montasser charni
Hi Javed Before making any pre-diagnostics we need to know what hot water system supplying your shower ,example is it a combination boiler or a conventional gravity hot water cylinder ? Let's say the latter! Then it could be 1) an air lock .2) low pressure Also it could a pressure booster pump failure if you'have one . These are few causes to begin with . I hope these few answers can help you at least determine the fault . You can get back to us if further help is needed . Regards