I have a Grohmaster Grohsafe EV 35 237 shower which suddenly will not work with hot water. All other taps in the house work fine just not the shower. I have tried bleeding the system to no avail. Any ideas?

Shut the water off to the valve, (I have put up a image to help you) and open up the valve. Remove the cartridge and check and clean the inlet ports. Now turn the hot water on for a bit to flush out the supply. You should see a strong stream when you do this. If not click on back and tell me about it. Reassemble and test. Better now? Good luck, Tom