While you wait for answers, we may have found some information which could help you.
Click here for Grohe Concealed CisternHave I been charged way to much for having a loo mended?
grohe toilet cistern leasks ?
Short burst of water entering cistern ?
how do I change the bellows in the push button unit for the grohe cistern?
Replacement of bellows in Grohe air button?
Slow fill of toilet cistern?