"Ken Knott" wrote in message
om...
i have just fitted a resettable immersion heater thermostat. It has a
dial to select the temperature and a reset button. Since you can
select the temperature using the dial i don't really understand what
resettable means in this context. can anyone explain? thanks.

Sounds like its intended to be used in series with a standard immersion stat
for use in an unvented cylinder. I recently replaced an immersion in an
unvented cylinder and it had two thermostats inside, one of which was manual
reset.