Thanks for the reply.
Sorry my description ain't that clear I'm not a plumber and not used to this type of system.
Basically when heating is on i can hear what sounds like running water in the hot water cylinder.
When I put the heating off the f/e tank then starts supplying water to the...
Hi, recently moved house and it has an open vented system with f/e tank in loft. Had an issue with the f/e tank overflowing with hot water and cold spots on rads. Drained system down and added sentinel X400, overflow seems to have stopped and radiators are becoming a bit better than they where...