One further thought. Is the outside socket (into which the pump is plugged) switched? If so, do you know whether it's a SP or DP switch? Whatever, if it's switched, what happens (i.e. is there an RCD trip) if one switches the pump off with that switch? I'll keep thinking!Thanks for all your replies! Thought it was an interesting one to get your brains working.... And mine! Will let you know what I find on Saturday, but any more ideas in the mean time will be appreciated.. Cheers
Kind Regards, John