First off I know this is not the best idea.

To start my 200 Amp Main has suffered a partial failure and as it is old (60s) and unusual it will be very hard or impossible to replace it. Since the main breaker has failed only half of my breakers are working as only one of the hot lines from it is supplying power to the breaker box and so basically every other breaker is working.

This means of course that any double pole breakers will not work.

I need to wire up my water heater (18.8 Amp) using two 120V breakers.

Can anyone explain to me how to do this for a quick fix as my real fix will require a complete new breaker box and so on.

Main Breaker

  • 3
    Shirlock has it right - you cannot get 220v from two 110v breakers on the same leg of your box. You need one feed from each of your two incoming hot legs. You'll have to fix/replace the main breaker or replace the box.
    – JoeFish
    Dec 29, 2011 at 18:08
  • I would suggest if you must spend, use an inline tank , that is outside or on a roof, in plenty of sunlight. Use this tank to let the sun do half the work of heating the water during the day. For a small family you might only need this and a on demand heater. Also consider a solar panel water heater and well made holding tank. Mar 16, 2019 at 6:02

6 Answers 6


You cannot get 220VAC from one leg in your panel. You must have two isolated 120VAC legs to do this. Using two single pole breakers on one leg will still only give you 120VAC.

Why can't you have the main breaker replaced? You should be able to buy a replacement breaker without replacing the whole panel. Also, have you tried manually setting the magnets in the main breaker? This is done by removing it and slamming it hard down on all axis. This will sometimes physically reset the magnets in their proper position within the breaker and restore normal operation. They can sometimes be jarred out of position when tripped. But since you have to remove the breaker to do this trick, you might as well replace it with a fresh new one.

  • 1
    heinemann breakers are now made by Eaton, a common Canadian brand. You may have to take your panel model number to an electrical distributor that handles Eaton. I bet they can get you a replacement. I found them online easily Dec 29, 2011 at 19:10
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    @ian The electrician you call should be able to get the proper breaker. DO NOT DO THIS YOURSELF!. Replacing the main breaker requires you to shut power off to the whole house (either at the meter, or the pole), which will have to be done by either the utility company or a master electrician.
    – Tester101
    Dec 29, 2011 at 20:13
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    Should I really not do this? My electrical company has found me a UL listed Type CC 200 AMP breaker that matches meets code for my box and I have already scheduled the city to come and disconnect me at the meter. I know how to be safe with electricity and test for voltage before I start touching or changing anything.
    – ian
    Dec 30, 2011 at 0:31
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    OK, truthfully, swapping the breaker mechanically is not a big deal as long as the power is definatly OFF and the wires are going to fit exactly as they did before. Be absolutely sure the lugs are very tight and use a little Nolox on each one. Some states require a master electrician to do this task because it is critical that it be done right. Hopefully the utility will pull the meter, but in many areas they will just turn it in the meter enclosure and change the color of the tag. Be there and confirm with them that the power is off. Good Luck. Dec 30, 2011 at 6:59
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    Thanks for all the help I switched breaker a couple days ago without much fuss and its working perfectly!
    – ian
    Jan 6, 2012 at 0:54

Odd as it might sound, you could run the water heater on 120 volts. Based on the amperage you stated, it would be a common 4500 watt heater. At 120 volts instead of 240 volts (which as explain in previous answers you simply do not have), it will be effectively a 1125 watt heater (half the amps times half the volts). It will take up to 4 times as long to recover. Today's heaters are well insulated and should be able to reach a reasonable temperature even at the low wattage. You might add some extra insulation if the outside feels warm.

When I was in college, I moved into an apartment where the gas water heater was shut off and only had a lit pilot. I merely noticed it was taking a very long time to recover (nearly all day). But it was enough to shower once a day. I did this for 3 months before finding out that it was never running the main burner. Running the electrical elements on half voltage should be better than a pilot.

I'm also concerned about adding extra load to the remaining side of your panel. That could easily cause the crippled main breaker to completely fail. We don't know why it failed on one side. Why would that trouble not also exist on the other? This is something that needs fixed sooner, not later. These larger breakers are often similarly sized and a new one from another manufacturer may fit (have an electrician do that work). The connections in your photo are what is common in separate large breakers.

  • Thanks. If the water heater was running this way would Just one of the two heating elements be running. (they are 4500 watt) or would they both be running at lower power? Would letting the elements run so much longer damage them? I have been able to find a UL Listed replacement main breaker with the help of my electrical supply store. (my electrician could not and wanted to replace mine with a used one of the same model that he would maybe find online..)
    – ian
    Dec 30, 2011 at 0:35
  • They would both be running when you feed just 120 volts to the 2 conductors that power the heater. Some heaters MAY have an active control circuit that won't operate on 120 volts. Otherwise the two elements operate in parallel when the thermostat(s) indicate a need for more heat.
    – Skaperen
    Dec 31, 2011 at 2:40

Not an answer, @shirlock homes got the answer right. This is for the replacement breaker. Do a google search on UQFB200, a breaker made by Milbank. It has been around forever (early 60's?) and looks like your Heinemann. Forget about Cutler Hammer having it. Hopefully you can read the specs to compare measurement, but if you measure, keep your hands out of it and use nothing conductive!!!



  • Why do you say forget about Cutler Hammer? My electrical supply store listed this: yblighting.com/… as being suitable for my breaker box.
    – ian
    Dec 30, 2011 at 2:50
  • It was not a knock at C-H, just as getting a Heinemann replacement from C-H and I was going from your picture. If your local supply says that is the replacement, then they know what they are talking about, as probably you are not the only person in that area with that breaker and they have gone through all this before. Ask them if it is new and in the box before you get it. That's something that should always be asked when buying larger frame replacement breakers.
    – lqlarry
    Dec 30, 2011 at 5:59
  • @lqlarry; +vote on excellent research. Dec 30, 2011 at 12:12

I have used 120 volts to power a 240 volt hot water heater before. The 240 volt 4500 watt element will put out about 1125 watts of heat if hooked up to 120 volts. Depending on your hot water usage you might never run out of hot water. I had 3 people living in my home with a 240 volt hot water heater hooked up to 120 volts, and never ran out of hot water, but it was a 80 gallon HWH.

The hot water heater's recovery time, which is the time required to heat up the hot water used, will be about 4 times longer than if it were hooked up to 240 volts.

One could also replace the elements in the hot water heater with 120 volt elements. My local hardware store sells a 120 volt 1650 watt element for about $20. Use a 20 amp breaker. Replace both elements, upper and lower. Make sure you save the 240 volt elements to use when you solve your main breaker problem.


You could use a step-up transformer to increase the voltage (the opposite of what North Americans do when they go to Europe), however by the time you do this, you may as well just fix the actual problem. Residential main panels are inexpensive but there is a bit of labour involved to swap it out, and you usually need a licensed electrician do this work.

  • Even if someone would attempt this, I think it would be very hard to find the right transformer for the job. And the transformer itself is probably going to cost more than replacing the whole panel.
    – Vitaliy
    Dec 29, 2011 at 22:57
  • 1
    Even if you could find a transformer that big, you'd need a 50 amp circuit at 120 volts just to power the water heater.
    – Skaperen
    Dec 29, 2011 at 23:03
  • I know you are both right, but it is a possible solution and thats what this site is all about!
    – Steven
    Dec 29, 2011 at 23:17
  • Most water heaters are about 6 KVA, so you need either that size of transformer or half that size in boost mode. That's not prohibitive. Aug 5, 2017 at 22:01

Just wanted to note that when there are space issues at the breaker box, it may be worth biting the bullet and upgrading to a larger box... Or adding a subpanel, possibly even moving some of the existing circuits to that.

I did both, combined with upgrading my service from 100 to 200A. As long as I was considered a subpanel for the workshop and heat pump anyway, and had the electrician on site to hook up the heat pump, the additional cost was a good investment in future flexibility and ease of maintenance.

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