Electrical Breaker

[texasman]

Can a breaker trip without showing the obvious sign it tripped. My Nest thermostat showed it was getting no power and the breaker didnt look tripped. Turned it off and back on and all is back to normal. Should I just replace the breaker they are all 30+ year old. Thanks.

 

[Bretny]

Are need thermostats 120v or low voltage from your heater?

 

[slow]

what kind of breakers do you have? Some have obvious tripped indicators, such as Square D QO with Visi-Trip I have never seen a need to replace a breaker just based on age, in the rare case they have an issue, just replace them at that time.

 

[03.]

Probably not a lot of use to you but in Australia we have breakers that trip but still look like they are on. Have to turn to off to reset then on again. Breakers were made around 40 years ago.

 

[mike93lx]

Your nest is powered by the furnace at 24v, not a 120v circuit.

 

[Norcal]

What brand of circuit breakers? Older GE could be tripped but if you did not know what to look for, it would not be noticed.

 

[Terry D]

Yes breakers can do that, Sometimes they can stick and the lever will not go in the center position. First thing I do when I have lost power and none of the breakers looked tripped, I run my finger down each side of the breakers lightly touching the handles. This will push a tripped breaker in the center position. This doesn't happen often, but it has happened. Another way is just to check voltage at the breaker with a meter. The important thing is to find out why it tripped, if it does is again, and it is a nuisance trip, then it is time to replace the breaker.

 

[Kevin Essiambre]

Your nest is powered by the furnace at 24v, not a 120v circuit.

You are correct, but what powers that 24 volt circuit? That's right, a 120 volt circuit breaker.

OP, I have seen circuit breakers stick before when they trip. I would at least change the one for the furnace. The furnace is what supplies the thermostat with power.

Sent from my new phone. Autocorrect may have changed stuff.

 

[alfredeneuman]

I would at least change the one for the furnace.

This would be a mistake without testing the breaker first (it may be a bad transformer)

 

[Kevin Essiambre]

This would be a mistake without testing the breaker first (it may be a bad transformer)

Depends on the furnace. It may be a bad circuit board that will cost as much as a new furnace.

Sent from my new phone. Autocorrect may have changed stuff.

 

[mike93lx]

You are correct, but what powers that 24 volt circuit? That's right, a 120 volt circuit breaker.

OP, I have seen circuit breakers stick before when they trip. I would at least change the one for the furnace. The furnace is what supplies the thermostat with power.

Sent from my new phone. Autocorrect may have changed stuff.

No ****, huh? Had no idea. Point is that unless the furnace was also off, it isn't a breaker issue.

 

[wyliesdiesels]

You are correct, but what powers that 24 volt circuit? That's right, a 120 volt circuit breaker.

OP, I have seen circuit breakers stick before when they trip. I would at least change the one for the furnace. The furnace is what supplies the thermostat with power.

Sent from my new phone. Autocorrect may have changed stuff.

Thats not the proper way to troubleshoot this

 

[Terry D]

With out knowing what furnace he has, we dont know if it even has a board. If it does, most likely a bad transformer would blow the control fuse. Sounds like when he reset the breaker, everything is fine now. So no direct shorts. Could be a motor starting to go to ground. Plus there could be other things on a same circuit, not necessarily a dedicated circuit. The 24 volt doesn't necessarily even have to come from the furnace. I personally have a hydronic heating system with a separate air handler for central air. I only use one thermostat for both, but the 24 volt comes from the air handler. He needs to give more info if it keeps tripping

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[alfredeneuman]

If it does, most likely a bad transformer would blow the control fuse.

Many heating and doorbell transformers don't have external fuses.
The "fuse" is an internal temperature sensor that will trip the current to the transformer if it overheats.
I agree we need further info on the system

 

[Norcal]

The OP did state that everything was back to normal after resetting the breaker, but it would be good to know why the breaker tripped.

 

[teamextreme]

And to reiterate the answer to his original question, yes, breakers can and often will trip without showing any visible signs they are tripped. Depends on the manufacturer how likely this is to happen. I wouldn't replace a breaker just because of this. As others have said, find out what caused it, or more likely what I would do is not worry about it unless it starts happening again.

 

[alfredeneuman]

The OP did state that everything was back to normal after resetting the breaker

That's what I get for not reading the post carefully :tard:

 

[Terry D]

Many heating and doorbell transformers don't have external fuses.
The "fuse" is an internal temperature sensor that will trip the current to the transformer if it overheats.
I agree we need further info on the system

I was referring to the automotive style control fuse on the boards in the furnace. We dont know if is that style or old school style, which like you said, no protection for the transformer.

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[TheVodkaMan]

Interesting...

 

[texasman]

Ok hoping I can answer all the ones I can from who posted. It is a Rudd system inside and out. Its done this one time before. The breakers are from 1985. So no visible indicators of it being tripped just that its "popped" out for lack of better words. Last night I just turned it off counted to 5 and flipped it back on all was back to normal. Just dont know if its work just swapping out for new breaker. If its the case they do need to be replaced cause of age. Would it be worthwhile to replace all of them. Breakers are only like $3.50 each, a little more for 220 breakers.

 

[brewchief]

So was the breaker actually tripped or was it just a problem with the Nest that turning the power off and back on fixed? Random problems with Nest thermostats are not exactly uncommon.

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[mike93lx]

So was the breaker actually tripped or was it just a problem with the Nest that turning the power off and back on fixed? Random problems with Nest thermostats are not exactly uncommon.

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Unless the furnace was also off, it wasn't a tripped breaker