broken toilet cistern - Page 2

Hi

Had a similar problem after using cleaning blocks inside cistern. It turned out to be residue from the block was preventing the big washer from seating properly 

Remove the top cover

Turn off water supply to the toilet

Empty the cistern

Clean all around the big washer, both top and underside

Refit the lid, turn on water and try again

hope this helps. If that doesn’t do the trick you probably do need a new unit. You can get them from most hardware shops. 

Cheers

Neil

its not sealing properly at the bottom . probably need a new one ,they are quite simple to fit.

You tube very informative:Fix Constantly Running Dual Flush Toilet Cistern By Replacing The Flush Valve Washer.Problem could be the washer at the bottom of the dual fill - the washer has probably accumulated limescale etc - just needs cleaning or replacing.