What temperature should hot water be stored at?

Defra guidance states that hot water should be stored at a temperature of not less than 60ºC and distributed at a temperature of not less than 55ºC in order to prevent Legionella growth. This water distribution temperature may not be achievable where hot water is provided by instantaneous or combination boilers.

Where practicable, the hot water temperature at the tap should reach at least 50ºC within 30 seconds of fully opening it. Thermostatic mixer valves (TMVs) should be installed near outlets where there is a risk of scalding. This criteria may not be achievable where hot water is provided by instantaneous or combination boilers.