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fairlaniac's avatar
fairlaniac
Explorer
Dec 29, 2020

Tankless heater in seasonal TT

We have a TT in a park near the beach in Delaware. I have the OEM propane hot water heater on board that we use in the off season. Water is off from 10/15 - 4/15 annually. IO have a 275 gallon IBC tank with fresh water to use in the off season. During season I have an electric hot water heater and I valve off the onboard water heater during spring/summer. The onboard heater developed a rust hole leak. I'm thinking about a tankless heater but I'm trying to figure out if my two heater system will cause issue? In the off season I use the 12V pump for my water and in spring/summer I use park water pressure. Would a tankless have issues with the different ways of getting water to the heater?

FYI - I don't use the electric heater in the off season because each time we leave off season I winterize and I would need to dump the 30 gallons in the electric heater each time. So we use the 6 gallon and do a typical winterize each time. 275 gallons lasts us 3-4 off season trips.

thanks,
Doug

4 Replies

  • fairlaniac's avatar
    fairlaniac
    Explorer
    Dec 30, 2020
    Thank you for the replies. Good info to know. I think we'll just make it easy and get a new propane R water heater.
  • DrewE's avatar
    DrewE
    Explorer II
    Dec 29, 2020
    valhalla360 wrote:

    - Now if you have a 50amp/240v supply, you can get a high wattage unit that can do the job (check the rating for temperature increase relative to flow)


    An 8 kW model (which is about the maximum you could reasonably hook to a 50A circuit and have some power left over for other things) would provide well less than 1 gpm with cool incoming water, and almost certainly be unsatisfactory for a shower. 15-20 kW might be a reasonable size, which requires at least a 100A service.
  • valhalla360's avatar
    valhalla360
    Navigator
    Dec 29, 2020
    Shouldn't have issues with the source of water pressure.

    The bigger question is what is the source of power for the water heater?
    - We had a propane one on our boat and I hated it because you had to fiddle with it a lot to get the temp right then if you adjusted the flow at all you either got an ice bath or scalded.
    - Electric ones need a lot of juice particularly if we are talking about the winter when the incoming water may only be in the mid 30F range. If you only have a 30amp power supply, you likely can't bring the temp up enough to have a reasonably warm shower.
    - Now if you have a 50amp/240v supply, you can get a high wattage unit that can do the job (check the rating for temperature increase relative to flow)
  • wanderingaimles's avatar
    wanderingaimles
    Explorer
    Dec 29, 2020
    Since you are working off a finite supply in the winter months I would stay with the rv type unit. less temptation to stretch out the showers and use your water faster.

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