Help! Installed new closed cistern toilet with push button and flushes fine. Then after about three minutes the inlet valve begins to run water again and there's an horrible screeching noise a minute or so later. I have adjusted the level but still leaks noisily after a while. Could it be to do with something called a filter restricter - it came in the pack but I didnt bother fitting it because never needed on my previous toilet?
I'd appreciate any help. Thanks...