Dual flush cistern overflow

If it’s overflowing the seal on the inlet is leaking, if you have adjusted the float then it must be the seal itself.
They are available at the big green shed or other good hardware stores or plumbing supply.

Originally Posted by neilb

The dual flush toilet cistern is playing up. It was overflowing on both half and full flushes . Today I adjusted the float mechanism , i moved the main setting from 18 down to 16 , flushed it a few times to check it and it worked ok on both buttons. All afternoon it was good. Now 6PM, it is overflowing again only on full flush. The half flush fills to about 20mm below the top of the overflow pipe which is ok but the full flush goes over. How do i fix it ? Thanks.

From my experience it is not worth replacing the inlet washer, replace the inlet valve with a fluidmaster around $20.
And replace the flush/outlet washer at the same time, and go to a plumbing supplies for the correct one, and I don't buy the packaged fixatap stuff.