Can you hear the pump working? unscrew the silver screw in the front face of the pump (a little water will dribble out) look inside you should be able to see the shaft inside rotating replace screw afterwards
even if the pump is rotating it can be that the impellor (fan) has dropped off of the motor shaft so nothing is happening - are the pipes to & from the boiler getting hot? are all the Radiator valves open? are the pump valves open?
However it does sound like the pump is at fault!
www.elanar.co.uk, March 2011
