Find the mains cold water pipe which supplies the boiler. Along this pipe there will be a joint and from this one pipe [usually a flexible silver braided] will go to a central heating pipe [22mm] Between the mains and the 22mm pipe there will be a black thumb turn tap or silvery service valve [operated by a screwdriver the slot in the valve which indicates closed when at 90 degrees to the line of the pipe and open [water goes in] when inline with the pipe. Open this valve tap until the water pressure [observe pressure gauge] reaches about 1-2 bar.
Don't forget to bleed the rad after and maybe renew pressure
A later model may be supplied with an insert filler which inserts and turns 90 degrees to allow the filling tap to be operated. Both these are under the boiler
crumple, August 2010
