relight my 230 rsf worcester combi?

there's a sequence to the boiler lighting which you can follow to locate the fault when you switch the boiler on the the pump should start which starts the fan the fan pressure switch operates which causes the spark at the burner (this is a clicking sound ) the spark is detected which opens the gas valve a comman problem is the fan pressure switch the fan runs but there is no spark try tapping the switch

brian
June 2010