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Old 10-15-2008, 06:21 PM   #16
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Why do water heaters have two elements?


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Originally Posted by gp_wa View Post
The point about faster recovery doesn't make any sense. 4500 watts puts 15000+ BTU into the tank no matter where it is.

Are you really going to disect this? It works, does it not? Why not go out and buy a electric water heater and disable one of the elements and see what happens.

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Old 10-15-2008, 06:32 PM   #17
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Why do water heaters have two elements?


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Originally Posted by chris75 View Post
Are you really going to disect this?
Of course

Quote:
Originally Posted by chris75 View Post
It works, does it not? Why not go out and buy a electric water heater and disable one of the elements and see what happens.
I have, essentially. If your upper element goes out you won't ever notice. Been there done that.
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Old 10-15-2008, 06:41 PM   #18
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Why do water heaters have two elements?


Quote:
The point about faster recovery doesn't make any sense. 4500 watts puts 15000+ BTU into the tank no matter where it is.
I think he meant that the 20 (or however many) gallons at the top of the tank would recover faster, not the whole 50 gallons. From an end-use POV you'd get hot water back faster after depleting the tank, just not a full 50 gal. at your disposal.
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Old 10-15-2008, 07:23 PM   #19
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Why do water heaters have two elements?


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Originally Posted by gp_wa View Post
Of course

I have, essentially. If your upper element goes out you won't ever notice. Been there done that.
IMO, you would notice.
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Old 10-15-2008, 09:53 PM   #20
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Why do water heaters have two elements?


Quote:
Originally Posted by gp_wa View Post
Of course

I have, essentially. If your upper element goes out you won't ever notice. Been there done that.
as a matter of fact, in most water heaters you would most definately notice a difference. You would have NO hot water. The upper t-stat is designed (like I said, in most water heaters) so that it will not allow the lower element to be energized until the upper t-stat is satisfied. Since the upper t-stat would never be satisfied, it would never turn off the upper element and allow the lower element to be energized.

therefore, no hot water at all.

and yes, Scott R is correct on the faster recovery.
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Old 02-08-2012, 06:44 PM   #21
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Why do water heaters have two elements?


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Originally Posted by gp_wa View Post
The point about faster recovery doesn't make any sense. 4500 watts puts 15000+ BTU into the tank no matter where it is.
Because, since there is no disruption of the stratification layer, the top element and thermostat are off (top portion of water heater is hot). Bottom of the water heater see's the cold water that is coming into the tank. Bottom thermostat see's the cold water, and turns on, to heat the bottom incoming water. Top element doesn't need to be on because already has hot water. Sounds good anyway!
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Old 02-09-2012, 02:56 PM   #22
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Why do water heaters have two elements?


Re: convection: Cold water is denser than hot so it stays lower in the tank, reducing convection effect (in theory at least)

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