How to Wire a Bathroom Exhaust Fan with Light and Heater

Last Updated on May 11, 2022 by Vernon Scott

Working with electricity is a thing we should do with patient and cautiousness. Most of the time, we should only hire a certified electrician to do the job. But in case you are changing an existing exhaust fan, you can do it by following some simple steps.

Bathroom exhaust fans are wired with light and often a heater. You should examine the wiring carefully before you take out the previous fan. In this article, we will show how to wire a new exhaust fan in your bathroom with light and heater.

Prepare the Necessary Instruments

You must have everything ready near you when working with electricity. For this project, gather these tools-

  • The tools that come with the exhaust fan.
  • Wire nuts. Usually, they come with the exhaust fan.
  • Electricity Tape.
  • A step ladder.
  • The new exhaust fan.
  • Additional light source. For example, a torchlight.

After collecting them, follow the procedure below.

Replacing the Old Exhaust Fan with a New One

As you are ready, try to go through each of these steps-

  • Turn off the electricity using the circuit breaker. As it gets darker, use the additional light source.
  • Have a look at how your old exhaust fan is wired. They can be arranged in multiple ways, depending on your bathroom switches. Your job is to find out which wire is for which electrical unit. Here are three methods you can find the wiring in-
  • If your bathroom has separate switches for the fan, light, and heater, you will find multiple wires connected to the exhaust fan.
  • There can be a single switch for both light and fan and a different one for the heater.
  • There can be one switch for all of them. In this case, you should actually contact an electrician to do the wiring.
  • Disconnect the old wires from the exhaust fan and keep labeling them least you forget which wire is which. They may be color-coded too.

Connecting the New Wires

Once you have disconnected the wires and old fan and installing the new one, now it’s time for reconnecting them. In this case, you may mostly need to connect the same colored wires, which means black to black and white to white. But it can be different based on how your home wiring is.

The best thing to do is to follow the labels you have given earlier on the wires and connect them correctly.

Don’t end up connecting the heater wire to the wrong switch, and the same for the light and fan. Connect one wire and move on to another. The wiring should be as follows-

  • You may need to connect multiple white wires from the exhaust fan to a single white wire from the switch.
  • Mostly there will be some black to black wire connections. These black wires will transfer the electricity to the fan, light, and heater. You should connect the correct black wire to the correct switch. You may use the labeling to help you.
  • For the color-coded wires of the exhaust fan, you may need to follow the instruction manual.

Test the Exhaust Fan

While testing whether your wiring is right, there can be several situations-

  • As you turn the circuit breaker on, it can immediately tip and open. In that case, there is a problem with your wiring. You should keep it open and recheck the wiring.
  • If it doesn’t tip open, then test each switch separately first. Then test all the functions at the same time. If all works well, everything is wired correctly.
  • When you turn on all the functions, the circuit breaker can tip. In that case, the wiring is small and can’t take the load. Bring an authorized electrician in this situation.

Frequently Asked Questions

How Do I Wire My Bathroom Exhaust Fan, Light, and Heater That Has Only One Switch?

In that case, you should add additional wiring. Hire a professional to do this job.

What Tool Should I Use to Connect Two Wires?

Use wire nuts to connect two wires. Do not only use electricity tapes.

Should I Replace My Old Wire Nuts?

Indeed, you need to replace your old wire nuts while reconnecting your wires.


Make sure to stay careful for the entirety. It is inside a bathroom, where there can be water around. Let no wire touch any wet place. Your hands should be totally dry even though you have shut the circuit breaker off.

If you have no experience with any electrical wires before, this project should be left in charge of a professional. Don’t connect any wire just because you feel like it is the correct wire. Follow the labeling and instructions well.

I am a Trained HVAC Technician and Author of EmiNick. I have been in the industry for over 10 years and have gained a wealth of knowledge and experience. I have been involved in all aspects of HVAC, from design and installation to repair and maintenance. I am also a certified energy auditor and have experience in conducting energy audits for both residential and commercial customers. In addition to my HVAC experience, I am also a certified home inspector and have conducted many home inspections for both buyers and sellers. Follow Me: Linkedin

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