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sirraf69

Electric Hot Water Question

sirraf69
9 years ago

The way our new house is designed, the hot water heater will basically be in the middle of the basement. The longest run of water line would be approximately 30-35 feet. I have done the first hour rating and a 50 gallon tank seems like it would supply plenty for us(3 people). My plumber has also suggested putting in a second heater closer to the kitchen/laundry. If we go with one heater, and with the long water line run, do we need one bigger than the 50 gal? Just curious if the 50 gal will supply the hot water in a decent time to all fixtures? Thanks

Comments (13)

  • dadoes
    9 years ago

    The capacity of the tank (unless it's so small that it can't fill the supply line) has no relation to delivery time of heated water to the fixtures. Delivery time is a factor of the distance from the water heater to the fixtures.

  • sirraf69
    Original Author
    9 years ago

    Dadoes,

    So would two tanks be the better option? The space in the basement would be close to the master and second bath. It would be 30-35 feet from kitchen, laundry, and a half bath.

  • jakethewonderdog
    9 years ago

    sirraf69,

    A couple of things: Dadoes is correct that distance is the primary consideration for how long it will take hot water to get there. Other things include the pipe size, how often water is used and if the pipes are insulated or not.

    Here's what I would suggest: Use a small electric tank heater (2.5 gal, for example) very near the point of use at the end near the bedroom in series with the main heater. This will get you hot water quickly until the hot water arrives from the main heater. Locate the main heater as close as you can to the Kitchen, Laundry, half-bath.

    Insulate all of your hot water lines.

    Also, consider a hybrid (heat pump) like the Geospring for the main heater. The money savings is considerable (about $365 a year) and there are often sizable rebates from utility companies as well. If you do purchase a hybrid, consider an extended warranty. Most of the reliability problems have been worked out of these heaters now, but they are still kinda new and it could make sense.

    The hybrid heater will make a little bit of noise ( like a refrigerator) so you will be better putting it near the kitchen rather than in the basement under the bedroom.

    link to small point of use heater: http://www.amazon.com/Rheem-PROE2-POU-Professional-Residential/dp/B00HR8P6CU

    I am not endorsing either of these products, just giving you a link for use as an example.

    Here is a link that might be useful: Geospring water heater

    This post was edited by jakethewonderdog on Fri, Sep 12, 14 at 17:22

  • tedred
    9 years ago

    Assuming that your pipes are 3/4 inches thick, 35 feet would make about 3/4 gallons of water in the pipes and wasting that amount of water everytime you open the faucet is something you want to avoid. I think a mini-tank that holds a few gallons of hot water would work fine. Hot water from the main unit would get to the kitchen before the mini-tank runs out of water. I'd go along with the plumber.

  • SaltiDawg
    9 years ago

    Recirc pump?

  • jakethewonderdog
    9 years ago

    Saltidawg,

    The economics of a recirc pump really suck unless it's "on demand".
    The small tank like Tedred and I mentioned is the way to go. I wouldn't do another full size tank like the plumber is mentioning though... just the two and a half gal POU heater. Can be mounted on the basement wall using a bracket.

    I hope the OP looks into the hybrid heater also. should be a perfect application.

  • SaltiDawg
    9 years ago

    On demand recirc pump... pump runs for a minute or so when you want hot water - turns itself off.

  • jakethewonderdog
    9 years ago

    Saltidog,

    You and I have had this conversation before. I agree, "on demand" is way to go if you install a circ pump.

    Most aren't done that way unfortunately. Most are on a timer / thermostat and waste a lot of heat.

    For roughly the same money they could do a POU heater in series with the main heater. Would have almost instant hot water.

  • SaltiDawg
    9 years ago

    Recirc under the sink at the remote location... push a button, tiny pump under the sink pumps from hot to cold under sink, runs a few minutes until pump turns off due to reaching set temperature.

    Under $200 if you install yourself. (And it works fine if you're planning to use either the shower or tub in same location.)

  • Elmer J Fudd
    9 years ago

    To each his own, but the systems that route water from a hot water pipe to a cold water pipe foul the taste of the house's cold water supply. For drinking, for coffee and tea, for any purpose. If you drink and cook with only bottled water, then it doesn't matter.

    Run out some hot water, let it cool in a glass, and then compare the taste of that to water from the cold line. In most houses, the taste difference is very noticeable and the hot is unpleasant.

    A true recirc system "recirculates", by running the no longer hot water in the hot pipe back to the heater without any cross contamination.

    I experienced this myself when staying at a friend's plush vacation home in the mountains. He was crowing over breakfast about all the features this newer place had that his main home didn't, but commented how disappointed he was that he was unable to brew good coffee there, despite the pure mountain water. I agreed, it tasted awful.

    A peak under the sink solved the mystery and I explained my possible explanation. After running the cold water from all the taps for a few minutes, the next pot of coffee met his expectations (for the first time in the several years he's owned the place).

  • SaltiDawg
    9 years ago

    With the pump at the heater, does not the system need an additional run of pipe from the heater to the remote location? May be impossible to do practically in an existing home.

    My next door neighbors have an under sink recirc in their Master Bath... it has no effect on the taste of cold water in the kitchen nor do they report any issue at the bathroom sink.

  • jakethewonderdog
    9 years ago

    The 2.5 gal POU water heater is $250 (don't know if there's a better deal out there) and solves the problem for the OP. It allows them a water heater near both ends of the house while still allowing for a centralized hi-efficiency main unit (such as a hybrid).

    If I'm plumbing for a new house and have to do a recirc pump, I'd install a return loop - no question about it.

  • Elmer J Fudd
    9 years ago

    Yes, as jake suggests, the best way to do it is with a return loop. And yes, that might not be possible in an existing house. In such a situation, I'd just live with the wait for hot water unless it was unbearable. I'd never put that water into the cold supply.

    Run the taste test yourself. Water that's been in and through a water heater usually tastes nasty. Besides being flavored by all the minerals that collect in a hot water system, the heating removes dissolved gases that can contribute positively to the taste.