switch off at mains, carefuly remove front of shower box, taking care to remember your settings, to make things easy just centralise controls, if youre unsure take a photo via camera, or phone, before you disassemble and during procedure. the water is flowing thru a p.r.v. thats a pressure release valve. whitch usually is blown if flow is too high, this is simply repaired by either locating small plastic ball thats been blown out and should still be in tube, simply push ball back in place, not too much force, but a gentle pop should do , ,reassemble your shower ,turn back on water supply, switch on power.
james, May 2009