Arny Krueger wrote:

"Mike Rivers" wrote in message
news:znr1100735378k@trad
In article
writes:

Yes there is. All water heaters have an active electrical connection
because no water heater would heat water without it.

My gas water heater has no electrical connection to the outside world.
Any electricity involved with its operation is self-generated. There's
a temperature sensor (it's call a thermocouple in the book, but I've
never taken one apart) that holds the pilot valve open that I think
may be electrical, or maybe it's just a heat pipe.

I've taken them apart. They indeed are based on a bimetalic thermocouple or
thermocouple stack (thermopile). They activate a sensitive solenoid that
operates the gas valve.

http://hearth.com/what/gas/howgasworks.html

Now *that* actually sounds not dissimilar to my old gas water heater.

It opens the main burners automatically on demand for hot water.


Graham