Tankless Water Heater

[rwalters]

I planning the construction of a small (900sf) living area attached to a barn. I am planning to use an electric tankless water heater. I am in Texas where extreme cold is not a significant issue. I was wondering if anyone had any experience with these heaters?

[roger g]

I haven't but a friend of mine has installed lots of them and is impressed. The one he installs are gas fired and is used in most part for heating hot water for heating pipes in floors as well as washing. The one problem he did have (not sure whether he solved it) was that when the burner ignited there had to be a certain flow rate of water through the boiler. Apparently that if you used an energy saving shower head ( small flow) the burner would kick out and the result would be hot/cold/hot/cold. I kinda think he installed a storage tank for the hot water. A storage tank looks just like an electric hot water tank but without the heat element.
Europe has had these years ago. I saw them probably 50 years ago when I was kid. Lotsa stuff in the world that isn't over here.

roger

[bkrahmer]

I don't have personal experience, but have done a lot of reading on the gas-fired ones. The problem that Roger mentioned may be due to the model of the unit involved. Bosch has a unit, for example, that requires no electricity. It uses the movement of the water to power the electronics. Their 'normal units', though, seem pretty advanced. They can modulate their heat, so using preheated water from other sources is an option. I'm planning on using one in that way. I'm going to have a hot water storage tank that will be preheated by wood, and perhaps by solar. The on-demand heater will then fully heat the water for domestic hot water heater as well as for the hydronic heating system. The plan is to utilize solar in the summer, and wood in the winter, to reduce heating and hot water costs.

[rwalters]

Thank you for your responses. The area where I am building is very rural and I am not sure there are any gas lines. I really don't want to mess with propane. I will be the only person living there and, as I said, extreme cold is not a real problem in Texas. So, I think it should work satisfactorily. I am also thinking of putting a smaller model out in the barn area so that I can bathe the horses in warm water.

Just so you know, besides the economy, the reason I am so interested in this is that the heater in my current home has burst twice. The original heater burs, I replaced it with a unit from Sears. A little over a year later the new unit leaked. Come to find out, though, that this was probably because the installer installed it incorrectly. He capped the pressure relief port on the side and put the relief valve on the output side.

[VALENT]

we put an electric tankless heater for use at the coast (also in Texas) and it has worked well. We only use it occassionally and its small size is a real help.

[rwalters]

Thank you. What brand electric heater did you use?

[N2Deep]

We just installed 2 of these to run the whole house and they seem to work great. I wish I would have installed two handle valves for the showers -it would make it a little easier to adjust the temp. I used SETS brand and they are electric- no gas in my area.

[rwalters]

N2deep, thanks. SETS was one of the heaters I was looking at. How did you purchase your units? Did you buy them over the net, or from a local dealer?

Thanks again!

[N2Deep]

I ordered them over the net- same price most places. And no local dealers near- Heck I couldn't even find anybody that new anything about them. So now everyone is asking me about them :D

[rwalters]

I thank everyone who replied. I feel much better about my decision now.

Thanks!

[rbyrby2]

Regarding brands of tankless water heaters, several builders here on central OK use Rinnai systems. I am currently building a new home, and using a "preheat tank" - well water into a storage tank that is lined with a coil from the geothermal ground loop. Should cut down even more on cost, especially with propane costs going up. I'll know in about 6 months if design turns into reality.

[rwalters]

I appreciate your response. However, Rinnai only makes gas heaters and I am not particularly interested in a gas heater. Unless I hear some reason why I shouldn't, I think I am going with a SETS brand heater.

Thanks again!

[BPINC]

I believe Bosch makes an electric one. It takes about 80 amps at 220 volts though.

[Tom_E]

:? I have no experince with electrical models but have approx 20 years of user use with gas models (Propane) I am a very strong advocate of them and think that you will be pleased with your decision. I have had Bosch and Myson (english) units in a previous home. Currentley in a bath/utility room in a shop I have an Elite ( polish) unit. The Bosch unit will go in the new home we are building. The Myson was a good unit but required periodic maintenance, but in all fairness the maintance may have been due to it's location. The Elite unit serves the purpose but control features on it leave a lot to be desired.
Aqua Star was bought out by Bosch so I have been told. I know they made electric models and imagine that Bosch has continued the pratice.
A personal opinion if you please; The high up front cost continues to be one of the big drawbacks of the acceptance in the US of the units. It is hard to get people to embrace the idea (fact) of payback via the engery cost of storing hot water.
Like a previous post mentioned encountering the units years back in Europe, I first encountered these units in Japan in 1963.

[giddonah]

Off hand, what are the costs? Has anyone retrofitted them?

[Vector]

The units themselves run around $600-700 for a single major use unit (one shower/washing machine filling at a tie) or about $1000 for a unit that can handle two major applications at once.

Installation shouldn't be any more expensive than a normal unit, though you may wish to re-route the plumbing, as most of the units are wall-mounted, which might not just drop in where your current water heater is.

You might also need to run new gas piping, as the units require a much higher input BTU than tank heaters. The Bosh/AquaStar 250SX I'm going to be installing in our new house requires 175,000 input BTUs.

I first encountered them back about ten years ago in Europe, and have wanted one ever since.

[giddonah]

Is there any application that makes a traditional heater more effective/efficient/whatever than a tankless (like one that services a large house for instance)? If so, does anyone know where the line is drawn between the two?

[N2Deep]

I would think that if you have a recirculator or radiant floor heating a tankless wouldn't be the best.

One tip if you go tankless install two handle shower valves -one for hot and one for cold, it makes it much easier to adjust the temp.

[giddonah]

I think I'm sold. Now, to google recirculator... :oops: :wink:

[giddonah]

http://www.houseneeds.com/shop/plumbing/recirculators/chillipepper/chillimainpage.htm

Says right at the bottom, works with tankless. Another cool thing to think about :)

[bkrahmer]

This is just an FYI, but recirculators save water and add a bit of convenience, but waste energy. A friend of mine turned me on to them, but when I read more about them, I decided against using them in my house.

[giddonah]

Good to know, thanks.

[Russell]

I have retrofitted a gas unit in my house. If I remember right the initial cost was around $500 for the unit and all plumbing supplies and took one afternoon to accomplish. The one thing I didn't plan on was having to replumb most of the house due to corrosion in the hot water pipes and having to increase the flue size to 6". Oh the joys of remodeling!! One thing to consider is the incomining water temperature. In the winter time my unit does not put out much water to fill the bathtub or washer. It is fine for showers and dishes. So consider moving up to a larger unit than you think you need.