"Point of Use" or "Whole House Tankless"?

[Arby]

I'm building a new home. It's a small one bedroom, one bath. 900 square feet. As such, space is at a premium. So, the conventional big tank heater is out. We don't have gas, so it is electric....and either one Whole House Tankless or three Point of Use heaters....one in the kitchen, one in the bath, and one in the laundry. The washer is only 12' from where the heater would be in the bathroom so......maybe we don't need that third heater for the laundry. ???

At any rate, the budget is a consideration. That said, I'm not keen on running water, waiting for it to get hot...but that's not a deal breaker if it means saving a big chunk of change.

If it helps/matters, the longest spread between the plumbing is 32'. So...there's my kitchen, then the bath 20' from there, and the laundry washer another 12'.

So........what would you all recommend in my case....2 or 3 Point of Use heaters.......OR, one Whole House tankless in the bathroom?

 

[Twowaxhack]

I would go with a 30 gal electric. Sure it takes up a little room but it’s service friendly and they’re cheap.

If I did an electric tankless, which I wouldn’t most likely, I’d only use 1...not point of use at each fixture. Initial cost and maintenance too high iMO.

 

[Twowaxhack]

If I did go with electric tankless it would be a Stiebel Eltron and depending on your average cold water temp and expected demand would help me size it.

 

[Arby]

I would go with a 30 gal electric. Sure it takes up a little room but it’s service friendly and they’re cheap.

If I did an electric tankless, which I wouldn’t most likely, I’d only use 1...not point of use at each fixture. Initial cost and maintenance too high iMO.

Roughly speaking, how much more initial cost? And would it be offset by the longevity of the tankless heaters? Lastly, what maintenance is there on the tankless?

Thanks.

 

[Twowaxhack]

Roughly speaking, how much more initial cost? And would it be offset by the longevity of the tankless heaters? Lastly, what maintenance is there on the tankless?

Thanks.

We could speculate and throw numbers around all day.

If cost is even is remote factor then get a tank. If you have plenty of money for possible maintenance and initial purchase, go tankless.

If you didn’t have any maintenance cost or problems then you might be better off with one larger tankless.

If you had one problem that you have to pay for with a tankless then you’re screwed because it’s probably going to take two service trips plus parts at the very least. That’s $300 labor from my company plus parts, and that’s minimum......

It can get expensive, really quick.

 

[Twowaxhack]

Where are you located and what’s your incoming water temp ?

 

[Arby]

Where are you located and what’s your incoming water temp ?

Thanks. I'm in South Central Idaho. Water temps are generally, if I'm not mistaken, in the high 50s around here.

 

[JG plumbing]

I have a tank heater from 1985 (glass lined) . Lots of them last 20 years (water quality /type is a major factor). In what world does a tankless heater last longer, with less maintenance than a tank?

You would likley need to descale a tankless heater once a year (running chemicals through your piping) which isn't good for it either.

Can you circulate the water so you don't have to wait?

Point of use is a definite no go.
I'd go tank and circulate.

 

[Arby]

Thanks, guys. Besides space being precious in this small house, I didn't want to go with a traditional tank heater because of the cost to keep the water hot all the time...particularly being that we're gone often, for days at a time.

And I had read that tankless heaters lasted longer than the tank heaters. But I wouldn't know from personal experience. I just know that we've been getting 8-15 years from our tank heaters. On one, I had to replace a burned out element within ~4-5 years.

JG- What do you mean when you ask if I can circulate so I don't have to wait?

 

[Twowaxhack]

Get the largest stiebel Elton tankless you can afford. Learn all you can about how it works before it breaks.

Be sure to tell your electrician you probably need a 2-300 amp electrical service. You’ll need a 29 kw or 36kw unit. At your incoming water temp you’ll need a large unit.

case closed for me. Good luck

 

[JG plumbing]

You either spend money on keeping water hot (which is made next to nothing with the new plastic water heaters) or you burn through tons of energy trying to heat it on demand. If you want a tankless get a tankless. I'm just telling you it's not cheaper or less maintenance.

The new plastic waste heaters are expensive, but loose almost no heat. I haven't decided how I feel about them. They do take up room.

 

[JG plumbing]

Circulating water through your pipes so it's always hot. It's what I do at my house and I love it.

 

[bartleyhs]

TwoWax is correct that Stiebel Elton is the best tankless, because you can use more than one fixture at a time. Most tankless will turn one fixture cold if the other fixture is used. The Elton lowers the pressure to compensate, but both will be hot.
However, for a one bed one bath the largest one would be completely unnecessary and would require a 300amp service (again excessive for a 1/1 house).
I have attached the sizing chart. you just need to know your gallons per minute and water temp to determine what you would need. I have a 3/2 house and got the largest that my 200 amp service could handle. It has been really good, but you are supposed to flush it with vinegar every month. I must admit I haven’t done that and we have hard water, so I assume it will not last as long as it should.

So to answer your questions, strickly my opinion here as a tankless user (sorry so long)
If you decide on the tankless...

Whole house definitely, Remember, if you are building your house, the tankless can be put just about anywhere. You might consider putting it closest to the bath and then it is in between the other two however, I haven’t noticed a long wait at any of our fixtures.
pros
I do like it better than the tank. I was able to turn the space where the tank was into a nice sized closet, great to have that extra space.
I love that the water is instantly hot. Mine is 5‘ from the masterbath , 15’ from Kitchen, about 30‘ from 2nd bath and laundry, and the wait time is not bad.
Con
You are supposed to flush it so often. I am sure the need to do that has a lot to do with the water quality, but it can be a pain. It requires a bucket filled with vinegar, two hoses and a pump. the pump circulates for an hour (an hour you can’t use water anywhere in the house).
Price. Mine (the 29) was $700. You will not need one that big. but there is the cost of the wiring also. If it is a ways from your breaker box the cost of wire alone is rediculous. Mine required three 2pole breakers, I think 30amp and a 200amp service. (a smaller unit like you would need, would probably only require two breakers and 100-150amp service). I was able to do the work myself, so just had to buy the stupidly expensive wire to run three 30’ lines. If I had to hire an electrician it would have been a deal-breaker. Not worth that much cost. Since you are building, it may not cost much more to make those changes.
As far as cost of use, our electric company is able to break down the cost of our appliances in our monthly bill. We average $13 for heating water. That seems high to me. Unfortunately , they did not do that breakdown when we had the tank, so I have no comparison.

If you do decide on the tank, I have a space saving suggestion. At many of the military housing we have lived in, they put a well insulated lean-to type closet on the outside of the building that had the water heater and ac unit. This made it so they could do the routine services without having to enter the house. Something like that, could keep you from taking space away from your small floor plan. If you chose the tank option I think you should do the recirculating as suggested. Hopefully, one of the pros will explain it more to you, but there have been MANY discussions on this forum about it, so if you do a search, you will come up with a lot of info.

 

[Twowaxhack]

@bartleyhs

The incoming cold water temp, the temp rise needed and the volume of hot water needed tells you the size you need.

Also what is the power availability. 240 volts will produce more than 208v with the same water heater.

So with 55 degree water Youll need a 50-55 degree temp rise for a shower.

The 36kw unit will flow a max of 4.25 gpm at a 55 degree temp rise with 240v of power.

Same 36kw unit only flows 3.5gpm with 208v

And that’s only to get the water 110 degrees so you’ll be showering with all hot water.

I’d get the biggest one they made, or the next size down at minimum.

I wouldn’t like to not be able to wash clothes or dishes because I’m about to take a shower and don’t want reduced flow or have the unit max out every time I use it because I sized it small.

Read the fine print on the sizing guides. Remember they’re trying to sell you a water heater.......

Also your tankless will not get you hot water any faster at the faucet than a tank type. The distance from the heater to the fixture determines the purge time, unless it’s circulated.

 

[havasu]

You could simply walk over to the tanked water heater, move the dial to vacation mode, and you won't be heating the hot water until you return. I'm with the others, the maintenance of a tankless, along with not having a reserve amount of potable water for emergencies, and no power/no hot water is enough for me to not want to go back to a tankless water heater anytime soon.

 

[Arby]

TwoWax is correct that Stiebel Elton is the best tankless, because you can use more than one fixture at a time. Most tankless will turn one fixture cold if the other fixture is used. The Elton lowers the pressure to compensate, but both will be hot.
However, for a one bed one bath the largest one would be completely unnecessary and would require a 300amp service (again excessive for a 1/1 house).
I have attached the sizing chart. you just need to know your gallons per minute and water temp to determine what you would need. I have a 3/2 house and got the largest that my 200 amp service could handle. It has been really good, but you are supposed to flush it with vinegar every month. I must admit I haven’t done that and we have hard water, so I assume it will not last as long as it should.

So to answer your questions, strickly my opinion here as a tankless user (sorry so long)
If you decide on the tankless...

Whole house definitely, Remember, if you are building your house, the tankless can be put just about anywhere. You might consider putting it closest to the bath and then it is in between the other two however, I haven’t noticed a long wait at any of our fixtures.
pros
I do like it better than the tank. I was able to turn the space where the tank was into a nice sized closet, great to have that extra space.
I love that the water is instantly hot. Mine is 5‘ from the masterbath , 15’ from Kitchen, about 30‘ from 2nd bath and laundry, and the wait time is not bad.
Con
You are supposed to flush it so often. I am sure the need to do that has a lot to do with the water quality, but it can be a pain. It requires a bucket filled with vinegar, two hoses and a pump. the pump circulates for an hour (an hour you can’t use water anywhere in the house).
Price. Mine (the 29) was $700. You will not need one that big. but there is the cost of the wiring also. If it is a ways from your breaker box the cost of wire alone is rediculous. Mine required three 2pole breakers, I think 30amp and a 200amp service. (a smaller unit like you would need, would probably only require two breakers and 100-150amp service). I was able to do the work myself, so just had to buy the stupidly expensive wire to run three 30’ lines. If I had to hire an electrician it would have been a deal-breaker. Not worth that much cost. Since you are building, it may not cost much more to make those changes.
As far as cost of use, our electric company is able to break down the cost of our appliances in our monthly bill. We average $13 for heating water. That seems high to me. Unfortunately , they did not do that breakdown when we had the tank, so I have no comparison.

If you do decide on the tank, I have a space saving suggestion. At many of the military housing we have lived in, they put a well insulated lean-to type closet on the outside of the building that had the water heater and ac unit. This made it so they could do the routine services without having to enter the house. Something like that, could keep you from taking space away from your small floor plan. If you chose the tank option I think you should do the recirculating as suggested. Hopefully, one of the pros will explain it more to you, but there have been MANY discussions on this forum about it, so if you do a search, you will come up with a lot of info.

Thanks for all that info!

Thanks to the other posters as well. Much appreciated!

Have to admit though, I'm confused. Based on what I have read and what a friend told me who lived in France, most everyone in Europe uses tankless. And most of what I read about tankless prior to coming here to ask, was mostly good. So....are the Europeans using a different and better technology? Are the benefits I've read about based on those differences...if there are any? Or....is the reason they're so common in Europe due to something else entirely?

I'm not questioning the knowledge shared here but rather trying to make sense of the differences. I'm just thinking there must be some logical reason most Euros are using tankless.

 

[Twowaxhack]

Thanks for all that info!

Thanks to the other posters as well. Much appreciated!

Have to admit though, I'm confused. Based on what I have read and what a friend told me who lived in France, most everyone in Europe uses tankless. And most of what I read about tankless prior to coming here to ask, was mostly good. So....are the Europeans using a different and better technology? Are the benefits I've read about based on those differences...if there are any? Or....is the reason they're so common in Europe due to something else entirely?

I'm not questioning the knowledge shared here but rather trying to make sense of the differences. I'm just thinking there must be some logical reason most Euros are using tankless.

Are they using electric tankless ? They might shower with 1 gallon a minute.

A shower has different meaning around the world. Americans set it at 2.5 gallons a minute per head. But you can have more than one head.

I like around 3.5 gallons for a shower. Legal limit is 2.5

 

[Arby]

Are they using electric tankless ? They might shower with 1 gallon a minute.

A shower has different meaning around the world. Americans set it at 2.5 gallons a minute per head. But you can have more than one head.

I like around 3.5 gallons for a shower. Legal limit is 2.5

I just talked to my buddy and his in France was electric. He thought most of the others were too...but can't be certain.

Not sure if you're talking about the GPM that comes out of a head but the one we currently have is rated at 1 GPM and I love it. Prior, we had a .75 GPM. It put out a fine high pressure like spray that almost stung upon hitting my skin. I liked it but like our current 1 GPM better.

 

[Twowaxhack]

I just talked to my buddy and his in France was electric. He thought most of the others were too...but can't be certain.

Not sure if you're talking about the GPM that comes out of a head but the one we currently have is rated at 1 GPM and I love it. Prior, we had a .75 GPM. It put out a fine high pressure like spray that almost stung upon hitting my skin. I liked it but like our current 1 GPM better.

Yeah, see that’s the difference in people.

I suggest getting the smallest one you possibly can .

 

[bartleyhs]

When I lived in greece they all had them or solar water heaters on the roofs. I wondered then, why they work there, but people in the US don’t think they would work. It was not long after we returned to the states the tankless began becoming popular here. The US seems to always be behind on this kind of stuff. Probably poitics, and the pros liking what they know and being skeptical change. But also, in europe they have 220 running through the entire house so, no biggy hooking something like this up.
Like I said. I do like the tankless better than the tank. I have had no problem with it whatsoever, and the space savings is a slam dunk.
With a tank, I hated being in the shower and having the temp get too hot when someone, say flushes a toilet, then gets cold when it’s done filling. This brand tankless is the only one I know of that prevents that from happening. I have never had any issues with others using water in the house while I’m in the shower. You dont even notice it. When we bought ours, the Stiebel Eltron was the only brand with that protection.
I posted the chart to help you see if it is even an option for you, I agree you should go one size up from what it recommends, but in no way would I consider installing a 300amp service so I could get the biggest one that requires four 2pole breakers, in a 1/1 house.
If I was building a 1/1 house from scratch I would 100% go tankless IF
1. I had at least 150amp service (the smaller units for 100amp services are not going to make you happy. In that case you would probably be better with the tank.
2. My water pressure was high enough - something I failed to mention is the tankless simply will not heat if the incoming water pressure is too low. About a week after we got ours, the water was cold. I figured out the whole house water filters were past due on changing, and they were restricting the water pressure too much. As long as we keep up on that, we have had no further issues. I love it, and I recommend this brand, but I wanted you to be aware it’s alittle more complicated than it seems, with added expense to run the required wiring.
You did ask a forum for opinions, it’s not surprising you would get conflicting opinions.
I am not a plumber, but I am confident of my positive review of this brand of tankless, since I have had one for 4 years now, and have been glad every time my hubby flushes the toilet while I’m in the shower, or I put something in my new closet, that I changed over to tankless.