# Bath fan tripping the breaker



## Kat2014 (Feb 6, 2020)

Installed new bath exhaust fans yesterday. First one was fine. Second one (identical) not so much.  I turned the power back on and the fan and lights came on as normal, but when trying to turn the fan off, the breaker pops.
(There was a fan there before; this is a replacement - it was wimpy, but caused no electrical problems) I seemed to hear a sound from the actual wall switch as well as the breaker popping - I thought it might be arcing - a very old switch, so I swapped it out. Same problem.

I disconnected the wiring harness on the fan for now, so I can still have lights in the bathroom till I figure this out. There was a fan already in this location, and I doubt this one has a much higher electrical draw - not so much higher as to pop a breaker. I plug some high draw things into this circuit (hair dryer, etc) and there is no problem. Maybe I am looking at a problem with the fan itself?


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## Snoonyb (Feb 6, 2020)

Seperate the fan/light away from that circuit, to a light circuit.


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## Jeff Handy (Feb 7, 2020)

I have also installed bath exhaust fans that nuisance trip on a gfci, if that is what you really mean.
I think it is just an issue with electrical noise or surges as the motor is winding down. 

Either replace the fan motor and hope it stops, or remove the fan from a source of gfci switched current.


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## afjes_2016 (Feb 7, 2020)

If the breaker trips the exact moment you flip the switch to the "off" position then you more than likely missed wired something. A breaker tripping immediately indicates a dead short. If a breaker takes some time to trip then it more than likely indicates an overload on the circuit.

Check you wiring again. Look at the diagram of the unit that came with it. You must have wired something incorrectly.


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## Kat2014 (Feb 7, 2020)

Thanks - I will check it again today!


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## Jeff Handy (Feb 8, 2020)

Is this tripping a gfci breaker, or a gfci outlet, a gfci switch, or a regular circuit breaker?

Please confirm.


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## Kat2014 (Feb 8, 2020)

It trips the gfci outlet and a regular circuit breaker.


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## afjes_2016 (Feb 8, 2020)

Kat2014 said:


> It trips the gfci outlet and a regular circuit breaker.



Please clarify: You state it trips the GFCI receptacle along with the regular breaker. When you say it trips the GFCI receptacle does it actually trip it or does the GFCI receptacle just not have power because the regular breaker trips. When you reset the breaker do you also have to reset the GFCI receptacle or does the receptacle have power without resetting it by pushing the reset button when you reset the breaker.

There is a difference between the GFCI tripping and having to reset it with the reset button and the GFCI losing power because the regular breaker trips.


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## Jeff Handy (Feb 8, 2020)

If the “regular circuit breaker” is an arc fault breaker, they are known for nuisance tripping. 

Otherwise, I would replace the fan motor and see  what happens.


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## Kat2014 (Feb 8, 2020)

Yes, it "actually" trips the GFCI outlet and the regular circuit breaker at the box at the same instant.
I have to flip the breaker back on AND reset the GFCI outlet.


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## Jeff Handy (Feb 8, 2020)

Time for a new fan motor.


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## Kat2014 (Feb 8, 2020)

The unit is brand new....I bought 2, and the other works fine. Is it common to get a lemon in high end bath fans?


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## pjones (Feb 8, 2020)

Jeff Handy said:


> Time for a new fan motor.



Sounds like the fan motor works. It only happens when the switch is activated. I would suggest replacing the switch first if you don’t have the abilities to find the fault using a meter.


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## pjones (Feb 8, 2020)

Kat2014 said:


> The unit is brand new....I bought 2, and the other works fine. Is it common to get a lemon in high end bath fans?



Anything is possible.


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## afjes_2016 (Feb 8, 2020)

Lets keep in mind everyone what the OP stated about the fan

"First one was fine. Second one (identical) not so much. I turned the power back on and the fan and lights came on as normal, but when trying to_ turn the fan off_, the breaker pops." Which means the fan runs fine.

This occurs when the OP _turns the fan off_. _*So to me this states there is a mis-wire and causing a dead short.*_ Would not matter what type of breaker the OP has installed. A dead short will trip a regular breaker, AFCI breaker, GFCI breaker or a dual function AFCI/GFCI breaker.

Kat2014 please confirm that the fan runs fine but when you go to shut the fan off (turn the switch to off) that is when the breaker trips. If this is the case that when you turn the fan off it trips the breaker you need to check how you wired it. Give us some details of the wiring because it is obvious that you did not wire something correctly when hooking it up.


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## Kat2014 (Feb 8, 2020)

I appreciate all the comments, but I cannot give further wiring details at the moment,. We have some storm damage from the system that came through on Thursday night, and I have my hands full taking care of that.

But yes, the fan runs fine, it trips everything when shutting it off. The switch has already been replaced, and I will check the wiring after I get the storm damage taken care of.


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## Jeff Handy (Feb 8, 2020)

Swap the motors between fans, see if the problem moves with it.


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## afjes_2016 (Feb 8, 2020)

Jeff Handy said:


> Swap the motors between fans, see if the problem moves with it.


Jeff Kat2014 said the fan runs fine. Read my reply above (post #15). _It is when Kat turns the fan off that the breaker trips._
This clearly indicates that _Kat2014 did not wire it correctly_ when hooking it up. There is no need to swap fans or anything else.


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## Jeff Handy (Feb 8, 2020)

The problem and diagnosis might be obvious to you, but others with experience have valid opinions and input. 

No one appointed you king of the forum, we are free to suggest ideas that have worked for us in similar situations.


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## Jeff Handy (Feb 8, 2020)

The gfci outlet might be wired wrong also, they often are.


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## afjes_2016 (Feb 8, 2020)

Jeff Handy said:


> The problem and diagnosis might be obvious to you, but _others with experience_ have valid opinions and input.
> 
> No one appointed you king of the forum, we are free to suggest ideas that have worked for us in similar situations.



Jeff first of all I am not going to get into an argument with you - not my cup of tea!

I was simply bringing to all respondents of this tread including yourself that the OP stated in his first post that the issue happens when the switch if in the off position *not* the on possition which is something that can be overlooked easily.

_Your_ signature states the following - "Professional Handyman, NOT a Licensed Pro" - Well I am a "Licensed Pro" - I took years of electrical classes in a good trade school and was a certified and licensed electrician until I retired because of physical issues so let's not go there Jeff.

I was not stating that the replies so far were incorrect at all (including your suggestions) - again, I was just trying to bring to everyone's attention (something that can be overlooked easily) that the problem happens when the switch is in the "OFF" position not the "ON" position - that's all. Thus there is very possible a mis-wire that Kat2014 did.

Your post #20 even confirms this theory that there may be a mis-wire. "The gfci outlet might be wired wrong also, they often are."

I never claimed to be "king of the forum". I have been a member of this forum much longer than you have been and have given many OPs helpful and useful information that is within code and safe.

Let's get back on the right track here and attempt to help Kat2014 with this problem once he deals with the other issues of the storm damage.


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## pjones (Feb 8, 2020)

afjes_2016 said:


> Lets keep in mind everyone what the OP stated about the fan
> 
> "First one was fine. Second one (identical) not so much. I turned the power back on and the fan and lights came on as normal, but when trying to_ turn the fan off_, the breaker pops." Which means the fan runs fine.
> 
> ...



You make a good point, something is certainly wrong, but the OP hasn’t provided sufficient information to come to that conclusion yet. 

The OP hasn’t specified if they changed any wiring on the switch or elsewhere in the circuit. They also haven’t said if the previous fan had failed or stopped working for any reason. We don’t know if the fan is protected by GFCI or if there is simply another outlet that is on the same circuit but ran in parallel to the fan. It’s possible the outlet trips because the circuit loses power and is throwing a red herring into the mix. 

The point that you brought up that I like is that sometimes it can be easy to assume people understand the basics of electricity and that allows things to be overlooked. Incorrect wiring is a possibility that shouldn’t be thrown out. But with the limited info that we have of this circuit it isn’t the only possibility out there. 

To the OP, can you clarify the circuit a little better and let us know what level of understanding you have about electrical circuits, and what test equipment you have access to. Will the circuit trip when the breaker is reset with the fan switch in the off position? If not will the breaker trip when the fan is turned back on? Those sorts of details will help us help you. 

Jeff’s suggestion to swap the blower assemblies is a simple and easy test to determine the motor if the OP doesn’t have an electrical meter of some sort.


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## Jeff Handy (Feb 8, 2020)

You stated that there was no need to swap fans or anything else. 

Thereby declaring my suggestion wrong and unnecessary. 

That is what I have a problem with. 

Since that method of swapping identical parts has helped me solve many head scratchers. 

And others I know often use this technique as a diagnostic tool.


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## bud16415 (Feb 9, 2020)

We all need to calm down a little here. Saying with my Admin. pants on. 


That being said and I hope that is all that will need to be said on the topic.


Electrical troubleshooting is tough on here as each person coming with a question has a different level of abilities. I would just stick the fan on my workbench and wire it up with test leads and make sure it worked properly but that’s not what I would suggest for the OP.


As to @afjes_2016 thoughts, I’m trying to think of a case where a switch passing power in the on position can cause a dead short when opened. Maybe a defective switch but having it happen with both the old and new isn’t logical. The only case I can think of is if the OP picked up a 3way switch by accident and wired it in weird. Every switch wired wrong that caused a dead short I can remember caused the fault when it was turned on.


Sounds like the OP will be busy a few days and then we will figure it out.


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## Johnboy555 (Feb 10, 2020)

Just being the "Devil's Advocate" ...What if there was a 3 way switch installed prior??  (Just an off the wall  thought) 
In 40+ years of installing and troubleshooting I've never seen a problem like this.
Without actually seeing the wiring I'm at a loss.  I would have pulled the switch out and touched the wires together and seen what happens. 
Way to step in Bud
Sorry ..wrote before I read your post.


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## bud16415 (Feb 11, 2020)

Johnboy555 said:


> Just being the "Devil's Advocate" ...What if there was a 3 way switch installed prior??  (Just an off the wall  thought)
> In 40+ years of installing and troubleshooting I've never seen a problem like this.
> Without actually seeing the wiring I'm at a loss.  I would have pulled the switch out and touched the wires together and seen what happens.
> Way to step in Bud
> Sorry ..wrote before I read your post.




Nothing surprises me and I have found a 3way switch used as a regular switch before with nothing attached to the other carrier screw. So who knows. We will have to wait for the OP to take some pics and show us.


Because we all know what happens when we assume.


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## Kat2014 (Oct 21, 2020)

Just a quick update - the bath fan itself was fine - turns out the "brand new" wall switch was faulty.  Swapped it out and everything works fine now. It was the last thing I expected, lol.


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## oldognewtrick (Oct 21, 2020)

Thanks for the follow up!


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## kok328 (Oct 24, 2020)

If the fan is wired into the GFCI, make sure it's wired to the LINE side of the outlet.  GFCI's get touchy with age.  Might need to change the GFCI if you want to use the LOAD side of the outlet.


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## afjes_2016 (Oct 25, 2020)

Thanks for the update kat2014 and glad you got it solved.

Hope all is well with the storms you had a while back (mentioned in this thread). Hope all are safe in your family.

Be well


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## Kat2014 (Oct 25, 2020)

kok328 said:


> If the fan is wired into the GFCI, make sure it's wired to the LINE side of the outlet.  GFCI's get touchy with age.  Might need to change the GFCI if you want to use the LOAD side of the outlet.


Yes, the GFCI was changed out as well - when all this started.


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## Kat2014 (Oct 25, 2020)

afjes_2016 said:


> Thanks for the update kat2014 and glad you got it solved.
> 
> Hope all is well with the storms you had a while back (mentioned in this thread). Hope all are safe in your family.
> 
> Be well


Well, we recently got a new roof put on, and that was an expensive but wonderful relief - no waking up to the sound of drips during a storm anymore!!


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## zannej (Oct 25, 2020)

I'm very glad you got the problem fixed & it was something simple. Sorry to hear you got a bad switch but at least you figured it out. Also sorry about the storm damage but glad you have a new roof. My area may be about to get hit with hurricane #3 in a few days so I can sympathize.


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