Electric Hot Water Heater Repair

[bwottle]

Hi All,

I was wondering if someone can explain to me how a thermostat in an electric hot water heater works.

This is a Rheem hot water heater, it has two heating elements. I'm trying to determine of the thermostat is working right. I get 240 volts to the upper element, but at the lower element and at the terminals of the thermostat to the lower element I get zero voltage. I had assumed that they would both be on as long as the water needed heated?

I have just replaced both of the elements, one was bad as it had zero resistance, the other I just figured I'd replace. Since I now have the tank full of water again, I checked the voltage to the elements as described above. I'm not getting voltage to the lower element or the lower thermostat for that matter.

When the water in the tank is cold shouldn't I see voltage to both elements?

Thanks, Brian

[RBM]

Typically, one leg of the 240 volts, goes to one terminal of both the upper and lower elements. The second leg of the 240 volts goes to the upper thermostat. When the water is cold, it will send power to the upper element only. Once the upper thermostat is satisfied, it will disconnect power from the upper element, and send it to the lower thermostat, which in turn will send it to the lower element, until it's satisfied, or heavy water usage causes the upper thermostat to send power back to the upper element. Only one element will heat at a time.

[hallerb]

does any maker sell a dual heat at same time? with a 200 amp main both could probabl;y run at same time.

this would give a big capacity boost

[RBM]

does any maker sell a dual heat at same time? with a 200 amp main both could probabl;y run at same time.

this would give a big capacity boost

It would only require a 50 amp circuit, for typical 4500 watts X 2 elements. Yes, you can get commercial units with whatever wattage requirements you have

[John Grabowski]

does any maker sell a dual heat at same time? with a 200 amp main both could probabl;y run at same time.

this would give a big capacity boost

*Shouldn't you be worrying about basic survival needs now that the end is near. Hot water would only be a memory.

[WW]

John......SO your the guy I saw on the street last week with the sign saying "The End is NEAR" (g) ww

>

[bwottle]

Thanks for the explanation. It is working as you describe, so all should be well there.

The water temperature and the duration of the heated water all seem good now.

Thanks, Brian

[John Grabowski]

">>> > I was wondering if someone can explain to me how a thermostat in an

*Thanks for the thought WW, but I was being sarcastic in response to Bob's doomsday posting about the gulf oil spill. I think the end is coming, but we still have time to enjoy life.

[Stormin Mormon]

Of course, you could convert to an instant heater. Should help with the capacity boost.

[Stormin Mormon]

Buy more Bibles, and silver bullets?

[Stormin Mormon]

Guy standing at the side of a road, along a curve. Sign says "the end is near". Couple folks come along, at a rapid rate, and curse out the relgious whacko. They go flying around the curve at incredible speed, and then tumble into a ravine.

Guy at the side of the road says to himself, muttering "Wonder if I should have written instead.... 'BRIDGE OUT' ? "

[Stormin Mormon]

You people disappoint me. I havn't yet read the obligatory crack about "why do you have to heat hot water?"

After the GWB increase of freedom known as the Patriot Act (which means it's patriotic to remove most of the protections citizens have from government). And then the Obama Stimulus (which means that the economy gets better after the government spends money it doesn't have). Why would anyone think we're in trouble?

[Bob Villa]

I was told this once, by a plumber, "There is no need to heat "hot" water!". I said it before someone else!

bob

[Bob Villa]

There you go Mormie!

[Stormin Mormon]

You have restored my confidence in mankind. Excellent.

[hallerb]

yeah sure, convert to a electric tankless, dedicated 200 amp service JUST for heating water.

getting 2 new main panels, new service line from power company, perhaps a new transformer in neighborhood. and no hot watewr at all in a power failure. thanks I will pass on that!

besides I have gas water heater:) 75,000 BTU 50 gallon tank.

I only asked about this out of curosity, since family in phoenix have electric water heaters.

[The Daring Dufas]

I read a story about a guy driving through a rural area when he saw a sign that read "SLOW DOWN ROUGH ROAD AHEAD", he thought to himself, I have good tires and shocks what's to worry about. Suddenly, he hit a patch of road best described as the washboard from hell, when the road smoothed out he saw another sign that read "SEE".

TDD

[Stormin Mormon]

The one time I got asked to help install an electric instant. It was 240 volts, 30 amps. I'm not sure what was the rate of rise, but who knows. 30 amps is still useful.

This one lists whole-house capacity at 80 amps.