My heating system has been driving me crazy for a few years. It's a fully pumped vented system with HW priority. After we'd been here for a couple of years I had to replace the pump and during the drain-down noticed the water was black, like ink......so I flushed it all out until it ran clear, replaced pump, refilled, added inhibitor etc and all seemed well.......I say 'seemed' cos after I while I noticed the downstairs rads (only 2) wern't getting very hot. Anyway, (I'm cutting a long story short, believe me!) if I turn off the upstairs rads, the downstairs ones get hot, but as soon as I crack open the upstairs ones, downstairs go tepid. I lifted some floorboards and found that all the upstairs rads feed directly off 22mm pipes, but the feed to the downstairs rads is tee'd off one of the bedroom rads 15mm pipes!.......to me this doesn't feel right, as there are 3 rads all trying to be supplied through a pair of 15mm pipes. I also tested for magnetite using a strong magnet and it 'pulls' in a few places, noticably on the branch going downstairs. I put some sentinel x400 in over two weeks ago but the water is still clean in the system. Is it possible for the magnetite to go hard and resist the cleaning sloution?
I intend (when the weather gets warm) to redo the pipework and extend the 22mm feed so that the downstairs rads get fed off that, and replace the pipes that are 'magnetic'..........and also to run 22mm pipes into antoher bedroom so I can drop down to the living room and fit a rad there. Does this sound ok, or have I missed anything out.......your comments and/or suggestions would be very welcome....thankyou :wink: