Can you help please troops , I cant even bang a nail in straight. My condensing boiler central heating system keeps getting air in it . I have to bleed the thing every 5/ 6 weeks. It's always the upstairs rads that get the air in . My boiler is only 3 years old and has just been fully serviced and passed muster. I have a header tank up in the loft cavity which seems to be full of water so I should say it is ok ? I have followed professional advice when bleeding the rads . Some one told me to up the pressure in my boiler through two taps and a silver metal webbed tubing but my condensing boiler does not have such an attachment . Any one out there can assist me please ??