Tankless Water Heaters

  • Posted by a hidden member.
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    Feb 04, 2009 4:23 AM GMT
    I'm thinking about having a tankless model installed to replace my hot H2O tank. A couple questions:

    1. Does anyone in northern climate have one and still maintain hot H2O for a shower?

    2. Is water pressure compromised from a regular shower?

  • TallGWMvballe...

    Posts: 1925

    Feb 04, 2009 6:59 PM GMT
    Water pressure has nothing to do with what heating system you use so the answer is that a Tankless water heater also known as a demand system will have whatever is your house water pressure as determined by your pressure regulator which is between the street and your home.

    Even tank heaters will have a delay in supplying hot water as the pipe between the heater and the shower head will have cold water that has to pass through. The Demand (Tankless) heaters are really a good thing for small families or single people or those who aren't always at home.

    They provide really quick hot water nearly as fast at the tank heaters and for most situations will be much more efficient therefor less expensive to run.


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    Feb 04, 2009 7:17 PM GMT
    And see, I need a new water heater and was thinkin about one of these (at the suggestion of my dad) as well...

    And here on RJ, an infomercial on Tankless Water Heaters.
    Who knew?

    Thanks!
    I had those same questions and how cool I have the answers now!
    You guys rock.
  • Mikeylikesit

    Posts: 1021

    Feb 04, 2009 7:19 PM GMT
    Tankless water heaters are fine. A few people in my complex have them. Only problem. You have to be carefull of hard water, around here we have alot of hard water. That can comprimise the effectiveness of them....icon_lol.gif
  • metta

    Posts: 39090

    Feb 04, 2009 7:29 PM GMT
    Tankless water heaters are excellent and very efficient. I wish that I would have had one put in my home when they were building it but we had to start cutting out some of the upgrades we wanted to keep costs down and that was one of them. The upgrade that I really wanted but also had to cut out was the beveled framed mirrors for the bathrooms.

    I had a recirculating pump installed to my water heater that is on a timer. It circulates the hot water into the pipes during the times that I request (for me, it is in the mornings) so I don't have to run the water wait for the hot water. I don't know if this is also done with the tankless sytems. But I would highly recommend it for the tank systems.
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    Feb 04, 2009 7:50 PM GMT
    I have two, one in the house and one in the lab. I've got moderately hard water (60 to 80 ppm as CaCO3) and have no problems. They're great. When you're not actually using hot water, they use no energy at all. When you want it, you get as much as you want. Shower for an hour (or with a friend.) Plus you get a closet back, because they don't take up much space.

    The electric ones do require a lot of amps, so the hook up for your old tank is probably not adequate. Gas ones shouldn't be a problem.

    I do have to adjust the thermostat between summer and winter. Basically, it heats the water to shower temperature (not scalding) so you just use the hot tap only. Mixing hot and cold is kind of a waste of energy anyway. The amount of power applied depends on the flow rate, so you have to learn to set the flow and leave it while using hot water. If you keep adjusting the flow, the heater control never reaches equilibrium.
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    Feb 04, 2009 7:54 PM GMT
    An unexpected topic for a thread - at first I thought it must be some perverse double entendre.
    That said, tankless water heaters are cost- and energy efficient because the heating element is on only when you need the water, instead of all the time. They're more expensive to install, but supposedly save money in the long run. (This testimonial comes from the utility guy who just replaced my water heater. I ended up getting the tank model because I didn't want to spend the extra money).
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    Feb 04, 2009 8:02 PM GMT
    All good info here, absolutely a good choice for a residence. And I don't know if the same things are available in Alberta, but in Ontario the provincial government often has rebate programmes in effect where you can get reimbursed some of the costs of the unit when you're replacing your old boiler.
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    Feb 04, 2009 8:30 PM GMT
    We have a demand water heater, and it's fair. Saves money, but one quirk is the tendency for the output heat to vary when you first draw on it. Mainly a problem in the shower, where we have to adjust the water temp a few times up & down before it stabilizes.

    Another is that it won't kick in if the water flow is very low. So that having a hot water trickle in the sink won't always work.
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    Feb 04, 2009 8:38 PM GMT
    I work for a plumbing company. Tankless is more expensive, but require less maintenance compared to the tank models. The space saved can range from about 1 sq ft in your mechanical room to being installed on the OUTSIDE of your home! The smallest model can handle up to 3 showers. They come with a 10 year warranty on the heat exchanger and a 3 year warranty on parts. The life expectancy on one is 10-15 years.

    The great thing about these is that you will NEVER run out of hot water!
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    Feb 04, 2009 10:41 PM GMT
    We were guests in a house with a tankless water heater, and while it worked fine for the shower, running the hot water full blast to fill the bathtub only produced ever so slightly warmed water. We're big on taking long hot baths, so on that basis alone, we would never get one.

    The hot water heater in our new addition is one of those noisy power vent units, and we keep it plugged in to a light timer so that it only runs once a day for about an hour. That keeps the noise to a minimum and saves energy as well.
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    Feb 04, 2009 11:09 PM GMT
    mindgarden saidI have two, one in the house and one in the lab. I've got moderately hard water (60 to 80 ppm as CaCO3) and have no problems. They're great. When you're not actually using hot water, they use no energy at all. When you want it, you get as much as you want. Shower for an hour (or with a friend.) Plus you get a closet back, because they don't take up much space.

    The electric ones do require a lot of amps, so the hook up for your old tank is probably not adequate. Gas ones shouldn't be a problem.

    I do have to adjust the thermostat between summer and winter. Basically, it heats the water to shower temperature (not scalding) so you just use the hot tap only. Mixing hot and cold is kind of a waste of energy anyway. The amount of power applied depends on the flow rate, so you have to learn to set the flow and leave it while using hot water. If you keep adjusting the flow, the heater control never reaches equilibrium.

    I listen to "The Money Pit" podcasts each week, and almost every reference to tankless water heaters, the main guy says it needs to be gas--electric would be completely inefficient and a waste of initial investment.
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    Feb 04, 2009 11:21 PM GMT
    Wow, what an unexpected topic.

    My BFF (at least in my mind) from This Old House, Richard Trethewey, says this about tankless heaters:

    "They work beautifully and are made of stainless steel, so they last. The up side is that you could shower for 24 hours straight. The down side is that it makes a limited amount of water per minute, so two major uses of hot water cannot happen at the same time. They are perfect in smaller use applications, such as vacation homes, campers, or boats."

    Here's a link to the rest of his thughts on tankless. http://www.thisoldhouse.com/toh/asktoh/question/0,,213064,00.html

    I've seen them use tankless several times on the show. I doubt they would keep using them if people were having problems with them. I think you just need to use them in the right situtations.