Hi, I have a three floor detached house. My central heating system consists of separate up and down systems so two pumps. The system was working fine last week but then I got a leak from a downstairs rad since then I can turn the upstairs on and it will get hot. If I turn it off then turn downstairs on it get hot. If I turn both on together the only thing that gets hot is the upstairs towel rail. Has anybody got any idea what's going on.
Thanks.
Thanks.