Home Electrical Question

If my bathroom vent fan, and bathroom heat lamp, which normally turn on via two separate light switches, start coming on only together, regardless of what switch is on, is that "get it fixed when ya can" or "burn your house down" bad?

 

Usually there are two separate plug ins that are fed from separate wires in the unit. I can't really imagine a way that they would start operating simultaneously unless someone was messing with the wiring.

Has anything been worked on recently?

 

I’d look into it. Assuming the switches are adjacent to one another, depending on how they’re wired, it sounds like an internal short somewhere.

 

It should be pretty easy to take the fan apart with basic tools. It wouldn't be hard to open up and check the condition of the wiring. If there's a short, it's most likely in the fan or the switch box.

 

No work has been completed but we have had extremely cold weather unusual for the area so maybe somehow something happened?

It's really strange. Even weirder is if my wife leaves the light on, the fan will randomly start and stop every once in a while.

It's either an electrician or priest job haha

I'll pull apart the fan and switch and see what the heck.

 

Remember to turn off the circuit!

That's definitely some peculiar behavior.

 

I’m guessing that the switch is the problem.

 

I have one too. On a designated circuit. The switch went I ordered same exact thing and replaced it. Or you could get an oil heater and burn all your used motor oil? I hear thats what they do with it.

 

Chances are all of your switches share a common hot and one of the switches has failed. Turn off the circuit, test for the absence of voltage, and replace the switch. Make sure you remove the wires one at a time and take photos before you begin.

 

@PVT Pablo , I should have asked earlier, but are the fan and heat lamp in the same housing?

 

It is indeed. It's this guy right here

https://www.lowes.com/pd/Broan-Fan-...-70-CFM-White-Bathroom-Fan-and-Heater/3551198

 

Did you do any poking around yet?

 

Not yet, I've got a surprise work trip starting tonight through the week so it'll be a next weekend project unfortunately.

I do think this may be a possibility. The area of exhaust is extremely mossy (rental) and all that moss buildup freezing and thawing could of done something.

 

If you're renting, could you ask the landlord to have an electrician look at it?

 

Normally, definitely.

Landlord and I have kind of a unique agreement for small repairs.

 

This is likely why the fan is starting automatically when just the lamp is on. From the specs:

• Automatic thermostat recycles fan to keep housing temperature within safe limits
  

 

Hmmm... the thing that makes me think it's not this is that if the fan turns on, the heat lamp does too, which would be counter intuitive

 

This is what I was referring to:

“Even weirder is if my wife leaves the light on, the fan will randomly start and stop every once in a while”

That sounds like some sort of designed cooling. I get the other issue and would definitely look at the switches. Is it two separate single pole switches? Or a double switch in a single box?

 

Ah gotcha. Hmm I will have to do more research into this for sure. Good point.

I haven't broke into the switch yet to see how it's wired but I'll report back. From the outside it's two switches, one for light, one for fan.

 

I think @Beachguy could be onto something, though. It's possible that whatever device causes the fan to run to regulate the temperature has failed in some way, causing both things to run simultaneously. That's the first thing I would look into.

 

Is it operated by wall switches, or switches attached to the unit itself? Like are there switches on the wall like regular light switches?

 

From the pdf installation instructions

 

I think the mystery has been solved. I'm going to run it with just the lamp on and see what happens.

Damn you guys are smart

It has two wall switches

 

Here's the one I have. It dehumidifies the bathroom instantly. I use it all summer to every time I take a shower. It needs its own breaker.

 

SOLVED. It's a weird design but if the heat lamp is left on and the thermometer goes into safe mode, both the lamp and the fan come on regardless of which switch is on. I tested this on the other units in the home and sure enough, they all do it, unless they're all wired wrong haha.

Thanks all for the input.

 

If they separated them there would always be the possibility that one (the lamp) could work without the other (the fan). I was hoping you would post an update and glad it’s all good.

 

This makes perfect sense. Thanks for the update!