Looking to buy a kenmore 20 gallon water heater.110 has 2000 watt element 220 has 4000 element.I was told either way they will use the same amount of electric just the 220 will heat up more quick .Is this the case.I ask because sister said she had a 110 dryer once and electric went through the roof.Also the 30 gallon and larger water heaters have the yellow label giving you the yearly cost at a set KWH rate along with the energy factor.now on the sears site they don't even have this info for the 20 gallon but it does have the same insulation R value and that being 16 so could I assume the energy factor is about the same.

Unless you have a teenager that stays in the shower until the hot water runs out, it may not make much difference. It that case, the larger element would allow a few more minutes. It needs to be on its own circuit, and 12-2 will be fine for either.

220 is more efficient for the most part. One major factor is single or duel elements. Duel elements are much better at maintaining temperature.

When the voltages doubles from 120 volts to 240 volts the aperage is cut in half and it is the amperage that determines the cost of electricity. But the work done also doubles so the cost would be the same. However 240 does a better job because of the recovery time it takes to re-heat the water replaced as it is used. A 240 duel element heater usually has an element at the upper that is 4000 watts and the lower will usually be 4500 watts. The upper element is hardly ever used until you have used all the hot water in the lower half of the heater. And only one element works at a time, both elements are never on at the same time. So you may consider the cost of wiring the 240 volt heater in making your decesion.

Well according to my power company they say to see what it cost to run the heater use this formula. Take the watts x the hours run a month divide by a 1000 to get killowatt hours then x the KWH cost.Many people have said it's the amps but I have read numerous sites where it says convert the amps to watts then x the hours used and divide by a 1000 just like the power company says.I've decided though I will go 220 30 gallon with a 12 year warranty whirlpool brand.Anyone here have input on whirlpool water heaters good or bad.Thank you

If you look at your electric bill, you are charged for kilowatt hours. That is 1000 watts for an hour. Watts are amps times volts. So the formula the electric company is correct. Don't know how you would come up with a good number for how many hours the water heater would need to run.

You might post to the plumbing forum and ask if it is as important to flush an electric heater as it is a gas one. I regularly drain water out of the bottom of my gas heater. It is an off brand one I got cheap 25 years ago, and it is still doing fine.

Well regardless if gas or electric draining and getting sediment out will help.Keeping things clean so the element doesn't become buried in sediment will only help keep it efecient.The power company web site uses 90 hours a month that a water heater runs.Who knows though maybe this is drawing a glass a day and not realistic.I do think they are basing things on family of 4 but not really sure.Yes 220 heat water back up more quick but if its just me and all the hot water I use a day is a shower does it really matter how quick it heats it.I mean is 110 20 gallon going to kill me no by the nest day I would have hot water to shower once again.If I go 220 I'm going 30 gallon whirlpool from Lowe's.Yeah 220 has bigger elements so heat more quick but also talking twice the water.Comparing apples to oranges.My points are A I don't like the idea of keeping 30 or 40 galons of water hot when I might use 15-20 a day for shower. B If electric bill going to be say 50 a month for 220 and was even that for 110 I would be cool with that. C Not rockafella here so if I go 110 and get $150.00 bill for hot water and say oops well for time being I'm stuck with it.Yeah 220 get me back in the hot water faster but overall keeping small amount of hot water hot I think plays more into me wanting to keep things on the cheap.See first like I said I eat outside the home so no dishes to wash and clothes are done at laundry mat so shower is it and I want the way that for my needs will give me the lowest possible electric bill.Maybe I want the best of both worlds not really sure.

In regard to the first part of your question. It is the rating of an element in watts (you mention 2000 watts @110v vs. 4000 watts @220v-not apples to apples) that will make recovery faster... not the voltage. The voltage will determine how many amps are pulled to do the same job. Example: a 2000 watt element will pull less amps @220v than a 2000 watt element @110v, but both applications will heat the water at the same rate. If you have a choice go with 220v (110v hw tanks are made in case higher voltage is not readily available). Using 220v power in a hot water tank is less expensive because lower amp draw means less resistance and therefore cheaper to run... He bows... thankya vera much!

What no one has said is that in 220V heaters there are 2 elements that turn on alternatly to keep the different zones (top and bottom) of the tank hot, so it is running twice as much. A small 20 gallon heater only has one element that runs off 110-120v. My average bill with a 220v heater was $35 to $45 a month. I just reacently got a 20 gallon 110v tank and have yet to get my first bill but through lots of research and calculations I estmate the cost at about $15 to $25 a month. The power company told me it would be about $12 to $17 a month but who can believe the power company. Also I like to take long showers and have no problem with water running out (with low flow high pressure shower head).

This old house. Great answer to a question that was asked in 2005 and then hit again in 2007!

I am faced with the same delema. I am building a small utility building on property on Texas Gulf Coast. Within this building I want to put a small shower stall with a hot water heater to supply this shower and occasionally use a washer. It will be for vacation/weekend use and most of the time there will be only 2 to three adults(short shower time). The price difference between a 20 gal and 30/38 gallon electric is minimal. I plan on putting it on a heavy duty platform so a electric dryer can sit under for space saving. I've been told we will want to leave it on even when we aren't there to keep the stale water smell and bacteria down. After reading posts I'm still uncertain which to use. Any suggestions would be appreciated