Hot water is leaking from the overflow pipe on the cold water tank on the roof. Also, while the radiators get very hot, the water isn't heating up properly. The problems began after a powerflush. The boiler is old, but I'm told is a good one, an Ideal Mexico. The plumber who did the powerflush wants to dig up a concrete floor to find a suspected leak in a pipe. Will this cure the problem, or is it more likely to be something to do with the thermostat?

ks101, March 2009

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

Ideal Mexico is a standard floor standing boiler one of the very best.Hope the power flush hasnt knackered the copper cylinder.Is the pump speed set too high as it could be pumping over.As for the t/stat,it cant be that as when they go the boiler never shuts down.It just goes on and on periodically shunting water over the expansion.Cant see the digging up of the floor curing the hot water problem though.The power flush could have blown a hole in the coil in the cylinder causing the domestic and c/h water to mix.

Tony S, March 2009

where the overflow pipe is , is there a pressure relief valve there, usally set at 3 bar?

Ben, March 2009