While you wait for answers, we may have found some information which could help you.
Click here for Flush Cistern FlushesSlow fill of toilet cistern?
Grohe push button toilet attached to saniflow ?
Grohe 42181 toilet filler valve leaking?
how to take unit apart?
Short burst of water entering cistern ?
The push button on my Grohe Adagio stopped flushing ?