Will A Point of Use Water Heater Work For Me? (washer, hot water heater)

[nightwishfan]

I've been reading up on "tankless" point of use and whole house water heaters, and I have a question for people in the know (I haven't found my answer by googling it).

The point of use heaters are much less expensive than the whole house ones, I'm talking about electric here, not gas. I've seen them for $200 and less, this is something I could afford.

All of my hot water using items are within about 10 feet of each other. The bathroom shares a wall with the washing machine (don't use hot water much, but once in awhile will use warm wash) which is in the kitchen, the sink is across the kitchen maybe 6 ft away or so.

So the question is, since all my hot water using things are so close, could I get away with using one point of use water heater, if I only use one hot water item at a time?

Also many of the smaller point of use heaters plug in rather than being hardwired, this is a plus to me. However I don't know whether they plug into a regular plug, or whether they need a plug similar to an electric dryer.

Thanks for your input!

I forgot to mention that my current hot water heater (which isn't currently hooked up to a fuel source) is located on the other side of the bathroom wall, so if a point of use was installed in the same area as current one, hot water would run more like 15/20 feet. It would go heater, bathtub, bathroom sink, washing machine, kitchen sink. Though if it's not a matter of changing pipes around a ton, I could install it in the bathroom or kitchen too.

[derekv]

I have a Tanita tankless and it is awesome. It is gas and externally mounted, but in TX that isn't too much of an issue. The point of use heaters I have seen won't cut it for anything other than making tea or hot chocolate. They produce something like .5 gpm. If you end up going tankless, makes sure the installer gets the venting correct. Most of the tankless need a larger diameter duct than your current water heater.

[derekv]

whoops, it isn't tanita (they make bath scales), it is a Noritz

[Donn2390]

.Tankless heaters are super, but all of my research shows it's best used for new construction. it's too expensive to retro fit into an existing home. It cost as much or more to install as it does to purchase, so the price climbs in a hurry. You will spend at least a couple a grand, and possibly twice that.
The solution I came up with is to get a hot water re circulator. Mine is mounted under the sink in the farthermost bathroom. It's simple 2 minute hook up. You can let it run constantly, or put it on a time for the times of day you want hot water. Even if you let in run all the time,it has a sensor, so it shuts off when water reaches a preset temperature. I use a remote switch for mine. When I want to shower, I flip a switch, and by the time I'm ready to jump in the shower, the water is hot. No more letting the water run for five minutes, hoping it will get hot. That costs you water and natural gas.
Obviously it needs a H/W heater to operate, so if you are trying to eliminate the heater, this won't work. The point of use heater you are talking about wouldn't supply enough hot water to do anything. They are designed to supply hot water until the hot from the main heater reaches you.

[studedude]

You need to check the temp rise on any tankless water heater you consider. One model I use to sell had a 27F temp rise at 3 gpm. If your water gets down to 50 F in the winter you would be washing clothes at 77 F. A shower, reduced to 2 gpm would be taken with 90 F water. Warm but not a hot shower. Just remember temp rise=$. They are nice but do your research.

[nightwishfan]

thanks for the input. So it sounds like i'd need to go with a electric whole house tankless.

[nightbird47]

Originally Posted by nightwishfan

thanks for the input. So it sounds like i'd need to go with a electric whole house tankless.

I was planning to go with that in my new place since the gas type take very expensive venting. But having read up on it I'm not sure its such a great savings.

Make sure you read up on the voltage requirments for the setup as they are higher than the standard and the degree of heating based on the outside temp. I've seen a lot of conflicting ideas about it and have decided to go with a small regular water heater instead since I can't sort through it too well.

[fpbear]

A lot of the responses confused the original question (small point of use electric heater) with the gas or electric tankless water heaters. These are very different. The gas tankless water heaters are wonderful (I have a Rinnai). To answer the original question:

I also have a Stiebel-Eltron (great quality, Made in Germany) point of use mini heater under the kitchen sink. It works great so that it can supply instant hot water ahead of the main heater, since the water cools off in the long pipe runs. The problem you would run into trying to use it for the whole house is that these only have a small reservoir - about 1 to 8 gallons. So if your washing machine uses some of the hot water, then it may run out and you have to take a cold shower after that. It takes a while for these to heat up, these point of use electric models are not instant. The electric instant ones are more expensive and need dedicated high amperage circuits, and result in big electric bills. The best ones for you I think is some kind of gas model, either one with a large tank, or a gas instant heater if your gas pipe is big enough.

[Brian_M]

RE: point of use and whole house when talking tankless, the ONLY difference is capacity. Meaning temp rise per GPM. The point of use units have less as they are intended for one output only while the whole house units can usually support 2 or 3 (in colder climates like WY and MT).

I have experience with gas and electric whole house as well as electric point of use. So long as you size them correctly a point of use Can easily serve a whole house. We have exactly that setup in a ski cabin in Montana. One small tankless unit, electric, that feeds the shower and both sinks (no washing machine or dishwasher). Very usable with only one thing drawing hot, absolutely can not do 2 things at once. It's been trouble-free for about a decade now, even with iron-laden well water.

I'll be using the same thing with a new shop building (shower and 3 sinks) as they are simply cheaper to buy and operate for "part time" use.

[AlaskaErik]

My new house in ALaska has a gas tankless. So far it's worked just fine. As others have mentioned, you need to know the temperature of the water as it enters the unit. Our water temperature is in the 30's, so it requires quite the rise.