Typical vent heater & light fan venting system wiring adapted from Delta Breez Model RAD80L - Contact Delta at  (C) InspectApedia.comBathroom Ventilation Fan Wiring Guide
Bathroom exhaust vent wiring installation

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Bath vent fan electrical wiringinstallation, troubleshooting, repair:

How to wire a bathroom vent fan, how to install bathroom venting. How to make the proper electrical connections to wire a bathroom exhaust vent fan or a fan incorporating also a light and a heater. Bath vent fan wiring diagrams including bath vents with light or heater.

Broan & Nutone ventilation fan wiring instruction manuals.

This article series describes how to install bathroom ventilation systems, fans, ducts, terminations. We include bathroom venting code citations and the text also explains why bathroom vent fans are needed and describes good bath vent fan choices, necessary fan capacity, and good bath vent fan and vent-duct installation details.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Bath Vent Fan Wiring Connections

Simple fan only wiring for a Nutone Model 8814R and similar bath vent fans (C)  adapted from Nutone Typically the bathroom vent fan motor is powered by the bathroom ceiling light fixture circuit; some installers, particularly in hotels or rental units, hard-wire the bath exhaust vent fan to force it on when the bathroom ceiling light is on - thus assuring that the vent fan is in fact used. If the bath vent fan is noisy this forced-on status can annoy everybody.

In the simplest case there will be just three fan wires to connect: black to black (the hot or live or power wire), white to white (the neutral wire), and ground to ground, typically a bare ground in the house wiring to a green ground wire in the fan housing wiring set.

The most general fan wiring instructions will state: "Hook up the bath vent fan wiring by removing the electrical junction box cover. Next connect the house wires to the fan wires: ground to ground, neutral white to neutral white, and hot black to hot black."

Do not just twist or tape wire ends together. Wire connections are made using a twist-on connector ("Wire nut").

[Click to enlarge any image]

If the bath exhaust fan includes a separate light the light may use the same power circuit as the fan but will require its own switching circuit. If the bath vent fan includes a separate electric heater, the heater will usually require its own separate circuit and control switch.

But when the fan includes also a light and perhaps an electric heater there are actually three circuits to complete, each with its own controlling switch.

Shown below, electrical wiring connections for a typical fan, light, & heater combination vent fan system, are adapted from installation instructions for the Delta Breez Model RAD80L installation manual cited below.

Watch out: if a bath vent fan, light, or heater are installed close to a tub or shower or where they can be reached by someone in those facilities GFCI protection is required for all of its electrical circuits. See GFCI PROTECTION, GFCI CODES

Typical vent heater & light fan venting system wiring adapted from Delta Breez Model RAD80L - Contact Delta at  (C)

Watch out: Electrical wiring should be done by a licensed, qualified expert. If the fan is installed close to a tub or shower, such that it could be touched from those locations, it's electrical circuit should be GFCI protected.

Never put electrical controls such as switches where they can be reached from a bathtub or bathroom shower.

Typical wiring instructions for a bathroom vent fan that includes both a light and a heater state the following - note that these adapted excerpts and are NOT complete installation instructions nor may they match your specific fan. Be sure to obtain the proper installation instructions for your fan brand and model:

Wiring details for a fan heater light combination adapted from Delta Breez Model RAD80L installation instrucations (C)

Remove the fan junction box cover a . Using wire nuts (not supplied), connect house wires to fan wires b as shown in the wiring diagram on page 10. Wire connections are as follows: black to live switch wire, white to neutral, green to ground.

Reattach fan junction box cover c .

Check the plug from the fan into the receptacle marked “Vent”

Plug the Light Connector into the receptacle marked “Light”

Manufacturer sources for free bath vent fan installation instruction manuals:

Question: electrical wiring connections for the bath vent fan?

(May 23, 2016) Cherie carmona said:

I am attempting to install our bathroom fan, after removing old one discovered, there are other wire connections that are all together, for other power sources, one for fan, one power source for other room, and another, do I just hook them all back together?


Cherie with apologies because we'd prefer to be helpful, I simply can't risk your life, the lives of others, and the risk of burning down the building by guessing at what wires are present and how they should be connected. I just have so little information that speculating sounds dangerous.

In some jurisdictions homeowners are permitted to do their own wiring but still require an electrical inspection; what does your local building department say? I know it's costly to hire an electrician to do one trivial hookup; perhaps there is other electrical work that can be combined?

Watch out: certainly DO NOT just twist a bunch of wires together: in the best case you'll trip a breaker or blow a fuse; in a worse case somebody could be shocked or killed or you could start a fire.

Typically a hot wire brings power to the fan, there may be other powered wires that are switched that bring current to a light or to a heater or to all three. It's true that neutral wires may be connected in common.

Find the fan's wiring instructions by noting its brand and model and then asking the manufacturer for an installation guide. Usually those are free and can be downloaded from the manufacturer's website. Wiring details may also be on a sticker in the fan appliance itself.

Question: bath vent fans not working even though wired-up

(June 2, 2016) Mark said:

At work, each bathroom has an industrial exhaust fan - 4 in total that don't work. I know this sounds crazy, but they appear wired. The only thing I can access is a small 1.5 inch by 2 inch single screw metal cover.

When removed, I can see a Yellow/Green wire - ground, going from a green screw, to a pigtail containing 2 more wires - common and neutral - I assume - Black and White. Since it's only a single-speed fan, there are only 3 wires total - unlike the blower motors used in HVAC. Oh, I forgot to mention that this exhaust fan is looks like a blower motor out of an HVAC system, but about 1/2 the size.

Anyway, I can see that from one pigtail connection, one end goes to the motor of course, and the other, the green/yellow goes to that green ground screw, but I cannot tell where the black and white go (somewhere up to the top of the assembly. Here's the strange part - there aren't any wires going out of the unit - nor do I see a place for them to exit.

There also isn't your typical 'notch/bump" in that little cover to allow the ground to come out of there either. Is it possible that they installed these things and NEVER hooked them up? Or, it is possible the power feed comes in and exits through the 12" commercial insulation style exhaust pipe that is taped to the top of the unit?

This one has me scratching my head, but since none of them work when you turn the light on (only 1 switch in each bathroom), I assume the expensive units were installed 10+ years ago and never hooked up. There isn't a SPECK of dust in the fan/motor blade/housing.


Sounds like mis-wiring as well as sounding like a need for someone experienced to test for live voltage and trace the circuits and switches involved.


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