Set Up a Timer for Your Whole House Fan

By We re still here！ | Published: 2026-10-18

Category: How-to Guides

Learn how to install and use a 12-hour timer for your whole house fan or bathroom fan. Step-by-step guide with common mistakes to avoid.

Quick Answer

Install a manually set, wind-up 12-hour timer in your wall to control your whole house fan or bathroom fan. This setup gives you simple, reliable on/off scheduling without needing smart home wiring.

Why a Mechanical Timer Works Best for Whole House Fans

Whole house fans pull large volumes of air and often run for hours at a time. A digital timer can be overkill or require extra wiring. A mechanical 12-hour timer is straightforward: you turn the dial to set how long the fan runs, and it shuts off automatically. No programming, no batteries, no Wi-Fi needed.

The same timer works well for bathroom fans that need to run after a shower to clear humidity. Just set it and walk away.

What to Look for in a Fan Timer

Make sure the timer is rated for the fan's amperage. Most whole house fans draw 3-8 amps, and a standard in-wall timer handles that easily. The 12 Hour Timer for Whole House Fans and Bathroom Fans is manually set and wind-up, so it keeps working even during a power outage. It installs in a standard wall box and has a 1-12 hour control setting with an off function.

One trade-off: you cannot set multiple on/off cycles in a day. If you want the fan to run at specific times (e.g., 7-9 AM and 6-8 PM), you would need a programmable digital timer instead.

Step-by-Step Timer Installation

Turn Off Power at the Breaker: Locate the circuit that powers your fan and switch off the breaker. Use a voltage tester to confirm no power is present at the existing switch box. Skipping this step risks electric shock. Always double-check with a tester.
Remove the Old Switch: Unscrew the wall plate, then remove the screws holding the existing switch. Pull the switch out gently to expose the wires. Note which wire is line (hot) and which is load (to the fan). Take a photo of the wiring before disconnecting anything. It helps if you get confused later.
Connect the Timer Wires: Connect the timer's black wire to the line (hot) wire from the breaker. Connect the timer's red wire to the load wire going to the fan. Connect all ground wires (bare or green) together with a wire nut. Tuck the wires neatly into the box. If your timer has a white neutral wire, cap it off with a wire nut—do not connect it to anything unless your fan requires a neutral.
Mount the Timer and Restore Power: Screw the timer into the wall box, attach the wall plate, and turn the breaker back on. Test by turning the timer dial to a short setting (e.g., 15 minutes) and listening for the fan to start. If the fan does not run, turn off power and double-check your wire connections. The timer should click when you turn the dial past the current time.
Set the Desired Run Time: Turn the dial clockwise to the number of hours you want the fan to run. The timer will count down and shut off the fan automatically when it reaches zero. To stop the fan early, turn the dial to the off position. Do not force the dial backward—it can damage the mechanism. Always turn clockwise to set time.

Product Facts

12 Hour Timer for Whole House Fans and Bathroom Fans: This manually set, wind-up timer installs in your wall and has a 1-12 hour control setting with off function. For use with whole house fans and bathroom fans. You can set the timer once and let the fan run for up to 12 hours, then it shuts off automatically—no need to remember to turn it off.
12 Hour Timer for Whole House Fans and Bathroom Fans