We had an addition built and the dufus wired too many outlets into a 20 amp breaker. We have to run a couple of electric heaters occasionally in 2 different rooms and they always trip the breaker. Can we just have an electrician replace the 20 amp breaker with a 30 amp breaker? Is this likely to solve the problem?

  • 12
    More likely to burn down your house. Better solution is to split the circuit into two or do not try to use so much power at a time.
    – crip659
    Jan 5, 2023 at 16:48
  • 32
    Living in a House Lesson #1: If a breaker trips, assume it's doing its job, not that some "dufus" didn't do his job.
    – FreeMan
    Jan 5, 2023 at 17:29
  • 4
    "Can we just have an electrician replace the 20 amp breaker with a 30 amp breaker?" - If an electrician satisfies this request then you'll be warm for the rest of your life. Please don't out-dufus the dufus.
    – MonkeyZeus
    Jan 5, 2023 at 19:28
  • 2
    Despite some of the sarcastic comments here, licensed electricians sometimes, for whatever reason, don't do things right. The Master Electrician (and his journeymen) wired my new (2011) garage with #14 cable but put 20A breakers in the panel. Go figure.
    – SteveSh
    Jan 5, 2023 at 23:12
  • 4
    If a properly sized breaker trips, it's not telling you that the breaker is too small. It's telling you that you are exceeding the limit of all the wiring which won't change just because you upsized the breaker.
    – DKNguyen
    Jan 6, 2023 at 1:56

7 Answers 7


No. and double NO! circuit breakers are there to protect the installed wiring on branch, convenience circuits and sometimes hard-wired devices. You CANNOT simply upsize a breaker just because it's doing it's job!

You could run a separate circuit if feasible. or ....

Have you considered using lower wattage heaters? Or heaters that have a "LOW setting"? They may have to run longer, but may not trip your breaker.


No! no no no! no! You need to run another circuit if you have too many loads for the 20 amp breaker.

The current circuit uses a 20 amp breaker, because 20 amps is the maximum current the wires can safely handle.


It will possibly burn your house down. Especially if that dufus followed code and use a 12 gauge wire for a 20A circuit. That wire will overheat when you put a load on it that would trip a 20A breaker.

Instead you should run an extra circuit to power the heaters/split up the outlet circuit.

  • It is 12 ga wire. I bought it myself. He was supposed to run separate wires and breakers for each room. He cut corners and just ran them all together. I had the space in the panel box and I bought 4 breakers so that he could do that. He only used 2 of the breakers...one for the laundry room and one for the hall, bathroom and bedroom and outside outlets.
    – Chuck
    Jan 5, 2023 at 19:25
  • 2
    Just a note that as new circuits, one should be dedicated for bathroom outlets only (more than one bathroom ok I think). If NEC code applies in your area, having hall/outside/bathroom/bedroom outlets on the same circuit probably violates it. There are also special rules for outside outlets.
    – Armand
    Jan 5, 2023 at 19:30
  • 1
    Why would an electrician or anyone working for you cut corners. Only people spending the money want corners cut to save money, not the people you pay to do the work, more work=more money for them.
    – crip659
    Jan 5, 2023 at 19:55
  • 4
    That's no "electrician" in my definition. He should have known at least that bathrooms required dedicated 20 amp circuits. Also, best practice is a dedicated circuit for the laundry room (I'm not sure it's required, but it's good). Then you still would have had 2 more circuits avail, one for each bedroom. Jan 5, 2023 at 22:33
  • 2
    @crip659 unless they can do less work for the same money!
    – user253751
    Jan 6, 2023 at 1:35

Turn the heaters DOWN!

All space heaters are 1500w on high. That is 12.5 amps. However, most have a "LOW" setting that is 700-800 watts, or 6-7 amps.

See how to get "under 20" out of that? Just use "Low"! (remember you have to account for everything else on the circuit too).

My winter cottage has a 30A/120A main breaker and two 20A branch breakers. That's right, the whole house. We use space heaters a little, and as you can guess, we run ONE on high or TWO on low. My sweetie isn't me, and yet, we have this down pat. I start to make toast, sweetie kicks the space heater to "low". Apparently we know what we're doing, because we've had 3 breaker trips in 15 years here.

Breakers protect wires in the walls from fire

They already used the largest breaker that is safe. (assuming the wiring is yellow Romex; if it's white then they already oversized the breaker).

Installing a larger breaker is the same thing as installing NO breaker! (that is a thing, it's called a "Subfeed Lug Kit"). If you want to do that, that's between you and your insurance company LOL.

Upgrade your installed HVAC

First, you shouldn't be using space heaters as primary heating. If your additions's main (built-in) heating is inadequate, upgrade it. If you didn't spec any and your plan all along was to use plug-in space heaters, that's a waste of money. (I bet you thought I was going to say something else lol). Seriously, because of the cost of those space heater! (I bet you thought I was going to say "electricity" but that too). It's also unbelievably unsafe, and insurance won't pay because the machine's instructions specifically say not to run it unattended.

If your addition needs more HVAC, let me clue you into the latest cool thing: The "Mini-Split Heat Pump. Does both heat and cooling and takes a tiny amount of electricity for the heating (and cooling) it does. It's 200-600% more efficient than electric heaters. And you get "free" (well very cheap) A/C as part of the deal. Goodbye loud window units or dreadfully inefficient portables.

If that's too much for you, and you'd rather have electric heat, then since you're installing new circuits anyway, install baseboard heaters. For instance a 2000W Cadet heater is around $60 and is safe and legal to run unattended. It will also last 40 years, unlike those rinkydink space heaters that don't even last a season.

You can run a 2000W and 1750W Cadet heater on a single 20A circuit run with 12/2 cable - the very same stuff you're already planning to add to solve your problem. And now you have proper heaters - it can have an external thermostat so it's more reliable, it can even use "smart stats" like the Nest (though 24V thermostats will require addition of an "Aube style" relay).

However Cadets are just as costly to run as space heaters (in electricity)... and in a couple of seasons a mini-split will pay for itself in lower heating bills and be cheaper to run as A/C also.

The wiring was legal as done

I actually used a "professional". He's the one that was supposed to run separate wires and breakers for each room. He cut corners and just ran them all together. I had the space in the panel box and I bought 4 breakers so that he could do that. He only used 2 of the breakers...one for the laundry room and one for the hall, bathroom and bedroom and outside outlets.

The laundry room needs one 20A circuit that is dedicated to it.

The bathroom receptacles need to be on a dedicated 20A circuit that serves either a) only loads in that bathroom, or b) only receptacles in bathroom(s). Installer's choice.

Other than that, everything you listed is allowed to be on the same circuit per NEC. However, NEC is a slumlord "bare minimum" beneath which the house is unfit for human habitation. You can aim higher.

If your guy failed to provide the contractually required circuits then you need to go back and demand that. If it was verbal then that's not worth the paper it's written on. Setting your house on fire is not an appropriate response to contractor underperformance. It's also possible the guy is not a licensed electrician, and if so, they may have violated the law doing the work. I would have a talk with the inspector about that.

It's also possible your contractor brought in a sub who is a licensed electrician, and failed to pass on your written requirements, in which case that's between those two people and you're owed correct work.

If it were me, I would first ask - maybe they ran three separate home-runs and simply merged them onto the same breaker because you didn't have enough breaker spaces. If they ran a single home-run, I would segment that into 3 sections. Where sections 2 and 3 meet (2 choices of junction box here), I would run two 12/2 cables back to the panel (the cost is in the fishing; tossing in an extra cable costs very little). They'd feed sections 2 and 3, with section 2 being fed "from the wrong end" but that's fine.

  • Harp: I also thought of your suggestion of a mini-split. It's a lot more expensive up-front to install, but WAY cheaper to run long term. Electrical resistant heat needs to go the way of the dinosaur with the exception of spaces that are rarely used. My church has a lot of baseboard and other electrical resistance heaters, but most of those spaces are only used a few hours a week, while I'd like to see mini-splits installed, cost recovery would take a long time. It's controlled by programmable t-stats to ensure they aren't "left on" when not needed. Jan 6, 2023 at 17:23
  • Harp: hopefully not going to get snipped for getting conversational, but I literally did laugh out loud about the wiring on your "winter cottage" it reminded me of that old sitcom Green Acres and the wiring of their home. Eddie Albert and Eva Gabor. Come on man, I expected better of you! Just kidding of course! Happy New Year Jan 6, 2023 at 17:45

Breakers are by design and on purpose the 'weakest` part in electrical circuit.

If not so, the wires or the outlet will overheat, short and burn up before breaker can save them.

The fact that you are asking the question, alerts us to strongly advice you to always use a professional for any electrical work on your home.

Consequently if breaker trips it is doing its job, while a larger breaker will not trip and will not save your home from a electrical fire.

  • I actually used a "professional". He's the one that was supposed to run separate wires and breakers for each room. He cut corners and just ran them all together. I had the space in the panel box and I bought 4 breakers so that he could do that. He only used 2 of the breakers...one for the laundry room and one for the hall, bathroom and bedroom and outside outlets.
    – Chuck
    Jan 5, 2023 at 19:28
  • 1
    @Chuck nothing personal, but as you can see from other answers, you do not ask if you can replace 20A breaker with 30A breaker. However it is nobodies problem. The problem are the heaters. They usually need 'dedicated' circuit due to high power consumption. If you put two heaters on same circuit you will have the problem.
    – Traveler
    Jan 5, 2023 at 19:35
  • 2
    @Chuck btw I've never heard of someone having to buy their own breakers for the electrician. Normally he should get the breakers or at least tell you which ones to get because he knows the right ones to get (depending on your type of breaker box and the circuits he wants to put in). Same for the wiring, in fact he should have wiring in his truck because every house has the same few kinds of wiring.
    – user253751
    Jan 6, 2023 at 1:36
  • 3
    @Chuck it sounds like the electrician breached the contract by not doing what he was contracted to do. This comment brings a whole new light to the question, and you should probably jump over to Law (check what's on topic there first!) to ask about what recourse you may have. As you've figured out, your solution isn't what you think it is. I'm the last one to suggest "lawyer up", but it may be necessary in this case. Maybe just talk to the electrician first to see if you can get him to come back to do the right thing...
    – FreeMan
    Jan 6, 2023 at 14:04

You should replace your 20-amp breaker with 2 20-amp breakers. i.e. you need another circuit if you are going to be routinely running those heater loads.


As many people have mentioned, this is not the way to work with electrical. Breakers pop for a reason and that reason is to keep the load under control. If not they could result in fires.

The main point of the next steps is to have someone split them up into two circuits if you really need to use the two heaters at the same time. Simple as that. That's the only real safe viable option in this scenario.

  • Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.
    – Community Bot
    Jan 6, 2023 at 16:43

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