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tankless electric water heater any thoughts??

Post in 'DIY and General non-hearth advice' started by petemal, Jan 26, 2012.

  1. petemal

    petemal Member

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    IS THAT A TANKLESS SYSTEM what brand and type

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  2. hoverfly

    hoverfly Minister of Fire

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    To heavy, I don't think the weight could be supported, but I could be wrong. It's also one of the more expensive options, leaving out a back up options like propane heat and hot water and a back up generator.
  3. Dr.Faustus

    Dr.Faustus Burning Hunk

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    a few years back i was considering all this as well. I was looking into either a propane or electric tankless water heater. after doing a lot of research, i came to the conclusion that the unit is pricey, it will suck up a lot of electric and i'll never see payback, and with propane i might have eventually seen payback *if* the unit held up against my extremely hard and 900ppm TDS well water.

    so went with the 40 gallon middle of the road standard tank from home depot. it raised the bill 25 to 30 a month for electric, sometimes less but not more than that. we use cold water to wash clothes. the dishwasher uses hot water but i dont think it uses a lot of it.

    we never run out of hot water even back to back showers. may only run out if wife fills the jacuzzi tub with hot water but recovers in 10 15 minutes.

    i think i made the right decision. i'm happy and oil-free.
  4. ablejoy

    ablejoy Feeling the Heat

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    I bought one of those pricey tankless water heaters last year mine is propane. The wife has a spa tub and now never runs out of hot water. Hope it holds up I put the water softener on the hot water side before the softener. So far so good
  5. krooser

    krooser Minister of Fire

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    Yep... it's sorta the middle capacity one I think...maybe an American Standard or Rheem? I'll check tomorrow on the brand...can't remember.
  6. Pellet-King

    Pellet-King Minister of Fire

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    For the money you spend on a tankless you can buy 3 tank models, the energy use is close to being the same, I'm cheap and do whatever is the cheapest way, why i burn pellets
  7. rickwai

    rickwai Feeling the Heat

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    I have a propane standard 40 gal water heater. My wife and I and a 11 yr old daughter. We rarely run out of HW. Occasionally if the girls go first I will get shorted. It does recover quickly. The tankless units have way to many controls for me. To much potential for breakdown, and when you opoen the front and see the circuits boards ect. it just screams high repair cost. I just cant see the advantage unless you have a high demand and dont have room for a large hw tank.
  8. 1Dtml

    1Dtml Feeling the Heat

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    For those that have corrosive and or hard water problems this condition effects all plumbing hardware not only oil fired, and needs to be corrected to stop its effects.

    1D
  9. hoverfly

    hoverfly Minister of Fire

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    Though the tanks are insulated better than in the past, you still pay for the additional heat loss in storing such a large mass. Therefore your savings in a thankless is not having to store the water.
  10. 76brian

    76brian Feeling the Heat

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    I lol'd at that part.

    I don't know if it was supposed to be funny, but i still found it funny.
  11. Fish On

    Fish On Feeling the Heat

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    well funny how this subject came up, walking into the basement after work and wow my hot water heater was leaking. were lucky that this winter sucks for snow because we would be riding right now, talk about a major flood when when we did come home. so quick wet vac cranking and a major disaster adverted.

    total bummer I got 15 years out of it and now I'm wondering if i should just install an electric.

    if gas was an option i would do a tank less.
  12. petemal

    petemal Member

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    sorry for the loss but 15 uears aint bad look at the rheem rte 18 i think its instant electric people have been saying some goods things about it
  13. Fish On

    Fish On Feeling the Heat

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    That would be an option but I think it would be not enough to keep up in my house, Plus the cost for me to run the wire and it needs 75 amp I think, got plenty of room because I rewired my whole house and panel.

    So I will more then likely go with oil like I had, just sucks because natural gas is just not in my area and I would go nuts looking at a propane tank outside.
  14. rkshed

    rkshed Feeling the Heat

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    I looked at tankless last year and a common theme was that they are not the best in colder climates. I could never find out for sure why, but a $300 electric tank was a safer bet for me.
  15. krooser

    krooser Minister of Fire

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    This spring I want to hook up a hot water line to a new outside water bib so i can have hot water for my pressure washer....
  16. Krik

    Krik Member

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    Because most of the time the cold water coming into the house is a lot colder than in warmer climates, and the tankless needs to put more energy into heating it to a specific temp at the same flow rate. It's the same issue as with geothermal heating. The mid-winter 6 ft deep soil temperature difference between Maine and Florida, for example, is easily 25F, and the tankless will have to put in at least 25% extra heating power to get it to 120F (which is a substantially larger tankless and electric requirements).

    Another option is to use a heat pump hot water heater. Normally these also suck in cold climates, because they work by extracting heat from the air. So your precious heating dollars are wasted, or your basement is simply too cold to make the heat pump work and the thing reverts to resistance heating. BUT, if you have a wood or pellet stove in the basement and keep it relatively warm (60F or so), you might come out ahead. I'll compare tank to tank, so we can leave out standby loss for a minute.

    In my conservative estimates, I'll say the heat pump has a cop of 2.25 - that is, for every KW of electric you put in, it pulls 1.25 KW of heat out of the air to heat the water with 2.25 KW. Also, I'll assume the pellet stove is a measly 70% efficient. In my world, with $0.15 per KW electric and $275 per ton of pellets, this means that a $1 electric heating unit is the same as $0.56 pellet heating unit. So if I spend $2.25 for 100% electric, I'd spend $1.70 for heat pump, which is roughly 25% savings. If you heat with cheap $199/ton pellets it's $1.50 for the heat pump, which is 33% less. Don't think a tankless can easily beat that unless your hot water usage is really low (and the price of the two should be very similar).

    The number one requirement is that the space with the water heater is heated by wood/pellet stove air and that it stays relatively warm. A big if, but I think it might just work for some folks on the forum.
  17. hoverfly

    hoverfly Minister of Fire

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    Nice!!
  18. fadippides

    fadippides New Member

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  19. hoverfly

    hoverfly Minister of Fire

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    I forgot about those new hw heat pumps.
  20. hoverfly

    hoverfly Minister of Fire

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    Well I guess the tank less hw just got "tanked". If you use a tank-less boiler for both heat and hw with an indirect that would work just fine. If not a the best option if you still need back up heat and lets face it everbody loves unlimited supply of hot water.
  21. woodgeek

    woodgeek Minister of Fire

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    Lots of good info on this thread....I've looked at this a bit, and it seems clear that for gas/propane, the flue losses are so high in a tank system that a tankless system saves you 30% in operating cost over a tank. Whether you make back the higher cost of the tankless depends on your fuel cost.

    BUT, in an electric tank, the losses are so low (<15%) that the it is really hard to see how you can make back the upfront cost on a tankless electric (and 75A wiring). For that kind of money you could get a HP tank unit (even if you only ran it in HP mode during the warm season) and come out way ahead after a few years. IMO, the electric tankless make the most sense in special applications, like add on bathrooms a mile from the boiler, apts without anyplace to stick a tank, etc.

    To the OP with the indirect...if the boiler is cold start, your standby usage should be really low if the setup is properly installed/insulated. At the current price of oil and elec, the cost per BTU is close, so if the standby can be eliminated, you can just use the hardware you have...
  22. Retired Guy

    Retired Guy Feeling the Heat

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    Before installing an electric tankless on demand water heater, I would seriously consider a Marathon. If I didn't have NG that's what I would do.

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