TMV Servicing

Health and Safety Executive ACOP and Guidance L8 states:

“Temperature regime:-This is the traditional approach to legionella control. It is recommended that hot water should be stored at 60oC and distributed so that it reaches a temperature of 50oC within 1 minute at outlets. Care is needed to avoid much higher temperatures because of the risk of scalding. At 50oC the risk of scalding is small for most people but the risk increases rapidly with higher temperatures and for longer exposure times. However the risk , particularly to young children, or the handicapped or elderly, and to those with sensory loss will be greater. Where a significant scalding risk has been identified , the use of TMVs on baths and showers should be considered to reduce temperature. These need to be placed as close to the point of use as possible”

“Users should refer to the manufacturers’ operating instructions to ensure these devices are working safely and correctly”

Where temperature is the primary control measure to control the multiplication of Legionella Bacteria and the systems are utilised by those at risk from scalding the installation of TMVs must be considered.

Where installed, TMVs will require regular servicing, generally twice per year. Where the valves installed are of the “fail safe” type (ie the valve will shut down if either the hot of cold water supply fails) then a fail safe test should be carried out to check the valve performance.

IWS water hygiene operatives are trained in the fail safe testing and servicing of all makes of TMVs. The TMVs can be fail safe tested and serviced and calibrated at agreed frequencies dependant on the valve manufacturers recommendation and the hardness of the water (scale formation is a primary consideration when deciding on service frequency).

The valve asset number, fail safe test result and service/calibration details are recorded by IWS operatives on their PDA and the data uploaded via GPRS mobile communications to the IWS Online Report Tracker system; the data is then visible by the client via the IWS web site login to ORT.

Valves that do not “fail safe” or cannot be calibrated are isolated and the client notified immediately.

IWS offer TMV fail safe testing calibration and servicing utilising trained IWS operatives working from seven regional service centres across the country.