I've a Gainsborough 8.5 and have had about a dozen engineer call outs to it under warranty. I am now an expert in them! I would say you have either the blocked filter issue or your pressure release valve has popped. This is a little rubber bead along the water flow pipe at the bottom left. It pops out in the event of pressure build up like a kinked shower pipe. It normally results in leakage from behind the unit but if yours is siliconed to the wall you may not see the leakage. The rubber ball can be reinserted easily. Hope helpful.
John, September 2007
sounds like you have a blocked filter gauze in the mains feed pipe. which is where the pipe joins the shower inside
