Just moved into a new flat and have strange problem with central heating. The boiler, a Potterton Suprima 60 L, looks fairly new. Much newer than the timer control or thermostat that's for sure. There is a separate hot-water circuit that feeds an immersion tank. The problem is this: When the water is switched off at the control panel the heating works fine: the rads go hot and cold depending on the thermostat as they should. However, when the water is set to ON, the radiators don't ever go cold, they just remain warm when the thermostat clicks off. Furthermore, when the heating is switched off at the control panel the rads remain warm and will only go cold if the water is switched off too. Basically, whenever the water is on, all the radiators go warm - not hot, just warm. Would I be right in suspecting a faulty control valve which is not closing fully and is letting some hot water through to the heating circuit?
Thanks for any help
Thanks for any help