I'm going to add a fan to my currently unvented bathroom. The fan installation instructions include the text "if this unit is to be installed over a tub or shower, it must be marked as appropriate for the application and be conencted to a GFCI-protected branch circuit."

The fan is marked as such, but my question is: what is technically "over" the bath? The fan is not directly above the bath. If I were to draw an imaginary line from the top of the shower curtain rod to the ceiling, the fan would be about 4" outside of this line. Does that mean I do not have to put the fan on a GFCI circuit?


5 Answers 5


Let's get one thing straight. Ground-Fault Circuit Interrupter protection for personnel is designed and intended to protect a human (or any animal I guess), from being electrocuted (killed) due to an electrical fault. In most situations, the grounding system will handle any direct faults to ground. A GFCI devices is there to protect you, if you happen to come into contact with an energized conductor.

Let's also be clear that a GFCI device may not protect you from a shock, but should protect you from death (electrocution).


  • You grab hold of the ungrounded "hot" conductor.

    In this situation, the GFCI device should disconnect the circuit before you are killed.

  • The frame of a device is energized, and for some reason the grounding system has not performed its job, and you come into contact with the energized frame of the device.

    In this situation, the GFCI device should disconnect the circuit before you are killed.

A GFCI device is there to protect you, from death.

But why does it seem like codes tend to require GFCI protection in locations where there is water, like bathrooms and kitchens?

The simple answer is that when your skin is wet, it's a better conductor. Because of this, you could potentially provide a fairly good path to ground. It's also important to provide this protection in bathrooms and kitchens, because it's common for plumbing in homes to be grounded.

Let's say you're washing your face in the sink. The water is running, as you reach for a towel. You reach with one hand to turn the water off, while the other fumbles for the towel. While you're still holding the faucet with one hand, the other hand accidentally finds the non-GFCI protected receptacle. The electricity races through your wet hand, across your body, and out your other hand into the well grounded faucet. While crossing your body, the electricity ran right through your heart causing it to stop. Now, you're dead.

If it was a GFCI protected receptacle, you would have gotten a bit of a shock and a scare. But you'd still be alive.

As for the question asked...

Put an imaginary box around the tub/shower, and extend it all the way up to the ceiling. If any part of the exhaust fan is within the box, you should GFCI protect the fan as per the installation instructions.

If it makes you feel safer, then by all means GFCI protect the fan.

  • Then "Why not GFI and AFCI protect everything in the house?" – Speedy Petey
    – Mazura
    Oct 6, 2014 at 10:28
  • 3
    @Mazura You surely could if you wanted to. Codes are MINIMUM safety standards.
    – Tester101
    Oct 6, 2014 at 10:34

I would be less worried with the strict interpretation of what the code requires here than the reason that the code exists. An exhaust fan's purpose in a bathroom is to remove moisture from the room. Moisture and electricity generally do not mix safely, so I would put it on a GFCI protected branch regardless of whether it is required by code in your jurisdiction.

  • 2
    If the fan is installed, wired and grounded properly what great benefit would this serve? Do you regularly go up and work on your bath fan while it or you are wet? I am curious as to what you think the danger is. IMO the GFI requirement (from the manufacturer BTW) is due to the fact that many shower areas have soffits above them making the fan within reach while in the shower. Oct 6, 2014 at 1:52
  • @SpeedyPetey - It would serve the purpose of being protected against a ground fault in the event that condensation provided an alternate ground path through the case. Granted this isn't a horribly likely scenario, but swapping in a GFCI breaker for the bathroom would reduce that risk from slim to none.
    – Comintern
    Oct 6, 2014 at 1:58
  • 2
    If the fan is properly grounded this would be impossible. There are hundreds of "what-ifs" with regard to home wiring. Where do you draw the line? Why not GFI and AFCI protect everything in the house? Oct 6, 2014 at 2:00
  • 6' from a water source is code IIRC, if everything in a bathroom must be on GFCI, IDK but it should be. A shower head with a wand can go pretty far. @SpeedyPetey
    – Mazura
    Oct 6, 2014 at 2:03
  • 1
    No, there is NO "6 foot from a water source" code. And I'll ask you as well, WHY should it be? Even if a shower head sprayed water on a fan, even if it were running, what do you think would happen?? All these urban legend codes and suggestions are created by people who don't know the actual codes or the reasons for them. Again, if you want to knee-jerk react to every even slightly potential "water and electricity" interaction go right ahead, but please do not give answers and make suggestions based on them. Oct 6, 2014 at 2:24

Your description makes it clear that the fan is not directly over the tub or shower, so no GFI protection would be required.

As Tester says though, if it makes you more comfortable you can GFI protect it. Personally I would not bother.


Consider the following: after turning on the hot water in the shower to make some steam, I witnessed an electrical arc in the hotel this morning from the vent fan housing to the shower curtain rod, about 6 inches, that probably would have killed me had I not turned around to get a washcloth from right outside the door and instead pushed the shower curtain back and stepped inside. The fan did die and the arc made the room smell of ozone.

This is a case of the "box" being extended outside the tub boundaries by a curved hotel shower rod now bisecting the vent housing. The vent housing was also within reach of someone standing in the tub by raising your arm.

If it's in a "wet" room and can be touched by someone with wet, bare feet, use a GFCI circuit for the outlet or appliance.

Be careful out there!

  • 1
    Arc jumped 6" ? That sounds like an awful lot of voltage for domestic wiring, even given the extremely moist air. Jul 24, 2019 at 19:17

No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans shall be located within a zone measured 900 mm (3 ft) horizontally and 2.5 m (8 ft) vertically from the top of the bathtub rim or shower stall threshold.

  • That Code cite does not apply to bath (vent) fans Nov 20, 2021 at 6:19

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