This has been happening for a couple of years, but I'm still interested to know why.......
I have a 'power shower' with a pump in the airing cupboard. This is fed by a pipe down from the cold tank in the loft, and a pipe teed-off from the hot water out pipe from the tank, which is also in the airing cupboard. All output pipes from the pump then all go straight up, through the loft and then back down the wall on the other side of the bathroom, to an Aqualisa thermostatic mixer.
Sometimes, when I turn the shower on, especially if it is very cold, only cold water will come out of the shower head and it will never get warm. The pump also sounds to be labouring a bit.
But, if I turn on one of the hot taps in the bathroom so the water runs hot first, then the above problem never happens. If I was to put it in terms of what seems to be happening, the mixer almost seems to go into thermal shock when it experiences the cold water, and closes off the hot supply to it.
Isn't normally an issue, as I usually get up first and always remember to do the hot-tap running thing first, but sometimes my wife gets up first, never remembers, and has to turn the whole thing off and on again a few times before the shower works properly. Would like to understand what is happening though, and if I can do anything about it.
I have a 'power shower' with a pump in the airing cupboard. This is fed by a pipe down from the cold tank in the loft, and a pipe teed-off from the hot water out pipe from the tank, which is also in the airing cupboard. All output pipes from the pump then all go straight up, through the loft and then back down the wall on the other side of the bathroom, to an Aqualisa thermostatic mixer.
Sometimes, when I turn the shower on, especially if it is very cold, only cold water will come out of the shower head and it will never get warm. The pump also sounds to be labouring a bit.
But, if I turn on one of the hot taps in the bathroom so the water runs hot first, then the above problem never happens. If I was to put it in terms of what seems to be happening, the mixer almost seems to go into thermal shock when it experiences the cold water, and closes off the hot supply to it.
Isn't normally an issue, as I usually get up first and always remember to do the hot-tap running thing first, but sometimes my wife gets up first, never remembers, and has to turn the whole thing off and on again a few times before the shower works properly. Would like to understand what is happening though, and if I can do anything about it.
