I have a bristan shower which is approx. 10 years old, hot water is go

William Keogh

Sanjay, I would imagine this is either because the Shower Filters are blocked or more likely the Thermostat has gone (could be from scale,age, etc.). If the Thermostat has gone I would recommend you get a Shower Valve and not repair it. Bill Pipe Dreams Plumbing Services, Bournemouth, Dorset