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Electrical Wiring for a Bath Exhaust Fan

By Dave Rongey - Summary:

How to Install Bathroom Exhaust Fan Electrical Wiring – Fully Explained Photos and Wiring Diagrams for Bathroom Electrical Wiring with Code Requirements for most new or remodel projects.

Electrical Wiring for a Bath Exhaust Fan

I am installing a Hunter model number 83003 exhaust fan, light, night-light combo.

There is no original wiring as I am turning a bedroom into a bathroom and gutted the entire room.

The fixture has one two pin connector consisting of one black wire and one white wire for the fan.

It has one 3 pin connector consisting of one white wire, one black wire for the light, one red wire (night-light).

I ran 12-2nmb from the light switch box to the fixture and connected the black wire from the two pin connector(fan) with the black wire from the 12-2. I connected the white wires from the two pin connector, three pin connector, and the 12-2 together. I connected the bare copper from the 12-2 to the green wire screwed to the fixture box.

That leaves the black wire (light) and red wire (night -light) still to be wired. I removed a black and a white wire from the yellow sheathing of some 12-2 NMB and stored away the bare copper wire. I then ran the black wire from the switch box to the black wire in the fixture (light) and connected them together. I took the white wire and ran it from the switch box to the red wire in the fixture (night-light). I got a red permanent marker and colored the white wire red at the switch box.

All the wire was ran through a gray PVC conduit.

I bought a double switch and a single switch for the light switches so that the fan can run off the single switch and the two lights will run off the double switch.

I have 5 wires sticking out of the metal switch box.

I have to come in from a power source somewhere. I would prefer another circuit for the bathroom but not sure if I have enough wire for it. I may have to temporarily drop down from the attic tying into some old Knob and Tube.

For some reason or other I am a bit confused about hooking up the switches. I have never hooked up a double switch and I wanna make sure I get this right. There are two black screws on one side of the switch, two copper on the other with a green screw in between the two copper. The other switch just has the two copper on one side with the green.

I assume the black wire from the light would hook to one black screw on the double switch while the white wire painted red (night-light) would hook to the other black screw on the double switch. I assume I would need to run the power source to the single switch then run a black wire from it to the double switch. Beyond these assumptions I am clueless and these assumptions may be clueless as well. Why this double switch is throwing me is driving me crazy.

Any help finishing this would be greatly appreciated.

Before anyone asks why I used 12-2.

I am going to eventually wire my whole house with it. It is all I have on hand. I can’t afford to go out and buy anything else right now and I want this bathroom light/fan/night-light working asap.

Thanks in advance for any help.
Background: Rick, a Homeowner from Pocahontas, AR

Additional Comments: Very nice website, if it helps me out with my projects I will gladly donate when I have the extra funds. Right now its really tough.

Dave’s Reply:
Thanks for your electrical question Rick.

I have provided the following links that lead to fully detailed information on this website that will assist you with your electrical question:
How to Install Bathroom Exhaust Fan Electrical Wiring

Bathroom Electrical Wiring

Fully Explained Photos and Wiring Diagrams for Bathroom Electrical Wiring with Code Requirements for most new or remodel projects.

Electrical Wiring

Lighting For The Home
Lighting Electrical Codes

Light Switch Wiring
Wiring Diagrams

Electrical Wire for the Home

For more information about Bath Exhaust Fan
Bath Exhaust Fan

This link is helpful as a Homeowner
Do-It-Yourself Electrical

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4 Responses to “Electrical Wiring for a Bath Exhaust Fan”
  1. Dave Rongey says:

    Hi Tanya,
    To be precise, you will need to provide the Brand and Model or Part Number of the switch you are wiring. A photo would also be helpful, which could be sent using the Question Form instead of the comment form.
    Please Note: It is possible that you have a double switch that does not allow two separate circuits, and is only limited to one power source, therefore you may need to locate a different switch.

  2. Tanya says:

    OK, may be I did not explain it properly. For the second power source (the top), I have one HOT screw and two black wires. (As, I call it, power in, power out) and one neutral screw.

    Do I put one black wire in the screw and one in the back stab location? The MAIN question is…where or how do I attach the second black wire?

  3. Dave Rongey says:

    Wiring a Double Switch for a Bathroom Combo Fan
    Hi Tanya, Great Question.
    The side of the switch with the tab in place allows one circuit to supply power for both switches.
    When you removed the tab you should be left with two screws on each side of the switch, four screws total.
    The top and bottom switches may now be wired for two power circuits, the top switch for one circuit, the bottom switch for the second circuit. The circuit wires attach to the side of the switch where the tab has been removed.
    Side Note: Be sure to keep track of your neutrals and keep them separate for each circuit and the appropriate device, unless the two circuits are part of a multi-wire circuit where the neutral wire is shared. (I explain this in my book).
    I hope this helps you,

  4. Tanya says:

    Wiring a Bathroom Fan Light Heater Combo
    I guess what I am doing must be unique, because I can’t find information anywhere.

    So here goes, I have a small bathroom, I need 4 switches. In order to save space, I opted for 2 double switches. So, I have a two gang box with 4 switches.

    I have a bath fan/light/heater combo and a vanity light. The plan is to have one switch for each with a separate breaker for the combo unit. The other breaker will have the bath outlets and the vanity light.

    The hardest part is done. The combo works perfectly. Switch 1 (top & bottom) has the heater and the fan. Switch 2 bottom has the light. The one that should be easy is the one I am having problem with. This is a duplex light switch that I want to split, the vanity light will be on the top (from a different breaker) I have broken off the tab. On a typical switch you use both black wires, one on each screw, tie the whites together, tie the grounds together and ground it. By splitting it, I only have one screw for the hot…..WHERE DO I PUT THE OTHER HOT???