tankless water heater vs. small water heater.

[Spider]

Ok Ive been checking into these now and would like to have hot water for washing hands only. I have a few questions on them though.

Ive been looking at the PowerStream Ae12

under the sink, The ariston 4 gl under the sink and a GE 2.5 gallon water heater for under the sink. I understand the Ariston 4gl would have to be plugged into the wall full time so it can heat and keep the stored 4gl water hot. It has a

1500 element which sounds like its going to be pricey in my electric bill if left on all the time and if plugged in when only needed it'll take alot longer to heat the water and end up using a lot of electricity.

The powerstream ae12 appears to be the cheapest at $169.00 and sounds a bit pricey for hook up with 8 gauge wire and 2 breakers but for a one time cost of installation and the way I understood it to operate would be the better choice as the hot water is only heated when you turn on the water. When the water isnt on there is no electricity being used. Please correct me if I read it wrong. Also at 240v's how would I determine a size breaker I would need? Any formulas for this?

I just heard about the Ge 2.5 gl water heater but the guy at home depot said its better than the tankless.It'll use less electricity. To me it sounds similar to the ariston 4 gl as the ge has 1440 watts and plugs in as well.Not to mention it holds less water in the tank. So to my knowledge it would cost roughly the same in electricity use to keep the water warm just as the ariston.

It sounded to me that the smaller powerstream under the sink type tankless water heaters were more cost efficient in usage as it only uses electricity to warm the water when the hot water is in use. Is the powerstream ae12 giving you 12 gallons per hour? The units are priced near the $180 mark and under except for the aristone that was $129. Anyone know any different? Am I reading between the lines correctly?

[Robert Allison]

for under the sink,

gl

for under the sink and a

heater

> for under the sink.

The tankless water heaters only use electricity (except for a tiny amount) when you turn on the hot water faucet. The one with the tank will use electricity to keep its tank of water hot all of the time. So, if you put in GE 2.5, it will continuously keep the water hot. If you leave for 3 weeks, it will keep the water hot for you all 3 weeks.

The others will come on when you turn on the hot water and turn off when you turn off the water. So it will use no electricity for the 3 weeks you are gone. Or at night, or whenever you are not using water.

IOW, the tankless is much more efficient on electrical use.

The Ariston is just a water heater with a small tank so that you have hot water instantly. It is for use for areas that are far from the water heater and take a long time for the water from the hot water spigot to get to the fixture. It only has enough hot water to last until the hot water from the big water heater gets to the fixture. You will not be happy with this one.

With the Powerstream, you will never run out of hot water.

With the Ariston, you will run out of hot water in less than a minute.

With the tanked heater, you will run out of hot water in about

10 minutes.

YMMV, depending upon your water pressure, the size of your pipes, etc.

[Spider]

> for under the sink,

gl

> for under the sink and a

heater

> > for under the sink.

[hallerb]

If you live in a COLD area where incoming water can be as low as 40 degrees when it enters your home beware of the tankless,

just what are you trying to accomplish?

tankless have troubles when incoming water temp is low

tank types are pretty efficent well insulated the little heat they lose in the winter helps heat your home. you can add extra insulation to minimize those losses futher..

[Andy & Carol]

I heard that you have to have 200 amp service...I might have heard wrong, It was at a Home show which was noisy!

for under the sink,

gl

for under the sink and a

heater

> for under the sink.

[trucker]

> for under the sink,

gl

> for under the sink and a

heater

>> for under the sink.

If you live in the south (like Austin Texas) where the incoming water is

68 degrees F then tankless point of use water heaters make sense. If you live in Port Orchard, Wa. where the incoming water is 45 degrees, then you have to install a 200 amp or better electrical service to the house and run no less then 6 gage wire to the tankless heater to get decently hot water (110 degrees at one gallon per minute). Minimum of 12kw will be needed so: 12000/240 = 50 amps. The inspector will insist on 6 gage wire and 60 amp breaker. Oliver Sudden, your $200 water heater jumped up to about $500 bucks including the labor. And I know not what the power company will hit you for if they upgrade the service. The 4gl from Bosch can run on a 15 amp breaker and use Romex 2/14 just fine. But don't run yer toaster on the same line.

------------------------------------- Senate rules don't trump the Constitution. /\_/\ ((@v@)) ():::() VV-VV

[trader4]

It would seem that the first thing that needs to be clarified is what the intended application is beyond "washing hands". What is the incoming temp of the water in winter? How long will it typically be between usages? When it is used, will it usually be one or two people washing their hands, sepertated by an hour, at some remote location, or will it be 10 people in a row after a church event? And if there is some small probability of 10 people in a row using it on rare occasions, are you OK with the hot water running out? Unless someone has asked all those questions, then any specific recommendations are worthless.

As for reading the Powerstar datasheet specs, no it does not say that it will supply 12 gallons of water an hour. What it shows is how many gallons per minute the various models can supply with a certain temperature rise above the incoming water temperature. For example, the 7.2 unit can supply .75GPM with a temp rise of 63F. That would seem to be enough for one sink to be used for washing hands. If you run 1.0GPM through it, you can maintain a

48F temp rise. Even in cold climates, with incoming water at 40F in winter, that gives you water from 103 to 88F. Not hot enough for a shower, but could be fine for washing hands. And that unit only uses 30 amps, at 240V, so not too likely you're gonna have to change the service.

The tank type can be plugged into an outlet or wired into an existing

120V circuit, which is a plus. They can supply X gallons of water at 120F or whatever you choose, but only until it exhausts most of the tank. How well that works depends on whether you expect to wash two hands, or twenty. I wouldn't get too hung up on the cost of the electric to run it. The tank is small and reasonably well insulated. But that too depends on whether it's sitting in a house that's 70 or a shack that's 40. Certainly there are a lot of electric storage water heaters big enough to supply a house around, and while not as cost effective as gas, people aren't going broke from the standby losses.

Hopefully that will get you on the right track in terms of thinking this through.

[mkirsch1]

You do realize that you're responding to a FOUR YEAR OLD thread, right?

F U homeowner's hub.

[solhe]

I would never compare a small-tank water heater with a tankless water heate r. Mini-tanks are for point-of-use installations and they are meant to last until the main water heater kicks in. They are for giving you instant hot water and to alleviate the cold water delay that happens in outlets far fro m the main unit in very large houses. Mini-tanks just don't have power to r eplace the outgoing hot water in seconds as an electric tankless water heat er does. This article can give you and idea on what tankless is about:

eviews