Thank you. I will definitely getting a second opinion before allowing this plumber to dig up the floor. I will get another plumber to check the pressure release valve and the pump speed. The original plumber does seem to be clutching at straws, and has made several different diagnoses, which haven't worked. But he says he's 100% convinced that the overflowing problem is caused by a leak in a pipe under a cement floor. So a new copper cylinder costs around £150, and fitting it would take roughly how long? Would it be more than one hour's labour? Just trying to get an idea of the worst case scenario (apart from a new boiler, which is what British Gas said, a snip at £5000...)
ks101
March 2009