A bathroom without proper ventilation is a mold magnet. If your exhaust fan is loud, weak, or just plain dead, replacing it yourself is one of the more manageable electrical/home-improvement hybrid jobs a DIYer can tackle. Here’s how to do it safely.
What You’ll Need
- Replacement exhaust fan (match CFM rating to your bathroom square footage)
- Screwdrivers (flathead and Phillips)
- Non-contact voltage tester
- Wire nuts
- Utility knife
- Ladder
Step 1: Buy the Right Fan
Measure your bathroom. As a rule of thumb, you need at least 1 CFM of ventilation per square foot. So a 60 sq ft bathroom needs a fan rated at 60 CFM or higher. Look for an Energy Star rating and a sone level under 1.5 if quiet operation matters to you.
Step 2: Turn Off the Power
Flip the breaker for the bathroom at your electrical panel. Then use a non-contact voltage tester at the fan’s wiring to confirm power is off before you touch anything. Never skip this step.
Step 3: Remove the Old Fan
Take off the grille cover (usually clips or screws). Unplug the motor if it has a plug connector. Remove the mounting screws holding the housing to the ceiling joist or mounting bracket. Carefully pull the housing down and disconnect the wires, noting which wire goes where (take a photo).
Step 4: Install the New Fan
If the new fan’s housing fits the existing hole, installation is straightforward: connect the wires (black to black, white to white, ground to ground), secure the housing, attach the duct connector, and screw the cover back on. If the hole needs enlarging or the duct routing changes, that adds time but is still DIY-able with patience.
Step 5: Test It
Restore power and flip the switch. The fan should run quietly and you should feel suction at the grille. Hold a piece of toilet paper up to it — it should hold against the grille from the airflow.
When to Call a Pro
If there’s no existing vent duct (common in older homes), or if you need to run new wiring, hire an electrician and possibly a contractor to handle the ductwork properly.