converting a water heater to 240v

[trainer]

I've got a 12 gallon 120v water heater in my garage. It works ok, but is a bit slow recovering. It's got a single 1500watt element.
Does anybody know if I can convert it to 240v and put in a 3000w element? would I need to replace the high limit and thermostat also?

Here's the manual for my heater.
http://www.gsw-wh.com/pdfs/products/water/spacesaver/61515-1K.PDF

 

[nissan_crawler]

Sounds like a waste of time to me. Buy what you need, have it new, sell the old for what you can, move on.

 

[Charles (in GA)]

Most water heaters, even small ones like this are offered with different elements. Do a little research to see what was originally offered. I would think you need do nothing more than change the element and remark the data plate. Thermostat and high limit switches will be carrying the same amperage (1500 watts at 120V is the same amps as 3000 watts at 240V) so those should not need changing.

Charles

 

[nissan_crawler]

The question to me would be how old is it?

 

[ddawg16]

This might be a good time to consider tankless. The garage is actually a perfect application for one. It's only on when you are using hot water....which in most cases is once or twice a day. And they take up a lot less space.

Unless you mean the heater for the house is in the garage.....

Still....everyone that says they have a tankless swear by them.

 

[rinny_tin_tin]

I've got a 12 gallon 120v water heater in my garage. It works ok, but is a bit slow recovering. It's got a single 1500watt element.
Does anybody know if I can convert it to 240v and put in a 3000w element? would I need to replace the high limit and thermostat also?

Here's the manual for my heater.
http://www.gsw-wh.com/pdfs/products/water/spacesaver/61515-1K.PDF

Figure 1 of your manual shows that you could wire it for 240. The 3K element question you will need to ask of the man

 

[trainer]

The question to me would be how old is it?

The tank is only 6 months old. A 3000 w element would probably be $20+\- and I already have a double pole 20a breaker. Since the amerage is the same on 120 or 240, there should be no need to run a new wire.

A tankless would be nice, but right now $20 sounds better than $500+ and the heavy wiring associated with one.

 

[BigChevy80]

The tank is only 6 months old. A 3000 w element would probably be $20+\- and I already have a double pole 20a breaker. Since the amerage is the same on 120 or 240, there should be no need to run a new wire.

A tankless would be nice, but right now $20 sounds better than $500+ and the heavy wiring associated with one.

That's the same predicament I am in. Our water heater is original with the house (built in '92) and will probably need replacement soon. I still can't justify the $1100 price tag when a regular tank heater is only 1/4 that price.

If it's an option for you, you might want to consider a gas fired heater. An electric water heater is one of the most inefficient appliances on the planet. Of course, if you don't have gas service then that's not an option.

 

[trainer]

I've got a natural gas heater only 15' away, but here all the installations here need to be done by a licenced contractor.
Those guys aren't cheap or prompt here. So, I'd still be looking at $500+ and probably have to wait for months.

 

[VHF]

You might not even need to change the element... an element would need to have the same resistance to deliver 3000W @ 240V as to deliver 1500W @ 120V. On the other hand, it is possible there is still some difference in the 1500W 120V element. Might be worth calling the tech support # at the end of your manual and consulting with them about converting to 240V.

 

[jwith68]

You might not even need to change the element... an element would need to have the same resistance to deliver 3000W @ 240V as to deliver 1500W @ 120V.

NO! Ohm's Law states that power equals voltage squared divided by resistance.
http://www.the12volt.com/ohm/ohmslaw.asp#pie
So, doubling voltage across the same resistance will quadruple power. That will (at the least) destroy the element in a very short time. The 3000W, 240V element will have to have double the resistance of the 1500W, 120V element.

Might be worth calling the tech support # at the end of your manual and consulting with them about converting to 240V.

Yes!

 

[Charles (in GA)]

If it's an option for you, you might want to consider a gas fired heater. An electric water heater is one of the most inefficient appliances on the planet.

I don't consider that a fair statement. With electricity, there is no waste, no heat or exhaust up a stack, it ALL goes into creating heat for the water. I highly suspect that a electric water heater is much more energy efficient than a gas one. That being said, gas heats up much faster, and might be more cost efficient, as I suspect that a BTU of electric heat is probably more costly than a BTU of gas heat.

I grew up with a gas water heater, and when I bought this total electric house, I was dreading it, but I have been quite surprised at the efficiency of the heat pump and the water heater, and the "quickness" of the water heater to recover.

Charles

 

[rinny_tin_tin]

I don't consider that a fair statement. With electricity, there is no waste, no heat or exhaust up a stack, it ALL goes into creating heat for the water. I highly suspect that a electric water heater is much more energy efficient than a gas one. That being said, gas heats up much faster, and might be more cost efficient, as I suspect that a BTU of electric heat is probably more costly than a BTU of gas heat.

I grew up with a gas water heater, and when I bought this total electric house, I was dreading it, but I have been quite surprised at the efficiency of the heat pump and the water heater, and the "quickness" of the water heater to recover.

Charles

Charles is correct - electric heating is the most efficient and cheapest. Almost all the electric energy is converted into heat, and especially so when heating a fluid.

 

[ddawg16]

Charles is correct - electric heating is the most efficient and cheapest. Almost all the electric energy is converted into heat, and especially so when heating a fluid.

And that is not a totally correct statement either.

Yes, Electric is more effecient at heating water. Almost all of the energy sent into the water heater is used to heat the water.

However, on 'average', for the same BTU's, gas is about half the cost. So, unless the user lives in an area where electicity is real cheap....in most cases a gas water heater will be cheaper to operate than an electric one.