One of my circuit breaker trips instantly.

I try to reset it but it trips immediately and trips the breaker under it too.

I can reset the break next to it and it is fine until I try to reset the problem breaker again.

Could the breaker itself be bad? and if so could I swap it out myself?

How would I find which outlets, light, fans are powered by this possibly bad breaker?

Update: I added a video showing the exact issue.


  • 2
    Did you make any changes to the electrical system that caused the breaker to trip? If you follow the wire terminated at each breaker (the "bad" one and the one below), are the wires part of the same cable (you may have to remove the panel cover to determine this, do so with care)? Do the two breakers look like they are somehow connected?
    – Tester101
    Commented Oct 3, 2013 at 16:50
  • 2
    The breaker might be bad, and you might be able to change it yourself. As for figuring out which receptacles, lights and fans are fed through the breaker. That's easy. It's all the things that stop working when the breaker is OFF.
    – Tester101
    Commented Oct 3, 2013 at 16:53
  • Do the wires connected to both of those breakers go out to the same cable/conduit? Commented Oct 3, 2013 at 18:11
  • 1
    Spending way too much time in my attic this summer redoing some electric I noticed a junction box that had three different circuits in it. One dead-ended there, one was for some lighting and traveled on, and another for kitchen stuff that traveled on. The hots for two of the circuits were laying on top of each other. They were in a proper nut but if they came out we have your situation.
    – DMoore
    Commented Oct 7, 2013 at 15:19
  • 1
    Assuming that B1 is the top breaker and B2 is the bottom breaker, what happens when B2 is off and B1 is turned on. You've shown what happens when B1 is turned on when B2 is on, but not when it is off. Commented Nov 7, 2013 at 13:36

6 Answers 6


Somewhere in the circuit there is likely a low resistance connection between the two legs. The most likely culprit would be a split duplex receptacle that was replaced, and the tab between the upper and lower sections were not removed. Another likely cause would be a staple, nail, screw, etc., that penetrates both cables.

With both breakers off, check continuity between the ungrounded (hot) conductors of each circuit.

  • Turn off both breakers.
  • Set your multimeter to continuity mode, or the lowest resistance setting.
  • Touch one probe to the lug of one breaker, and the other probe to the lug of the other breaker.

With the breakers in the off position, you should read infinity (or open). If you get a reading, it means that these two conductors are connected somewhere. If the reading in not close to 0, there could be a 240 volt load connected between the legs. If the reading is near 0, you have a low resistance short between the legs.


You have a back feed from one circuit to the other. It would appear power is leaving from one circuit breaker and somehow finding its way back to the panel on a different circuit. Consider back tracking any areas where electrical work was done. Maybe a junction box where both circuits meet for some reason. If all wires tied together, that would create a back feed. Again, if any work has been performed recently, I would look there first. Separate the wires and attempt to turn both circuits on. If the circuit stays on, you would more than likely have both hots there and have 240 volts as well.


The video shows clearly that B1 and B2 are somehow interconnected. Figuring out how is the trick.

Step one is to determine what exactly B1 and B2 control. You could gain some help from a tracer tool such as the Klein ET300, but really a lamp works just as well.

  • Make a list of every outlet and light affected by these breakers, post this data. Unplug everything.
  • Turn off the main, remove the panel cover and post some pictures.
  • Now turn the main on, and B1 off. Measure the voltage on the black terminal? Hot or not?
  • Now turn the main on, and B2 off. Measure the voltage on the black terminal? Hot or not?
  • You can swap the two breakers if you like to eliminate the chance that B2 is defective.

An electrician would likely brute force finding the problem. The only other tool I can think of that would help is a line length tester, which can give you a reading in meters for the length of a cable to a resistance point. But the tool is too exotic and might not even work in your case.


I'm betting that B1 provides power to the top outlet of a receptacle (probably on your kitchen counter) and B2 provides power to the bottom outlet. At some point that receptacle was changed (maybe you decided to change out the old looking receptacles and replace them with new snappy looking decora outlets?) Whoever changed them out didn't realize it was a split receptacle and didn't clip the bar between the terminals. You can probably have either breaker on at a time but not both.. yes? Happened to me when I moved into my current house


I had the exact same problem. Like other posters are saying, the circuits are probably connected (probably intentionally in my case). The electrician who installed a new panel recently should have used double breakers for the circuits but used single breakers instead.

I'm going to get this single breakers replaced with double breakers, but in the meantime the easiest fix is to just reset both breakers simultaneously, as if they were double breakers. Works great, no hassle and doesn't cost a thing.


Can you pop the cover of the main panel? It is impossible to tell without more info, but what could be happening is someone wired a 240V appliance (requiring a double breaker) to two individual breakers. If there is a problem in one of the circuits, it could be tripping both breakers. Alternatively, as others have mentioned, black wires from both breakers are touching somewhere (either in the panel or somewhere else). In either case, removing the panel cover should give you more info

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.