Does anyone use tankless hot water heaters for parts of your house (or your entire house)? It seems a whole house system isn't ideal for this part of the country but specific use ones might be. We have a smaller hot water heater that barely makes it through 2 showers. I was thinking of installing one for the primary shower so it won't run out of hot water or prevent the rest of the house from having hot water.

I am wondering if it would make sense and save us from investing in a larger hot water heater that may not be as efficient as hot water on demand. It seems the shower is the biggest consumer of hot water. Otherwise, we use very little (for now).

If you end up installing one, please post your experiences. I've been thinking about installing one of them for years, and having one in the bathroom would make perfect sense.

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No matter where you go, there you are. (b.banzai)

Theres alot of things to think about in the scenario.

If you put in a tankless to feed the one bathroom, ideally it should be as CLOSE to the bathroom as possible. (dealy in getting hot water).
If you dont have a way to vent the exhaust of a gas flame you are limited to an electric unit. 220v is probably more efficient than 110v. Is there room in your current breaker box for that?
Now you have to run 220v or 110v to the location. It probably should be on a dedicated breaker (I dunno the code on this).

Assuming your wash room backs up against a closet where you can hide the tankless heater - can you afford the loss of closet space?

What about the pipes to that bathroom - where do they run and can you intercept them to put in the tankless unit? (the pipes may not run near the closet where you plan to hide the tankless heater).

If you put in the tankless unit in the utility room with the current heater - are the pipes that feed the bathroom in question seperated from the rest of the house supply so that the heater can just feed the one bathroom? (I have not seen many homes where the water supply pipes were run in a "single run to a room/fixture from a manifold in the utility room". The ONLY house I have seen that was done that way was a full custom home where the owner (a friend of mine) paid alot of $ to have it done that way. Even if they are - how far is the run to the bathroom? You may end up having to put in circulators to get hot water at a reasonable time period.

Accorrding to my internet research - there are some "operator beware" issues about how one turns on water that is connected to a tankless setup (something about flow rates - low flow wasnt efficient - I forget).

I dont have tankless but have been thinking about going tankless.
As far as I can tell
-- there is a HUGE up front cost compared to "traditional" water tank - esp if you are talking replacement
-- there are some infrasctucture optimization issues (the way that the pipes are run).
-- Converting a house setup for a single hot water tank to "multiple" hot water sources is neither simple nor inexpensive.

As far as I can tell - in my situation - the "ROI" on going tankless is NOT THERE from a pure $$$ perspective.
That does not mean I still dont plan to go tankless - just that there are alot fo costs to factor in on the project.

without a doubt you are going to spend more on a tankless heater vs. a traditional hot water heater. you're really trading off the cost of constantly heating a 50,60,70+ gallon hot water heater all the time in the off chance you need to run the shower for 3 people simultaneously vs. the upfront cost of installing something that will turn on only when you need it.

I think it would make most sense to put in one of these units to drive a bathroom that had a jacuzzi tub as well as a shower. To do it for just a normal bath/shower combo seems overkill. just like it seems overkill to have a 75gal tank sitting there being lit all the time just on the off chance I want to fill a two-person tub.

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No matter where you go, there you are. (b.banzai)

The flow rates are dependent on how many degrees it has to raise the temperature of the water. The higher the volume or the greater the temperature differential increases the chance the water is not heated to the desired temperature.

I propose a simple solution for you.

- Put the tankless water heater right after your normal water heater.

- Set your tank water heater to the lowest possible setting.

Your tank water heater will then preheat the incoming water enough that your tankless unit will not be overworked while at the same time you significantly diminish the amount of energy necessary to keep your tank water at shower temp.

It should be sufficient to give you an endless supply of hot water.

Also, tankless units can pay for themselves in energy savings. Especially since you get a tax credit if they meet certain energy standards.

Now, there is one distinct advantage to putting a smaller unit right at the entrance to the pipes in your bathroom. You save on water because you will not need to let the shower run for several minutes before the hot water gets to you.

I would recommend to speak to a licensed plumber experienced with these devices to give you the best recommendation (or a corporate representative).

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Czar of the 26th Ward.

I guess this is why more people don't have them. They don't seem well suited to older homes at least.

I am not completely discouraged. I will look into how difficult/feasible it would be do in our home. At least I have a better sense of the challenges to doing this. Thanks Kaizen for the thorough reply. If anyone who has done this has feedback I would love to read about your experiences.

Thanks!

They make circulators to address the delay issue.

The more energy conscious ones are keyed to a trigger (say the bathroom light) and will turn off when the water in the pipes reaches a certian temp.

We installed a Tankless Hot Water Heater last year and all is well. The plumber tried over and over again to talk us out of it because it would never provide enough hot water for what we will need. Fortunately he was completely wrong. He heard it from another plumber who heard it from another plumber and so on ... Also the way they rate the tankless models is different than the tanks it's not 30,40,50 gallons or whatever it's gallons per minute.

The big problem we had was that we didn't have a way to vent to the outside of the house our basement doesn't extend in the back under our kitchen, and you have to vent at least 7' up if it goes out toward a sidewalk. Or they require Category 5 or 3 or something really expensive venting for all the power vent/newer models.

So I found a legacy tech that vents through regular household venting (you just need 7 inch off the heater and then adapted down to what goes up your chimney.)

There is a pretty extensive discussion here ....

http://www.phillyblog.com/philly/ask...er-heater.html

And if you get a low flow shower head that takes 1.5 gallons per minute if your tankless is rated for 4 gallons per minute in the dead of winter you can be running 2 showers (we only have one so no worries there) and still have a gallon per minute for washing machine and/or dishwasher.

The only drawback is that it takes maybe 30-50 seconds for the water temperature to heat up, but it used to take almost as long for the hot water to work it's way through the pipes up the bathroom anyway.

As to energy savings probably not so much as when you can take a 5 hour hot shower you tend to ... were as in the past you'd jump out when the water started getting cold. But the thing should last a good 20-30 years (fingers crossed.)

My plumber was very vehement about it not putting out enough hot water but when in all my googling I kept finding these things being sold by car wash supply places and comments from car wash owners in Minnesota and such ... I was pretty sure it could keep up with a shower, washing machine and dishwasher all at the same time.

Easy way to be sure is just check your appliance manuals for how many gallons per minute they require at peak use, if you don't know what your shower uses put a bucket of a known # of gallons and time how long it takes to fill.

http://www.palomatankless.com/produc...gacy_ph24.html

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Plus they have electric ones which wouldn't require any venting.

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Czar of the 26th Ward.

My understanding is that they do suck up a lot of electric though ... and since we already have gas was best to stick with that. Also the whole house water heaters don't come in electric if I recall ... just the Point of Service ones like if you have it only in the bathroom.

My understanding with those models is that they are mostly used in seasonal places or to provide and assist to a solar hot water heater. I don't think they can raise the temp of the water very far very fast like the gas ones do. I know that the unit I have kicks out like 99,000 BTUs when raising the water from the 30's to the 130's.

Other potential downside with my model (though it hasn't bothered us) is that it's not electric so you need to adjust the temp manually like twice a year. I think my water heater basically raises the temp 60 degrees or 100 degrees (with some variation in between) so in the winter you crank it and when the ground warms up in late spring you crank it back down. So you can't really get it to 115 or 120 or a specific temp, just +60 or +100.

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"All of this will not be finished in the first one hundred days, nor will it be finished in the first one thousand days, nor in the life of this administration, nor even perhaps in our lifetime on this planet. But let us begin."

~John F. Kennedy