i have a potterton puma 100e combi boiler , i did think for a while that the expansion vessel was going but now i'm not so sure.
it runs away fine until intermitently when running hot water ( particularly the bathroom tap ? ) the pressure in the boiler will start to rise and if i'm not quick enough to switch off the boiler the pressure gets so high the prv activates.
we have the temp control for the hot water turned down but the hot water is still boiling hot !
as a trial i rechecked the pressure in the vessel and also drained the kitchen radiator and deliberately left it half full of air incase the pressure vessel was not functioning properly but the same fault has kept occuring since doing this so i'm now wondering if the water is overheating somehow and causing the pressure to spike and activate the prv ?
any thoughts
it runs away fine until intermitently when running hot water ( particularly the bathroom tap ? ) the pressure in the boiler will start to rise and if i'm not quick enough to switch off the boiler the pressure gets so high the prv activates.
we have the temp control for the hot water turned down but the hot water is still boiling hot !
as a trial i rechecked the pressure in the vessel and also drained the kitchen radiator and deliberately left it half full of air incase the pressure vessel was not functioning properly but the same fault has kept occuring since doing this so i'm now wondering if the water is overheating somehow and causing the pressure to spike and activate the prv ?
any thoughts