If my shower mixer bath is left in the cold position i cant get any hot water downstairs. the cold water is mains fed, and my boiler condenseing(worcester bosch 28i) is only 2 years old. Also if i switch the shower bath mixer to cold it just cools and the boiler still heats the water. if left in the warm to hot position the rest of the taps in both the bathroom and kitchen run fine, hot and cold. can i fit a one way valve to either the side of the mixer, or so i need to fit some sort of pressure reducer for the cold water.
Any help please