tankless water heaters

[seriousvol]

would like comments from anyone who has used one for the whole house.

[islandr]

I'd be interested in opinions as well., since I'm hoping to use one for the whole house as well. I'm also planning to have at least one jetted tub. It sure sounds like a good way to go, particularly if you don't use alot of water.

[Andythompson]

I researched them about three years ago as a replacement for my conventional home water heater. The only thing negative about them (at that time) was that the tankless hotwater heater might have a problem keeping up with two major appilances demanding hot water at the same time ( trying to do a load of dishes and washing a load of clothes, etc). If you think that might be an issue for you, I believe that they now make a higher capacity unit which addresses that problem.

Another issue was that even the smaller unit required a 5 inch flue vent instead of the standard 3 inch found on a conventional water heater. Not really an issue for new construction but potentially a real problem for a retrofit.

Other than those two things I couldn't find anything negative about them. They claim that they are highly efficient and will reduce your hot water cost by tons of dollars!!!!

You might try a google search or a search on "Epinions.com"

let me know what you find out. I, too, have thought it would be a good solution for a new construction project.

Andy
11/04 Alumni

[GammaRae]

Don't forget about the point-of-use instant hot water heaters, either. This is the way we are planning on doing it and it seems to be the hot setup.

[KakarotMF]

I don't have any experience w/ the whole house tankless versions, but I've installed 60+ Point-of-Use small ones. The major advantage to the small ones is that you don't need an expansion tank (the size of a basketball tied to the cold line entering the water heater) or a overflow-drain (1") run-off terminating 6" above the ground. This allows them to be put in offices that have a little bar sink. If you get a more powerful model (7.5 kW) you can do 2 sinks back to back or up to 10 LF away. (That's 10' of WATERLINE length, not 10' as the crow flies!) Most if not all require 240 V, so check that if you want to add one post-construction. Also, so can be used as "boosters" to up the temperature; others can't.

I've used 2 manufacturers: Eemax (www.eemax.com) and Hot Aqua, and have had trouble on both. Choose your poison carefully! The Eemaxe's elements can pop/burn if you get an air bubble in the line, which will eventually happen if you're on city water. Hot Aqua's don't have that problem (different element set-up) but the model I used required a high pressure to set them off. If you're on a well and getting only 40 psi (plenty in it's own right) you might have problems.

[gregorama]

I had the "pleasure" of living with 3 of them for 5 years at a remote lodge in Alaska back in the 80's. The problem I had was they would not ignite unless the water was really flowing. If you had a low-flow shower head or aerator on the sink, you had to open it wide to ensure a steady ignition. We also had spotty pressure, since we didn't have enough head on our storage tank to supply multiple users at one time. So if cabin A was taking a shower and Cabin B turned on as well, you may not have enough flow to get any hot at all. Not lukewarm, survivable showers, just AAAAAAAGGGGHHHHH WHERESTHEF'NMAINTENANCEGUY :shock: cold showers. The technology may have improved since then, especially if you're on a municipal system with adequate (read oversize) plumbing, but for my money and low maintenance, a tanked hot water heater lights my fire. Waste heat just goes into the house, anyway...

just my 2 centavos...

[jbeall]

How about propane whole house tankless hot water heaters, anybody here got experience with them?

It seems to be that electric is all the rage with these tankless hot water heaters, but it would seem to me that Propane and Natural Gas might actually be cheaper ways to heat the water...

Any thoughts on this?

For what it's worth, in my area propane is going for $1.999/gallon and power is at $0.08/kWh.

We're thinking of buying an old house that needs a bit of work--it will serve two purposes:

1) We can live in it and it's big enough for my family (and future kids that may arrive in the next decade), but about half the cost of what a nicer house of the same size would be
2) It's on 7 acres of land, and when we're ready to build, we could subdivide off another lot and build a log home there while we live in the old farm house.

This property is a foreclosure, and we're going to go into it assuming all the appliances are toast and need repair. I'm trying to decide whether we should go whole house tankless hot water, point of use tankless, or just put in a good ol' fashioned tank.

This is a four full bath farmhouse, so I'm thinking if we go whole house tankless, it's going to be a monster setup--and the house only has 200 amp server at the moment.

-Josh

[rckclmbr428]

if this house is somewhere you dont expect to stay, could you justify the added expense? or would you take the tankless with you when you moved?

[LeighG]

Just FYI -

I installed a small tankless HW heater in my rental unit. I was surprised at how big a vent it required. Normally, you need a 4" vent for a natural gas tank hot water heater - but the tankless needed 6" as I recall. It was new construction and I put the tankless in the attic - so the vent run was fairly short (but extends a long way above the roof to get sufficient draw.) When the unit is operating - it's quite a blowtorch inside!

Possibly a propane unit would need less venting than a natural gas unit (seems to me that propane burns hotter). It would be a bummer to get a tankless unit home, start the install, and discover you need a much larger vent up through the house and out of the roof. Replacing the vent stack is a much larger/involved/expensive job than simply replacing the water heater. Especially if it's in the basement and the vent stack runs up thru inside walls.

Leigh

[Shark]

Basil had a long post about his experience with this type of water heater.....a search should find it...

[Vern Street]

We used a propane heater in our apartment we built to live in while building the loghome with the intentions of using it in the log home when the time came. However, I didn't want to remove it from the apartment so I purchased an electric unit (Titan) for the log home. Both units work great however if you need a large unit, i.,e, provide enough hot water for multiple bathrooms, I would recommend the propane as they can provide a lot more heat. The electric unit requires a lot of power. My Titan uses 220v at 55Amp while it is on. This provides enough hot water for one bathroom at a time. The larger electric units use 2 sets of breakers and lots of amps. The Titan and the Bosch PowerStar are both fairly inexpensive (about $200) so you could use two of them in multiple bathrooms.

I liked the propane unit better but didn't want to have to cut the vent through my roof on my log home. The propane unit I have is a Bosch available from Lowes at about $500 and here in Okla, we got a $250 rebate for "green".

The main thing about using a tankless water is you have to understand how they work. They simply raise the incoming water temp up "X" degrees where "X" is a function of flow so if you are in the shower with it all adjusted and someone turns on the clothes washer or something else that requires hot water, "X" will change causing the shower to cool down. Not a problem, you just need to be aware of how it works. Also, the water will be warmer in the summer than when in winter as the inlet water temp is colder in the winter.

The big - big advantage is (Sara loves it), you never run out of hot water so those long showers are great or if you have six kids using it, you still have hot water when they are thru.

In summary, if you can do the vent pipe, use the propane unit but if not, use multiple electric units to distribute the hot water and the power required.

Vern in Oklahoma
www.vernstreet.com
moved in and loving it!

[jbeall]

if this house is somewhere you dont expect to stay, could you justify the added expense? or would you take the tankless with you when you moved?

We expect we'll be there for a while, maybe as long as 10 or 15 years.

And I suppose we could take it with us--don't see why not.

[jbeall]

Basil had a long post about his experience with this type of water heater.....a search should find it...

<a href='/warning-about-ondemand-hot-water'>Here it is.</a>

I laughed out loud when he said he could hear it whining at a friends house that was a mile away. I'm imaging the sound of a jet engine in my basement...

[RPM]

41 days until the class! Just thought I'd "rub it in". After reading your post last month, I know you feel 2 months will seem like an eternity! Well, I can't wait either! 41 days is going to take forever! I feel like a kid marking the calendar waiting for Christmas! See you in class!

Ray

[edkemper]

Seems to me if I had a large family I'd seriously consider am A.O Smith (Vortex) Water heater. http://www.hotwater.com/products/residential/rg-vertex100.html .

I'll be building very minimal so I'm going to go with the on-demand heaters.

[WillandHelen]

I have a point of use one in my shop. 2 problems.

1) water temp dependent on incoming water temp and flow rate.

2) Shuts off at a flow rate way above the amount of hot water I often want.

Maybe the really good ones solve these problems, if not I would never buy one for my house, but fine for a shop or bar sink.

[panderson03]

I have a point of use one in my shop. 2 problems.

1) water temp dependent on incoming water temp and flow rate.

2) Shuts off at a flow rate way above the amount of hot water I often want.

Maybe the really good ones solve these problems, if not I would never buy one for my house, but fine for a shop or bar sink.

would you be willing to tell us what brand of point of use hot water heater you bought? we're seriously consider these for our DHW and for our in floor radiant heat.
thanks very much!

[WillandHelen]

Stiebel Eltron was the brand I bought.

[panderson03]

THANKS! (.... never heard of it...will have to research them)!!

[adz]

I have a Rinai, and we love it.
Plenty of hot water. Fits in a small closet on outside wall. Installed it myself.
No more tank leakage problems.

[Bramlar]

No tank leaking, but the heat exchanger could someday.
Says a Rinai repair man.
Changed one out last year that a home owner had incorrectly installed himself.
Not saying that you did adz, or that Rinai is bad.
If I had propane I would install a Rinai myself.

[Garrettscabinplace]

I installed a Rheem tankless hot water heater in my home 2 years ago. I did it myself and it has been great to use. I have 4 children with 2 teenagers and so having a constant supply of hot water is a bonus. We have no problem running 2 appliances or showers at one time, but that is the limit. We just manage your water usage a little better. My unit is Natural gas and I only use a 3" vent going directly out the side of my house.
I have had one problem with the unit since I owned it and it was relatively easy to fix once Rheem sent me the replacement circuit board. It took a while to trouble shoot with going through the various error codes that displayed on the unit. It only took about 1/2 hr to replace the board and once I did that, I was up and running again.
Overall, I have been pleased with performance.