Hi. I have the same problem. The thing is - it’s a totally new system. I changed over from oil to gas and have all new system including pipe work and radiators. Old system stripped out. But from a few weeks after install, a few of the upstairs radiators need bleeding ever few weeks - probably every week if I checked. Usually the same 3 radiators upstairs but there’s 2 others which never need bleeding. They’re probably on a different set of pipework. So definitely not corrosion or gas or sludge buildup. I’ve checked on the internet and the only thing I can see that it might be, is that the pump is drawing air in. What I can’t understand is if there is a leak, why isn’t there water at the leak. Some say the leak isn’t big enough to let water out, but it is just enough to draw air in. The solution apparantly is to drain the whole system, and pressurise it to find out where the leak is. This involved some sort of liquid to detect the leak? Any info on how to do this and what is required or is it a specialised job. For info only, the system was installed by a large company who only installs central heating system and not done by a diy crew. Thanks ahead for any info.
