Using a heater and a toaster oven together, both about 1500w each, trips the breaker. It seems both are on the same circuit. Moving either appliance to a different location is not really an option. Can an electrician do something so that this load can be handled? I want to get an idea of his work.. what will he do?

  • 13
    This could use a location tag, since all of the answers seem to assume North America (120V)
    – Mars
    Dec 18 '19 at 7:29
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    What country are you in? This is important information. Everyone is assuming you live in North America. Is this the case?
    – J...
    Dec 18 '19 at 15:23
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    Pictures on older questions indicate he is in the US. That and 1500w is the typical max heater size sold in the US. In fact almost all space heaters sold are 1500w because of our typical 15A@120v circuits (15 * 120 * 80% ~= 1500).
    – JPhi1618
    Dec 18 '19 at 17:24
  • Well the op said they wanted both heat and toaster oven, but I guess it accepted an answer to not turn them on at the same time makes me think the question was a joke!
    – Ed Beal
    Dec 19 '19 at 1:00
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    @EdBeal Most people don't know it is a valid solution... The alternative is 1) do something stupid and burn your house down 2) hire an electrician, and spend thousands or even tens of thousands to re-wire your house. This involves ripping out the wires out of the walls and putting in higher gauge wires. Most people don't know the circuit breaker is to prevent your house from burning down.
    – Nelson
    Dec 19 '19 at 1:46

There is something you can do: Do not turn on both appliances at the same time!

This is relatively straightforward for the combination of a heater and toaster. Unless you are a toast making factory, the toaster runs like 3 minutes per day. During that time, turn off the heater.

  • 3
    Not a terrible solution on a budget, but it does say "toaster oven", so it could be running for much longer than a sliced toast maker.
    – JPhi1618
    Dec 17 '19 at 20:07
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    @JPhi1618: Oops! I overlooked the toaster oven part. Perhaps the answer isn't as useful as intended.
    – wallyk
    Dec 17 '19 at 20:09
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    We'll just say that it might help someone else in a similar situation ;)
    – JPhi1618
    Dec 17 '19 at 20:09
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    ...but if operating in oven mode, it throws heat, so still a perfectly good answer, IMHO.
    – Ecnerwal
    Dec 17 '19 at 20:36
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    Actually it's much simpler than doing what seems to be a costly job. Will turn off the heater. It's just a matter of remembering to do it every time. Dec 18 '19 at 23:50

Yes an electrician can fix this. I would suggest a second 20a circuit be pulled in. Since you said toaster oven (in a kitchen) there should be 2 20 amp circuits for the small appliances already. 3000w / 120v= 25 amps so you really don’t have many options as you are limited to 20 amp circuits. Depending on the type of service panel and if it has space may really affect the cost ( and access to an attic or crawl space to pull the new circuit). You should be able to get a quote on the job that explains the scope of work , new circuit, number of boxes and outlets ect.

  • 3
    And permits, if your jurisdiction requires them.
    – WBT
    Dec 19 '19 at 15:39
  • Most importantly from a safety perspective, you have to have wiring that supports higher amperage for that circuit. You cannot just put a higher amperage circuit breaker in and call it good unless the wiring is a low enough gauge.
    – Mark
    Dec 20 '19 at 17:09

Why run the heater if the toaster oven is on?

When the toaster oven is on, it also is putting 1500W of heat (about 4000 BTU) into the room. Therefore it is redundant to the heater, and you don't need the heater at those times. You can turn it off.

Someone raised an issue about toaster oven heat being delayed heat. Since your other heater is a radiator type, it is also delayed about the same. So shutting off the heater while toasting is a good plan that will yield about the same heat in the room.

Improving service means running new cables to the service panel.

The electrician will cheerfully take your money to run 1 circuit on 1 cable.

However, the lion's share of cost will be labor of fishing cables through the walls. That labor is unaffected by whether 1 cable is run, or 4. So there's big economical savings in running as many as 4 additional circuits on 4 cables (provided you have the circuit breaker space) for barely more than the cost of cables and outlets.

There is also a way to run 2 circuits per cable, however it is largely obsolete and requires compromises.

If this is a kitchen, there is no such thing as too many circuits in a kitchen. Code now requires 2 complete 20A circuits merely for kitchen countertop receptacles. Practicality calls for a dedicated non-GFCI circuit for the fridge. You can't have too many.

Think about a circuit dedicated to heating

If you're running a new circuit anyway, you'll get far more heat capacity by running a 240V circuit. This allows up to 3840 watts of heating per circuit instead of 1500. Further, it allows (requires) you to use installed heaters actually made for, and safe for, permanent/continuous service. Cost for the heaters is very minimal, at $50 for a 2000W Cadet, and that's comparable to a radiator style heater and cheaper-by-the-year than those cheapie 1500W heater-fans. And worlds safer!

And you can run two of them on a 20A/240V circuit. Resistive heating is cheap. To buy.

  • 6
    When the toaster oven is on, it also is putting 1500W of heat ... into the room. Not really. When the element is on that's true, but the element is likely to be switched by a thermostat. Once it's warmed up it probably only averages something like 1/10 of that, which may not be enough to keep the room warm. So you turn the heater on, then when the thermostat on the oven comes back on, the breaker trips.
    – Chris H
    Dec 18 '19 at 9:04
  • That's not even true when the element is on. Any decent oven would be insulated so the majority of the heat is kept in the oven. In order for an oven to heat the room one has to run it with its door open.
    – n0rd
    Dec 18 '19 at 22:14
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    @n0rd No, the heat still ends up in the room; insulation just puts a time delay on it. Not that much of one either. So if you ran it from 1:00 to 2:00, the full 1500 watt-hours would indeed end in the room, just from 1:15 to 2:15. Dec 18 '19 at 22:19
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    @Tony_Henrich The radiator/oil heaters are safer than cheapie heater-fans, but still not as safe as properly installed heaters like a Cadet. Also, radiator/oil heaters have about as much thermal delay or inertia as a toaster oven; rendering n0rd's point above entirely moot. When both are running, you are putting 3000W of heat into the room. Do you really need that? Dec 18 '19 at 23:54
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    @harper Your answers are full of how things operate. My question is NOT why the breaker trips. My question is about finding a solution. For heaven's sake, stop asking why I am using a toaster oven to heat a room. I am not. I am heating FOOD for a few minutes. I bought a radiator heater. I am using it because I bought it and I like it. I don't care if a cadet is better more efficient or whatever. You're comments go into different directions. Anyways, I already accepted an answer. Dec 20 '19 at 0:53

Kitchen circuits have been required to be 20A for a long time, your capacity then is 120 Volts x 20 Amps = 2400 Watts. If you reduce the heater to 900 or 600 watts then it should not trip. If it does then your breaker is likely failing and replacing it may help. However you may actually find more devices on the same circuit, even the fridge is allowed to be on the same circuit as countertop receptacles.

Sometimes people state that a circuit should not be loaded more than 80%, this is generally conservative and safe advice, but the NEC only restricts 80% on motors and circuits that operate at full current for 3 hours or longer, which both the toaster and heater should be cycling loads.

Otherwise routing another cable or two from the panel is the only option, this could take 2 hours, it could take 22.

Bear in mind your general purpose receptacle circuits were not designed to replace an engineered heating system. Constantly using general purpose in that manner will certainly result in shortened lifespan of some of electrical system components.

  • 1
    Just want to point out that while you're right and the portable space-heater types are not considered continuous load, a fixed heater (like electric baseboard heaters) is.
    – DrewJordan
    Dec 18 '19 at 17:21

The only thing that can be done will involve running a new wire, which is typically a more expensive job (compared to just switching out some light switches or an outlet). There might be a shortcut that can be taken depending on how nearby circuits are run, but figuring that out would take an on-site electrician anyway.

Go into the bid process assuming that a new wire will need to be run. If there are not any blank spots in your current breaker panel, that will make the job a little more expensive if you can use "double" breakers, or a lot more expensive if you need a second electrical panel.

What you can't do is just replace the breaker, because the breaker is limited by the wire size. Even if you happened to have wire rated for a 20A circuit, that still is not enough to power two 1500w appliances.


I had a similar problem with a toaster and microwave. The breaker was old (circa 1975). I replaced it. Problem solved.

  • What make and model was the old breaker, and what did you replace it with? Dec 19 '19 at 0:09
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    That's poor advice. Two 1500W devices means 3000W total. If this is in North America, 3000W/120V means 25A, and the circuits are limited to 20A. While it's possible that a new breaker could help in specific scenarios, you should at least explain that, especially since it likely won't help in this case.
    – Bort
    Dec 19 '19 at 17:06
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    Toaster and toaster oven are two different problems. A toaster oven runs for longer time. Thermal magnetic breakers trip based on an inverse time curve. NEMA standards have a trip window that by spec should not trip for 90 seconds at 125% overload. After that you are in a trip window, the longer it remains overloaded the more likely it will trip. Dec 20 '19 at 4:43
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    One benefit to the implied (rather than stated) approach of putting in a breaker that's rated too high for the wiring is: The wires in the wall will soon help in warming the room, as well.
    – Ghedipunk
    Dec 20 '19 at 21:39
  • This is certainly better reading than the comment threads on this page. It's not going to solve the OP's problem but a crappy old breaker will exacerbate similar situations. All the other answers here are obvious to the contractor in me; not of-the-mind of a repairman like this one is.
    – Mazura
    Dec 21 '19 at 3:38

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