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Dshawv's avatar
Dshawv
Explorer
Mar 17, 2016

Waterproofing tankless water heater install

I am installing a Girard tankless water heater in my tt. The new water heater is 13x13, while the old Atwood 6 gallon had a wider clearance. This will leave several inches open on either side of the new unit that must be closed up prior to water heater installation to prevent water damage. What is the best way to patch this? I have a '16 jayflight slx 28bhsw with aluminum siding. Was considering purchasing a small piece of siding, cutting it to fit, sealing it and fastening to the existing siding and studs framing the water heater. Thoughts? Any method your can think of that will allow me to patch this without a special order of siding? Entire patch will be behind water heater door so aesthetics aren't a concern. Sheet metal with butyl tape?

6 Replies

  • Pardon me bu, why didn't you but the adapter Kit? Convert from Atwood?
    $50.
  • You need to order the correct conversion door.
    For Atwood 6 gallon you need part number 2GWHDA6 and for 10 gallon Atwood you need part number 2GWHDAS10.
  • Just fit in some plywood like the pro's do and seal up around the door. I'm sure the pro's have a few tricks up their sleeve, to make it more presentable, of course that is why you have to pay more.


    The information is out there, all you have to do is let it in.
  • My only thought at the moment is do not use any silicon, it always fails and is very close to impossible to remove so any future sealing would fail.

    OSI Quad for caulking seems to be very well thought of in the RV community. Jim
  • As I said in my original post, the patched area will be covered by the new water heater door, so I could care less how it looks, just that it is sufficiently waterproof.
    I'm certain I can figure it out on my own, but I was also hoping some of the experienced rv'ers on this forum have encountered this sort of thing before and had something useful to share so that I might avoid any trial and error.
    Additional insight can't hurt and I'm trying to think this through before I start ripping stuff out or putting new holes in the trailer.
    This is our first tt and the wife isn't much of a roughing-it type of gal. We aren't full time and as long as it keeps her happy and lets her take a halfway decent shower it will be good enough for me. And if I it really doesn't work then we will have to return it and spend the extra money for a more high end brand of tankless.
  • Anything you do will possibly end up looking like a crappy patch.
    BTW good luck with that water heater. They realoy have mixed reviews.

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