"Sam Goldwasser" wrote in message
...
"Mike Kennedy" writes:

Sounds like the heating element in an electric hot water heater. Unless
it
is some kind of thermostat.

No, it is the sacrificial galvanic magnesium rod used to miminize the
corrosion of the steel tank.


http://popularmechanics.com/home_imp...water_heaters/


And they're readily available and not horribly expensive. The only snag you
may run into is that there's sometimes not enough ceiling clearance above
the water heater to replace it. In that case you need to disconnect the
plumbing, drain the tank, and tip the whole unit out a bit.