Temperature of hot water to showers

Cornflake59

We are having a pressurized gas heating system installed in our Victorian house. We have someone writing the building regs who is saying the water temperature cannot go beyond 48. Please comment and advise. Really paranoid. 

Gerry1

• Hot water storage cylinders (calorifiers) should store water at 60°C or higher
• Hot water should be distributed at 50°C or higher

https://www.hse.gov.uk/healthservices/legionella.htm

Owain_Moneysaver

But then use a thermostatic shower mixer so the temp at the outlet does not exceed a safe level. 

Talldave

The 48C comes from requirement G3 (4) of Part G of Schedule 1 to the Building Regulations 2010. As @Owain_Moneysaver points out you achieve this using a thermostatic mixer to reduce the temperature from the 50-60C tank temperature.