Firstly I'm no plumber or know YOUR boiler.
On mine under the boiler there are probably about 5 pipes. TWO of them are linked by washing machine type taps or isolating valves. You may see the linkage from 1 to other by a flexible pipe (silver?).
When they are opened water will go from the mains into your system (replacing any leakage - or in your case - air). WATCH THE PRESSURE GUAGE AT THIS POINT!!!...and turn off when it reaches 1 bar. Job done MAYBE.
However it MAY need to be reset if the pressure has dropped VERY low. Let me know how it goes on.
Steve, November 2006
