I got several responses to my post re Dave Garth's ingenious water heater design
asking for more info.  Since my initial post, i got the parts together and actually
"installed" or built a replica of Dave's heater.  I tested it last night when i
drove from my place near the ocean in san francisco to the san francisco
airport...20 minutes away.  when i got to the airport, i turned on the faucet and
washed my hands and face with ... really nice hot water.

I tapped into the heater hoses with tees under the rear heater box.  i rane one line
into a 24 volt ac selonoid valve, which fits under the rear heater box.  from there,
i ran 1/4" copper tubing into the hidden utiltiy compartment and up into the water
tank.  I heated a 1" piece of metal pipe to burn 1" holes in the top of the tank to
run the 1/4" line.  i used rubber gromets to seal the pipe and holes....got larger
ones to protect the palstic from heat.  i then coiled 15' of 1/4" copper tubing and
inserted it into the tank.  it did not take up much room at all.

i moved the water level gauge from the tank lid to the tank where it is out of the
way (it's  nicer there)  i used 90 degree flared elbows at the top of the tank to
connect the submeresed coil to the feed and return lines running from the heater
hoses.  i insulated the lines where i thought appropriate to protect from burns and
to protect wiring.

i hooked up a main power switch for the selonoid valve.  this, in turn, is hooked up
to the water bed thermostat.  if the water temp is below 105 degrees, the
therrmostat allows power to flow to the selonoid valve,which causes the valve to
open, and the coolant to flow.  when the temp reaches about 108 degrees, the
thermostat cuts off  power to the valve, and the coolant flow stops so that it does
not become dangerously hot.

i have not field tested the set up yet.  i want to add a copper heating coil that i
can place on the stove to heat water when stationary...does anyone know wheter i can
use thermal siphoning to circulate water from the water tank through a copper coil
on the stove and back into the water tank, or do i need to use a pump?

a parts list follows.  feel free to e-mail if you need more info.

steve...
'90 syncro westy

i ended up using compression fittings and flared fittings.  i used both because i
could not find everything i needed in either type.  i used the following:

two 1/2" brass tees with compression fittings to tap into the heater hoses at rear
heater;

two 1/2" to 3/8" reducers with compression fittings

one 3/8" flared to 1/2" pipe threaded fitting, which bolts into the selonoid valve;

one 1/2" threaded pipe to 3/8" flared fitting, which bolts on other side of
selonoid;
one 3/8" flared to 1/4" flared reducer
____________
one 3/8" to 1/4" flared reducer (for the return line)
________________
4 1/4" flare nuts
2 3/8" fare nuts
_____________

25' of 1/4" copper tubing
 18" of 3/8" copper tubing
 1' of 1/2" inch copper tubing
_____________________

one  high temperature selenoid
valve (1a582) and 24 volt AC selenoid from Grangier (800-225-5994) for $98 total.
__________
-one waterbed thermostat (get a mechanical one...not electronic like i did)
-rubber gromets for sealing water tank where coolant lines enter and exit
-one lighted electrical switch
 -in line fuse
-sealed (not loose) pipe insulation
-pipe joint goop

PACO wrote:

> Text item: Text Item
>
> Steve,
>
> I wanted to discuss this although my comments may be a little late.  I haven't
> received the list again until today.
>
> I too am a fan of Dave's work.  I mirrored his heater installation note for note
> and still take satisfaction from the design advantages.
>
> I also want a way to heat water.  Primarily because I camp a lot in winter and
> want to keep water in the holding tank without it freezing.  I rejected the
> design in the end because it would not keep the water lines from freezing and I
> was very concerned that should the system leak in any way the water would be
> rendered highly non-potable and the poison taste might be masked under the taste
> of some hot chocolate scarped down after a busy day outside or something.
>
> What use will you put your heated water to?  A shower?  Will you still use the
> tank to hold drinking water?
>
> Thanks, -Clark