Added 2 new radiators upstairs and now 1 downstairs is cold

Hi

I have removed one radiator form a bathroom upstairs and used the feed and flow from it to add 2 new rads in an extension, when i turned the system back and bled air from every rad every thing is ok apart from one radiator down stairs that is now not working (completely cold)
the pump was upgraded to accommodate the new rads as i've one more to add

another thing is can pipes touch ie the main and flow pipe as the room to run pipes was limited, i will lag with fibre wool

thanks in advance

yes pipes are o.k touching.try turning a couple of rads off that are working and if the problem rads get warm your system could need balancing,if not you could have air trapped in the pipework somewhere.

how do you clear an air blockage?