2/19 | 21/08/04 16:41 | IMG_1156       [Thumbnail pictures missing down the left-hand side? If so, click here to display the page properly]

Mira Excell Thermostatic Cartridge. As you can just make out in the picture, the (hot) inlet strainer appears to be blocked with what I initially could only describe as 'black stuff'. I now know this to be ethylene propylene and was a result of the perished diverter-valve diaphragm in the boiler.