240V electric water heater on 120v circuit

heater

USe it as it is now set up. There is no fire danger. If the circuit breaker starts tripping, then have a plumber install small wattage elements. That is how Sears and others make their heaters "energy efficient".

Listen to these electrical pros. (I'm not one, just a long-time DIYer and a 20+year NC real estate broker.)
You may get by with what you have now, but you most definitely WILL have a problem when you or your heirs sell this house (with a buyer's licensed General Home Inspection or licensed Electrical inspection).
GHI's are usually very thorough around here, especially on the electrical systems, and they would promptly flag this as a "code violation and safety hazard", which a buyer (and their lender if they're made aware of it too) would require that this be re-wired to code, most likely at seller expense.
A seller may legally refuse to do any corrections, but that gives the buyer a free "get out of the contract with my earnest money back" walk, if you don't.
Also, if you ever have a house fire due to this circuit, guess who's insurance can refuse to pay any damages whatsoever?
If it were me, I would have this done properly, perferably by another electrician. Your call. "Pay me now, or pay me more later".
Good luck!
Mike

Yeah, but in today's world of home inspectors they'll surely demand YOU pay for it.

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Of course.

Like Mike said, "pay me now or pay me later".

Stated another way: a 30 amp circuit can supply a single appliance at a maximum of 80% times the rating. 30 x 80% = 24 amps
20 x 80% = 16 amps So #12 will not work for a 18.75 amp load.

I think this applies to any single appliance, continuous load or not.

ked said:

Stated another way: a 30 amp circuit can supply a single appliance at a maximum of 80% times the rating. 30 x 80% = 24 amps
20 x 80% = 16 amps So #12 will not work for a 18.75 amp load.

I think this applies to any single appliance, continuous load or not.

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Why 80% twice?????????????????????????????????????????

ked said:

Stated another way: a 30 amp circuit can supply a single appliance at a maximum of 80% times the rating. 30 x 80% = 24 amps
20 x 80% = 16 amps So #12 will not work for a 18.75 amp load.

I think this applies to any single appliance, continuous load or not.

Click to expand...

The only reason that the water heater can't be served by a 20 Amp circuit is the explicit code restriction that apply:

422.13 Storage Type Water Heaters. A fixed storage-type water heater that has a capacity of 450 L (120 gal) or less shall be considered a continuous load.

AND the additional code requirement that says:

422.10(A) . . . "The branch circuit rating for an appliance that is continuously loaded, other than a motor operated appliance, shall be not less than 125% of the marked rating, . . .

The circuit will work fine but 422.13 and 422.10 make it non-compliant with the code.

Everything finally fixed

I have to say it again, I have never found a more responsive or helpful board on the Internet. You guys are great. I will definitely be tuning in and even chipping in my opinions if I think I can help anybody else like you have helped me.

So, I have good news about my installation. I got my local building inspector to come and look at the setup and they concured with all of you. I also called the estimator for the company that did the work and told me that he would not recommend that setup. I went to the owner of the company and told him both of those facts. Not only did he state that he woudl resolve the issue, but he did so without charging me any additional money. So I have a 30A breaker and 10 gauge wire tip-to-tip. I feel a lot better about it.

Again, thank you all so very much for your input. I learned a lot, and am very glad that I visited this site!!!