Water heaters? Suburban, Atwood, American Standard, Potonthe Stove

[ronald b. kazi]

Rick,
Thanks for the excellent description. I will brave the elements and go out and
read the parts/shop manuals. I don't know if the tank I have can be adapted, I
would have to pull it to weld, so I will probably pull it regardless. Boat US
has a 6 gallon water heater with a heat exchanger built in that measures
13x13x19, which I think will fit. I will, of course, try to adapt what I have.
I am going to put in a 1500 watt element in, as I think the 14 guage wire can
handle it, especially over the short run to the circuit panel.

I just bought a new Dometic and will have to pull out the old fridge. That would
be a good time to run the hoses. I think I might also put a fan coil (JC Whitney
or Junkyard) in line to heat up the back while under way. Maybe under the seat or
possibly under the rear bed. A few extra coils in the bathroom with a shunt
might also keep my fanny warm in the winter but can be turned off in the summer.
Some strategically placed pipe insulation might also be in order. I will get this
thing to 13,000 lbs yet!

Ron and Julie
73 Painted Desert

> Ron,
> Engine coolant flows back to a very simple heat exchanger which is part of
> the OEM water heater. A 5/8" tube made of the same material as the water
> heater tank (aluminum, or stainless if you have a stainless tank) is welded
> to the front of the tank in a semicircle. It's only about 15" +/- in contact
> with the tank, but it's enough to transfer quite a lot of heat.
> The hot coolant is taken from the engine heater hoses via tee fittings.
> Hot coolant comes from a tee near the heater circuit "hot" source at the rear
> of the right head. Coolant returns to the "cool" side of the heater hose up
> near the AC clutch, just before the heater hose descends to the water pump
> suction fitting. The hoses swoop down behind the right front wheel well
> well, then rearward inboard of the rocker panel. Immediately behind the
> entrance door, the hoses make a 90 degree bend upward (originally via steel
> elbows, which were recalled due to rust-out failures). Travelling up in the
> wall space next to the door, they then turn rearward again through the
> refrigerator compartment, through the wall, and into the bath.
> Since it all uses engine coolant, no special winterization is necessary.
> Only disadvantage I can see is a tendency to heat up the bathroom counter in
> hot weather. OTOH, this additional heat is nice on a cold evening.
> There is some info in the shop manual, and good pictures in the parts
> manual.
> HTH.
>
> Rick Staples
> '75 Eleganza
> Louisville, CO

 

[ronald b. kazi]

I am thinking of modifying my tank and simply wrapping some copper tube around
the tank. If the tank is made of aluminum, I might change my mind unless I can
find some aluminum tube. If I can weld it to the outside (I have had aluminum
welding wire sitting for 11 years in my garage from the yacht yard I used to work
at ) great, if not, I have some epoxy that works great with aluminum. From the
emails I have received, there is a lot of heat generated by the system. I also
intend to hook up a fan coil unit in line with the water heater with a valve so
that I can heat the rear of the coach while under way and not have to use the
furnace.

Ron.

> In a message dated 3/12/00 6:40:36 PM Mountain Standard Time,

>
> Engine coolant flows back to a very simple heat exchanger which is part
> of
> the OEM water heater. A 5/8" tube made of the same material as the water
> heater tank (aluminum, or stainless if you have a stainless tank) is welded
> to the front of the tank in a semicircle. It's only about 15" +/- in
> contact
> with the tank, but it's enough to transfer quite a lot of heat. >>
>
> Hi Rick -- must be that GM made another design change or else changed
> vendors. My 77 hot water heater has a "well" built into the same side as the
> water lines and the heating element. There is a loop that has two hose
> fittings that go from the engine and back. This slides into the "well" and
> provides more surface area for heating.
>
> It is important to note that anyone contemplating modifying their heater
> should never just weld a pipe or tube through the tank and hook the hoses to
> the ends as the engine coolant contains ethylene glycol antifreeze which is
> poisonous, even in fairly small quantities. A pinhole or crack in a weld
> might cause the antifreeze to leak into the water heater.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM

 

[wayne nesbitt]

I replaced my aluminum water heater bottle with a stainless steal one last
year. It had developed a pin hole leak on the bottom of the tank.
I was surprised how heavy the aluminum bottle was. As an aside. If I had
know it was that heavy I may have had an aluminum patch put on it.

As you know the bottle sits inside a steel if I remember correctly
galvanised steel box separated by a layer of fiberglass insulation. Over the
years the insulation was packed down till at one spot the aluminum and steel
had come together exactly where the leak had developed by galvanic action of
dissimilar metals. I think you will be looking for trouble building a tubing
network around the outside of your tank especially if it runs underneath the
aluminum tank near the steel one.
JMO
Wayne