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  1. #1

    Anyone going tankless these days?

    Looking for opinions on whether to go with a new tankless water heater to replace aging conventional tank style. Pros and cons would be appreciated. Recommended brands also appreciated.

  2. #2
    Join Date
    Dec 2008
    Location
    Seattle
    Posts
    105

    I always have a tough time on this question from

    customers. My usual questions are, 1) do you have high flow shower heads? 2) How many people in house? Do you really want to be energy minded, ie reduce water useage, gas useage etc. This sometimes takes giving up on multiple showers running at same time, flow restricted shower heads etc. Are you willing to spend a couple grand more than standard water heater. These all come into play. Demand water heaters do have limitations to max flow rate through them. Usually meaning one shower at a time. No large tub fill spouts either as they a lot of the time exceed the max throughput of an on demand unless you bank them together to handle really high flows and that gets quite expensive. They are also much more complicated also but they do seem to be fairly reliable but when they do have problems it can sometimes be hard to find a good tech on them. Be that all said, they are efficient and do produce hot water at a reasonable rate. In other words, I am still on the fence and alway's have to talk myself into it before I can give client a good recommendation. Tim

  3. #3
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    If you use a lot of hot water, a gas tank-less heater makes sense. A single person with no hot tub... makes less sense. The tank less costs a lot and more to install as a replacement. If you use a lot of hot water then it makes sense due to efficiency improvement and speed of making water hot. For low use applications there is a long payback period.
    Remember, Air Conditioning begins with AIR.

  4. #4
    Join Date
    Mar 2003
    Location
    PA/DE area
    Posts
    1,535

    Talking

    Consumer Reports did a story and you can go to their website and read it,it was eye opening! I am one that does not consider it the BIBLE, but another point in which to refer.
    It's NOT the BRAND,it's the company that installs it!!!!!

  5. #5
    Join Date
    Dec 2008
    Location
    Tacoma, WA
    Posts
    90
    I'm not a professional, but I have had a Rinnai tankless unit for about 3 months. I replaced a traditional tank unit. My $.02:

    1. I may not live to see the payback! The Rinnai is an expensive unit. My wife and I decided that we would do this more from the perspective of reducing our carbon footprint than from thinking we'd save money ourselves, though if we're here long enough, we might.

    2. The unit has worked as advertised. Water pressure has reduced modestly, but not enough to make us feel as if we're lacking in the shower or anywhere else.

    3. The largest disadvantage for us is the so-called "cold water sandwich," which is inevitable (we're told) with tankless units. What happens every night is this....my wife runs the hot water tap until the water is warm as she washes her face, etc. She turns off the tap. A few minutes later, I get into the shower. The water is, of course, warm. BUT, the unit has shut off when she turned off the tap. When I turn the shower on, there is a small amount of cold water that flows through the system before the unit fires up and starts to deliver hot water. This means that if I step into the shower immediately, before that "cold water sandwich" has passed through the shower head, I get a nice chilly (lukewarm, really) minute or so. And, since the master bath is at the end of the pipe, it takes several minutes for the water to make it that far. This is a minor annoyance for us, not a deal breaker.

    As one site put it, "North America is the about the only place left where energy is cheap enough for it to be affordable to keep water hot 24/7. Everywhere else uses tankless."

    My $.02 worth....

  6. #6
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    238
    I have been considering one of these:
    http://www.myhomehardware.com/servle...ing/Categories
    I reserviced my house to 400 amps shortly after I bought it just for this purpose.

    But I want ot install one of these first:
    http://www.renewability.com/powerpipe.htm

  7. #7
    Join Date
    Sep 2008
    Location
    Milwaukee,WI
    Posts
    12
    Make sure that your electrical service can handle the amp draw when these things kick on. Not sure about all brands but I have seen problems on some older houses because of this.

  8. #8
    [QUOTE=rcamner;2085754]I'm not a professional, but I have had a Rinnai tankless unit for about 3 months. I replaced a traditional tank unit. My $.02:
    ....my wife runs the hot water tap until the water is warm

    How much time are you talking here? Are they THAT much more$ than a tank style? Thanks. Do they work with a forced hot water boiler?

  9. #9
    Join Date
    Mar 2007
    Location
    Myrtle Beach, SC
    Posts
    2,919
    Quote Originally Posted by drsmith012 View Post
    I have been considering one of these:
    http://www.myhomehardware.com/servle...ing/Categories
    I reserviced my house to 400 amps shortly after I bought it just for this purpose.

    But I want ot install one of these first:
    http://www.renewability.com/powerpipe.htm
    Be careful.... around here if you install an electric tank-less water heater you can fry the pole or pad transformer. When the power company replaces the transformer, they find who is drawing the extra power. Then they put that customer on a DEMAND meter, just like a commercial customer. Then they get billed for the how fast they use power as well as the power they use. The electric bill can triple!!!!

    The power pipe looks pie in the sky to me. Depending on the house, installation costs could be considerable. Depending on where the discharge fresh water runs, it could be re-cooled by ambient conditions, negating the purported savings.


    It may be different where you are, but you may want to check into that first.
    Last edited by Kevin O'Neill; 01-02-2009 at 07:25 PM. Reason: Addition
    Remember, Air Conditioning begins with AIR.

  10. #10
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    238
    Quote Originally Posted by Kevin O'Neill View Post
    Be careful.... around here if you install an electric tank-less water heater you can fry the pole or pad transformer. When the power company replaces the transformer, they find who is drawing the extra power. Then they put that customer on a DEMAND meter, just like a commercial customer. Then they get billed for the how fast they use power as well as the power they use. The electric bill can triple!!!!

    The power pipe looks pie in the sky to me. Depending on the house, installation costs could be considerable. Depending on where the discharge fresh water runs, it could be re-cooled by ambient conditions, negating the purported savings.


    It may be different where you are, but you may want to check into that first.
    I talked to the engineer for the power company directly as I was doing the reservice myself. He made no mention of them requiring a demand meter or any special billing. In fact he sugested going to their peak billing cycle as I could potentially save even more money with peak metering and a tankless waterheater. He did mention that ot the two poll transformers that I could connect to both probably do not have the capacity to handle my load. In that case the one I am on would have to be upgraded but not at my cost. It would be pretty easy to figure out who is pulling the most power off the transformer I am on. All connections are 2/0 overhead wire. My feeder is 350kcmil underground. It won't take too long to figure that out.

    As for the power pipe I was considering building one myself but a little more advance. I was going to use a three ton compressor to capture the waste heat but found the passive ones to be suffeciently effecient for thier simplicity, intiail cost and cost of operation. I will probably install on in the next year or so as my 50 year old galvinized drain pipes have about had it. I would also insulate all pipes and have a second main stack. One for the grey water from the bathrooms and the other for the toilets. There is a minor problem regarding the current main stack that necitates breaking up the basement floor so adding another stack would not be a problem.

  11. #11
    Join Date
    May 2004
    Location
    south louisiana
    Posts
    3,163
    gas tankless would be worth the investment, and may be available for a tax credit this year..if energy factor is 85 or better

    electric tankless are expensive to run and as pointed out above may be more than existing panels can handle.

    I don't recomend electric tankless.
    The cure of the part should not be attempted without the cure of the whole. ~Plato

  12. #12
    Join Date
    Jan 2007
    Location
    Minneapolis, MN
    Posts
    415
    There is no benefit to using an electric on demand unless it is for point of use like one sink. Using something like the Marathon http://www.marathonheaters.com/ is just as efficient, almost no standby loss, and our utility has an off peak program the cuts the kw charge in half.

  13. #13
    Quote Originally Posted by Kevin O'Neill View Post
    ...The power pipe looks pie in the sky to me. Depending on the house, installation costs could be considerable. Depending on where the discharge fresh water runs, it could be re-cooled by ambient conditions, negating the purported savings.

    It may be different where you are, but you may want to check into that first.
    I can imagine such a gadget might work in a situation where there is a near-constant flow of wastewater - a large office building, restaurant, factory, etc. However, in a home? Unless you've got six teenagers taking long showers throughout the day, well, I just don't see it working very well...

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