Existing bath and shower installations should be upgraded to provide protection from scalding hot water.
The British Burns Association recommends 37 to 37.5 degrees C as a comfortable bathing temperature for children. In premises covered by the Care Standards Act 2000, the maximum water outlet temperature is 43 degrees C.
All existing bath and shower installations in public, residential and commercial premises should be upgraded to provide the same protection from injurious scalding hot water as is now necessary in new homes, says Honeywell. This is easy to achieve by fitting fail safe thermostatic mixing valves (TMVs) in the supplies to hot water outlets.
An amendment to Part G of the Building Regulations requires housebuilders to install TMVs on baths and showers from October 2009. Facilities managers can easily protect existing installations by fitting Honeywell TMVs in the hot and cold water supplies to baths, showers and basins. They ensure a constant safe temperature at the point of delivery by blending hot and cold supplies to provide a uniform, safe pre-set temperature.
In healthcare, thermostatic mixing valves certified to Buildcert TMV3, such as Honeywell TM200VP, must be fitted. Valves to the domestic TMV2 standard, such as Honeywell TM300, are acceptable for most other premises but a risk assessment should be carried out to determine if the facilities are used by vulnerable people, such as the elderly, young children or the mentally or physically disabled. If so, TMV3 valves should be installed to provide the higher safety level.
Both Honeywell TMV models employ a highly sensitive wax element which controls the hot and cold water inlets to provide a safe uniform temperature between 38 and 46 degrees C, as set by the installer. In addition, it ensures safety by cutting off the hot water inlet automatically if the cold supply fails.
Honeywell explains that the BuildCert TMV scheme recommends the following maximum hot water temperatures for use in all premises: 46 degrees C for bath fill; 41 degrees for showers and washbasins; and 38 degrees C for bidets. However, while 46 degrees C is the maximum temperature for water from the bath hot tap, it takes into account the margin of error inherent in TMV valves and temperature loss in metal baths, especially in cold bathrooms. It is not a safe bathing temperature for adults or children.
