keeping your bathroom dry and fresh.