I have a Gloworm Potterton boiler feeding a central heating system with a hot water tank. Now there is a fault .. the radiators work ok but I have no hot water. If I ONLY have the hot water on (CH off at the control unit), the radiators still get hot and can not be controlled by the room thermostat. I feels like the hot water is only getting to the radiators but not the hot water tank.
Reading similar posts on this forum it looks like a valve is stuck but I don't know what that valve would be called or what it looks like, or where it might be located. Any help/suggestions would be welcome.