Hot water heater power relay

[Ralph L. Fullenwider]

Mike:

The 12vdc is supplied from a hot source, but what your friend is looking
for is the red or black wire that is hooked to the ground source which is
the water from the water heater it's self. It is connected to a sensor
(plastic plug with a screw in it held by jb weld usually) at the out put
side of the water heater piping in a brass T fitting. when water is in the
piping it supplies the ground via the water and pulls the relay passing the
110 vac to the ecu and heating coil. tell your friend he can by pass the
ground but that defeats the safety, which is what it was intendeed to do to
begin with

Safe travels,

Ralph and Charolette Fullenwider
"84FC35 "Ruff Diamond"
Duncan, Oklahoma

At 04:27 AM 8/2/2011 +0000, you wrote:
>A friend with a 1986 PT40 called with a weird power problem to his hot
>water heater. He says the 110V power is routed through a relay in the 110
>power line before the normal on/off switch. It appears the relay is one
>of those 12V switched relays which controls the 110 power. He has not
>been able to trace it to see where the 12V leads go to. The relay appears
>to be stuck open now and he gets no power to the hot water heater. If he
>by-passes the relay, and turns the on/off switch on, he gets power and hot
>water.
>
>I do not remember having that set up on my 83, nor on my 91. Does anyone
>have a power setup like that for their hot water heater power? What is
>controlling the 12V power source? An over temperature switch/sensor
>somewhere? Or is this some prior owner's undocumented "upgrade"? He is
>concerned about just bypassing the relay without knowing what it is for.
>
>Thanks for any ideas.
>
>Mike Bulriss
>1991 WB40 "Texas Minivan" (with hot water)
>San Antonio, TX (balmy triple digits are us)
>
>