"Terry Pinnell" wrote in message
...
The house suddenly lost power a couple of days ago and on checking the
circuit breaker box I found the one controlling the immersion heater
had tripped. But that is not switched on (it hardly ever is), so how
could a leak be detected by the circuit breaker?

After resetting that breaker there has been no re-occurrence, but with
a two week holiday imminent I'm nervous that it may happen again. It's
no big deal to return to a house with maybe some of my
electronically-controlled devices switched on (lights, radio, TV,
garden waterfall, etc), as occasionally happens due to storm
lightning, or a widespread power failure, but the fridge and freezer
would be a major issue.

The immersion heater cable from the heater coil on top of the hot
water tank in the airing cupboard goes directly to the switch on the
wall, with no intervening mains plug/socket. So presumably, to get an
ohm reading on this unit to test for leakage, I have to first switch
off at the breaker box, remove the switch panel in the airing
cupboard, unscrew a connection, and work from there?

Any practical advice would be much appreciated please.

--
Terry, West Sussex, UK

The immersion heater switch is normally a double pole type, so if it's
switched off, the heater element is completely isolated anyway, so cannot be
responsible for for its feed MCB detecting leakage. When you say that your
house had lost all power, was the actual consumer unit breaker tripped, as
well as the immersion heater MCB, leading you to believe that an immersion
heater failure had tripped both ?

Arfa