Now I have the valves open and I have ensured the radiators are all bled. Some heat is now reaching the radiators downstairs (remembering that one of them downstairs has always remained hot/working) but they just won't get hot, the pipes leading to them eventually get hot and some heat passes to...
My pressure relief valve recently broke and for a while we managed to live with it but the radiators downstairs remained cold except for some heat occasionally when I adjusted the in and out valves. I have now replaced the broken pressure relief valve and heat is now reaching downstairs although...