I have a gravity fed system and have a problem with the hot water flowing back up the cold water feed into the header tank. This warms the water in the tank and it runs out of the overflow.
If I close the cold water feed to the cylinder the warm water flows up the vent pipe from the top of the cylinder and into the header tank which overflows.
I have changed the hot water cylinder as I thought there might be a leak from the central heating coil into the cylinder itself. All parts new.
I am at my wits end as we need the heating on but there is a steady flow of heated water down the drain!
Help!
