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Tankless Coil

I have a contractor who wants to set up a tankless coil water heater within a steam boiler. I was wondering if this is a good idea. I was under the impression that tankless coils were very inefficient.


  • Charlie from wmass
    Charlie from wmass Member Posts: 4,281
    Depends on the use

    for small homes with low hot water use and a relatively small boiler they are ok. If used as a heat exchanger for a hot water loop they are also ok.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Brad White
    Brad White Member Posts: 2,393
    As Charlie said

    it depends on the usage. The inefficiency come in when you keep the boiler hot all the time on the off-chance that you want to wash a plate or your face. If not kept hot, you will have to wait.

    Boilers in general and steam boilers in particular get really upset when asked to write, "what I did on my summer vacation" essays.

    If you already have a tankless heater, you can improve it by installing a, well, a tank! A made for the application insulated stainless tank or electric water heater as an approved vessel. This tank would be connected to the tankless coil with a bronze circulator to "charge the tank". You would draw off this tank allowing small usage without firing the boiler and a buffer volume to allow the boiler to fire, then rest.

    Without this tank, your boiler will fire with every gallon you draw.
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
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