Recently during a storm a circuit breaker switched off half of our home's lights and sockets. Thinking it was due to moisture we waited for the house to dry and then reset the breaker. It would stay on for a while but then flip back off. Finally it would no longer switch on. We called an electrician who said there was a short but it would require troubleshooting to identify the exact location. He offered us two options:

  1. Troubleshoot the short only ($350)
  2. Split the circuit ($1200)

We counted all the lights and receptacles on the circuit and found 24. The 15A breaker should only support a load of 1400W (15A * 120V = 1800W * 80% max load). So it definitely seems there are too many junctions on the one circuit.

Is it possible to split the circuit without running additional wire through the house? The electrician seemed to indicate it was but I wasn't clear on his explanation. He mentioned using pigtails but I'm unsure if he meant pigtail connections or AFCI breakers.

I don't mind spending more money but I'd like to get the root problem solved. Would splitting the circuit and using two 20A breakers be sufficient? If so, what changes to the wiring are necessary?


This is the breaker box: breaker box

This is the circuit breaker in question (OFF is the shorted circuit): circuit breaker in question

  • 1
    You could split it by running a minimal amount of wire, but I don't see how its possible without running any wire unless it was run with too many wires to begin with. Did he really mean there wouldn't be any new wire runs? Also, if it's a 15A circuit now, you can't make it a 20A without replacing ALL the wire.
    – JPhi1618
    Commented Dec 9, 2019 at 16:17
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    Have you tried unplugging everything that is plugged into it? Does the circuit breaker have a TEST button on it? Does it serve any outdoor outlets? Commented Dec 9, 2019 at 20:42
  • @Harper-ReinstateMonica yes we've unplugged everything. No, there's no TEST button, just a ON/OFF switch. Yes, there are some outdoor outlets connected but they have never worked. Commented Dec 9, 2019 at 23:53
  • What make and model is the breaker in question, and what make and model is the breaker box for that matter? Commented Dec 10, 2019 at 0:08
  • 1
    @ThreePhaseEel I've added pictures. Commented Dec 11, 2019 at 16:16

2 Answers 2


You will need at least 1 new circuit, and to break the circuit and install that new 15amp circuit (I am guessing the wiring is 14 awg). You can get things to work by removing some of the load but you probably have figured that out.

If you have room adding a breaker is not that hard but you will need to do some reading and ask more questions.

You cannot use 20 amp breakers on 14awg wire--you have to stay with 15 amp breakers unless the wiring is 12awg.

I doubt you have a short just a simple overload, so you will need to run a new circuit.

To prove it’s not shorted, turn the lights off, unplug things, then reset the breaker. Now turn each room on then off and start plugging things in. If a single device like a electric heater is on the circuit, just leave that unplugged and everything else will probably work.

  • If you have conduit your job will be easier.... +
    – JACK
    Commented Dec 9, 2019 at 17:31
  • We did remove all the load from the circuit and the breaker would still trip. I think we tried too many times and the breaker no longer stays in the ON position at all. The electrician did do some checks with a multi-meter in the circuit box and said it was a short which seems reasonable to me. Commented Dec 9, 2019 at 17:45
  • 1
    Ok with the loads removed you probably do have a short . Could you let us know the brand of breaker panel there are a couple out there that could be the cause, once we know the brand we can provide more trouble shooting tips.
    – Ed Beal
    Commented Dec 9, 2019 at 20:29
  • @EdBeal make and model info above: diy.stackexchange.com/questions/180004/… Commented Dec 10, 2019 at 15:00
  • That sounds like a double tandem but the part number doesn’t match , but a square d panel makes it less likely the problem is in the panel, if you have metal boxes there actually could be a short just about any place, this would be an area where I would want to cut the circuit in half and install a new circuit to the 2nd half and see which one has the short, then the shorted side open the circuit at a junction at 1/2 of what is left , each time checking to see which half has the problem , in 4 breaks you will have it narrowed down to 3 devices or conductor runs. This is how I would proceed.
    – Ed Beal
    Commented Dec 10, 2019 at 16:37

I'd like to get the root problem solved

your pic looks to be a classic case of a too small load center that has outlived is usefulness. Seeing gargage disposal and dish washer and AC and stove any whatever else which are supposed to be on their own breaker, you simply don't have enough space in the existing load center. Then seeing use of tandem breakers.

consider calling around and get pricing to redo your load center with the longest Square D load center that's available or what will fit there giving you breaker space. Then that install can coincide with fixing everything else, possibly upgrading to 200amp service, etc. A new load center box is $107

verify with an electrician/installer the quality of their work and what outcome you expect. you don't want a brand new box installed with magic marker then written on it again like in your pic. someone that's good will identify all the existing circuits, and identify all the problems with and provide solutions.

  • Some of the labels are incorrect. There is no AC. We bought this house a couple of years ago and it came like this. Our electrician has agreed to put in two more breakers to distribute the load of the shorted circuit. I will ask him to put in a new load center if necessary. I would hope a well-rated licensed electrician would make the right call. Commented Dec 11, 2019 at 20:25
  • We already have identified all the junctions on the shorted circuit. Would it be worthwhile to make a wiring diagram by flipping each breaker one at a time and observing what goes off? We could also trace the lines in the attic. Commented Dec 11, 2019 at 20:27
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    I would hope a well-rated licensed electrician would make the right call. Don't be so sure, get first hand references and some pics and proof of his past work. A relative wanted me to positive review his business on facebook (which i never used) to give u an idea so don't assume anything.
    – ron
    Commented Dec 11, 2019 at 21:09
  • Would it be worthwhile to make a wiring diagram... do you like things been accurate and neat? Depends on your standards.
    – ron
    Commented Dec 11, 2019 at 21:11
  • it would help in cases like this and for future reference. Seems whoever did the electric before didn't do a good job. Commented Dec 11, 2019 at 21:16

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