The HSE's ACOP L8, HSG 274 and HTM 04-01 give guidance on the effective measures required to reduce the potential risk of Legionella. All fixtures, fittings and valves have a purpose, for example, thermostatic mixing valves (TMV) mix hot & cold water to reduce the hot water temperature to a safe temperature to wash and bathe in. However, these "safe" water temperatures fall within the temperature range that could promote bacterial growth. A failing mixing valve can also increase the risk of scalding.
Accreditations, Qualifications and Memberships
Water Wise are approved by Trading Standards and certified by Trust Mark who are a Government endorsed competent person scheme. Our assessors are also members of the CIPHE, recognised by DEFRA and the Secretary of State as Approved Contractor Persons under the Water Supply Regulations and are Water Safe registered as required by the Department of Health's HTM 04-01.
Thermostatic Mixing Valves
Advice is often given that TMV valves need regular maintenance. This is not true. TMV valves need to be regularly inspected (called a failsafe check).
A failsafe check is designed to ensure that the TMV valve is in working order and identifies any maintenance requirements. A failsafe check is an additional measure to any temperature monitoring requirement for your TMV valves. Only if the TMV valve fails the failsafe check do you need to maintain or replace the valve.
The requirements for TMV inspection and maintenance are found in the HSE's ACOP L8, HSG 274 part 2 and Specification D-08 which is a supplement to HTM 04-01.