I had the same problem in my mira showers (2) too till I changed the cartridges Ordered stright from Mira www. mirashowers.com. The unit was quite expensive approx �115 from memory You need to establish which model you got before you place the order, However, the reception was very helpful and I got the right cartridge 1st time. Came by post within a couple of days. To change the cartridge was very stright forward all you need is a screw driver. I hope this helps