I don't have a key not sure if I even need one? but pressure needle really low. top floor rads only part warm. dare not bleed anymore as not enough pressure in the system. can anyone help a 30 something female who is freezing. It is the 28si.
thanks for reading
Lisa

Lisa, January 2012

If you don't have a silver filling loop on the the pipework then on the 28si it will require a small white key to charge it up(usually left by the installer). The charge point is underneath next to the little white spindle used to let the water in.
hope this is of some help

Dave coleman, January 2012

you use the filling loop under the boiler to top the system to about 1.1 bar.then bleed rads.Key required.once finished top boiler back to 1.1 bar

A1, January 2012