"maddening" wrote in message
...
....
sure does, thanks very much. Now to find a good electrician!

Good luck. I recently spent about a week trying to track down an
intermittent fault that was tripping an RCD at unpredictable intervals. It
didn't help that I was not familiar with the wiring and that none of the c30
circuits on the board were marked. It was fairly simple to isolate which
circuit was causing the problem, but finding out the fault was another
matter.

In the end it proved to be a plumbing fault. A pipe had blown off the top of
the pump from the well and the RCD tripped when it pumped out enough water
to fill the pump house up to the level of the lowest electrical connection.
As the time taken to do that varied according to how long the circuit had
been switched off, it could take anything from a few minutes to about an
hour to trip. I had not considered looking at the well, as all the taps were
working and I had (evidently wrongly) been told that only the supply to the
kitchen was on mains water. If it had been dry I might have tried to water
the garden, when I would have noticed a lack of water.

Colin Bignell