check the float isn't stuck,remove cistern lid,if it doesn't just lift off then unscrew the whole push button if it's a single flush and if it's a 2 button/dual flush carefully ease up the larger button with a flat screwdriver then remove smaller button.There should be a plastic screw,undo screw and this will allow you to remove lid.check float (usually on right hand side) moves freely up and down.If so maybe the flow restrictor in the water inlet is blocked but this can be removed by closing the service valve at cistern water supply and disconnecting the pipe where it screws onto plastic thread,inside there'll be a little plastic peg which you'll be able to remove with small pliers,clean and replace but make sure washer in supply pipe is not damaged and do not overtighten.
steeveepee, March 2010
