Installing a ceiling fan is a useful home improvement job that can help keep air circulating in your house and save you money on your heating and cooling bills. Your work isn’t over once the fan itself is in place, however. To complete the job, you still need to install a ceiling fan speed control switch to get the most from your new fixture.
For an experienced handy person, wiring up the control in the wall receptacle is a fairly easy task, but some homeowners find the job to be pretty confusing and intimidating. Read on to learn about how to replace a ceiling fan switch and make sense of that tangle of wires inside the box.
Ensure You’re Using a Fan Control Switch, not a Light Dimmer
Before you start your installation, make sure you have the right switch for the job. Generally, fan speed control switches should be labeled as such somewhere on the plate. If instead your equipment says something about incandescent fixtures only, it is intended to be a light dimmer and will not work with your fan. Fan controls and light dimmers do two different jobs. Light dimmer switches work by raising the electrical resistance which in turn reduces the voltage and so dims the light, but if hooked into a fan could cause it to hum loudly, or the dimmer might heat up and even catch on fire.
How to Choose the Right Speed Control Switch
To choose the correct fan control switch, check the amperage on your ceiling fan. Most ceiling fans use less than 1 amp so it’s best to use a control dimmer that’s a little higher, like 1 to 1.5 amps. If you’re setting up multiple ceiling fans to one controller, you’ll need to add their amps together and get a control that matches their total. Be sure to set the fan to the highest speed, which is generally done using the pull chain, to avoid problems with the new control switch.
How to Replace a Ceiling Fan Switch
If you’re replacing an old switch, all you’ll need to do is to swap out the existing equipment and connect the new fan control switch. New fan switches come with two black leads (load) and one green (ground). Usually, it doesn’t matter which black lead you connect to the black conductor wire going to the fan load or line. The switch will work either way.
Follow these steps to complete the job:
- Turn off the circuit breaker for that circuit at your breaker panel.
- Remove the faceplate and pull the switch from the wiring box. Disconnect the black conductor wires and bare wires from the old switch and remove.
- Typically, two romex cables enter the wiring box. The sheathing is stripped off the cable so there can be 6 wires inside the box. Two are black conductors, two are white neutral wires, and two are bare ground wires.
- The white neutral wires are probably connected with connecting caps. Leave these alone.
- Using a wiring connector cap, connect one of the black conductor wires in the wiring box to one of the black wires on the new switch. Do the same with the other black conductor to the other black wire from the new switch. Be sure that there’s no bare wire exposed from either of these conductors as it could easily cause a dangerous short. Do not over tighten, which could cause a wire to poke through the end of the wiring cap.
- Connect the bare wire to the green grounding wire from the new switch.
- Carefully fold and push all the wires back into the wiring box.
- Mount and align the control switch onto the box. Install the screws to hold it in position.
- Reattach the faceplate.
- Turn on the circuit breakers.
- Test the fan and enjoy your newfound control over the breeze.
What to Do if There Are Only Three Wires Inside the Box
Once you start unscrewing faceplates, you may find yourself encountering conditions that vary from the scenario described above. Even if your box looks a little different, with a bit of flexibility and research you should still be able to figure out how to install your ceiling fan switch. One common setup you might find is a box with only three wires. When the power supply connection, or line, is made in the ceiling wiring box, electricians will run a single romex cable down through the wall to bring power to the switch. Known as a switch at the end of cable run, line power connects to the white wire and leads (through the romex) to the switch. The black load wire takes the electricity back to the fan. Uniform wiring code requires black electrical tape on the white wire to indicate that white wire is a conductor and not being used as neutral. For connections, treat this white wire with the black tape on it as a black conductor wire and connect it to one the switch’s black wires.