Hi, I am a complete novice when it come to DIY plumbing and looking for any help in troubleshooting this pressure issue. I have two Mira Excel showers that have both lost pressure over the last month but at different times. I have cleaned the showerheads and hoses and I have had a plumber round who has replaced the cartridge and back plate on one of the showers (en suite) and whilst the pressure is better it is still not as good as it used to be. Since this was "fixed" last week, the pressure has now dropped in the other shower. I have an unvented mains pressure system with a Heatrae Sadia Megaflo cylinder next to the Worcester Oil boiler in the garage. Any ideas as to what might be causing this issue?