Roca WC Cisterns?

My Roca system is "Ghost FLiushing". i.e. every 30 seconds or so it executes a mini-flush all of it's own accord. How do I fix it?|||Sounds like it's a problem with the float valve/ball valve not shutting off properly, causing the water level to rise until the flush valve triggers a flush to stop your cistern from overflowing. You should be able to buy a generic valve from any basic DIY store, or you could try getting in contact with Roca's customer service to get them to send you one out for your specific cistern. Then it's just a case of shutting off the water supply to the cistern and switching them out.