Apologies that this topic has been covered before but I haven't found symptoms the same as mine in previous posts.
I have a Potterton Promax boiler, about 10 yrs old I think. This seems to work fine, heating the water and rads via a 3-way valve. The problem I have is that the cold water tank (the large one, not the heating expansion tank) overflows when all the hot water has been used up. This has showed up recently in hot weather when I haven't been heating as much water and it has run out a couple of times. The rads have not been on for some time.
I have replaced the cold feed ballcock but (warm) water still comes up into the tank from the expansion pipe so the overflow constantly runs. When this happened recently I stopped it by running the boiler for 30 mins and heating up some water.
May not be relevant but I have a 3-storey house with the cold water tank in the loft. Hot water tank is just below it in an airing cupboard. Boiler on the ground floor.
Any suggestions ?
I have a Potterton Promax boiler, about 10 yrs old I think. This seems to work fine, heating the water and rads via a 3-way valve. The problem I have is that the cold water tank (the large one, not the heating expansion tank) overflows when all the hot water has been used up. This has showed up recently in hot weather when I haven't been heating as much water and it has run out a couple of times. The rads have not been on for some time.
I have replaced the cold feed ballcock but (warm) water still comes up into the tank from the expansion pipe so the overflow constantly runs. When this happened recently I stopped it by running the boiler for 30 mins and heating up some water.
May not be relevant but I have a 3-storey house with the cold water tank in the loft. Hot water tank is just below it in an airing cupboard. Boiler on the ground floor.
Any suggestions ?