Hi Mike
I have just had the same problem. I removed the thermostatic cartidge (easy job, 8 srews), to find the spiral material had deteriorated. I reassembled and then found the shower worked fine. The cartrige will need replacing (£105!) & I will replace the rubber gasket as well. What I still cant figure is why the cold water stopped flowing in the first place as there was no blockage. Still an easy (if ultimately expensive) fix
paul
Paul, December 2007