We have had a bizarre leak in our house, which sent water trickling down both sides of the kitchen window & through the wall. It started last night, and we could not work out where it was coming from. First we thought it was rainwater coming in through the roof, then we thought it might be the loo, then the radiator, then the loo again: plumber was just about to start taking the floor up & knocking holes in the wall - when he finally worked out that it was being caused by a knackered old washer on the tap in the basin which had been standing innocently to one side pretending not to be involved.
"I feel like Columbo sometimes in this job' he told me, with enormous satisfaction.
Why do plumbers always SHOW you the knackered washer? Is one supposed to go round checking them every week or something? What are you supposed to say? (I always nod sagely but I have no idea if there is an expected response...)