Your info is a little sketchy. Does the wall thermostat control all the
heat? Is there only one breaker that feeds all the heat? The wall heater
most likely is not 22KW, but probably has a blower in it, which could squeal
on occasion. It's also possible that bad contacts in an electric heat line
voltage thermostat, could make a hissing sound when closing. If so, I'd have
it replaced.



"Theo" (reply w/o spam) wrote in message
...
My garage has a studio with electric baseboard heat in one room and an
electric wall heater in the entryway. It's expensive to run - something
like
22 kW - so I mainly use that room in warm weather.

The entryway thermostat is an "Electromode Model M7-D double line break"
with a huge bimetallic strip. At random intervals, a kind of
screeching/hissing sound comes from it. (At least, I think that's where it
comes from. It never happens when I'm right near it.) I pulled the double
breaker than powers the baseboards, and turned the thermostat built into
the
wall heater all the way down. So there shouldn't be any current flowing,
right? So where does the noise come from, and can I do anything about it
w/o
cutting wires?

Thanks!

Theo