Enquire Now

TMV servicing

AEC will carry out your Thermostatic mixer valve (TMV) servicing on an annual or six monthly basis (the service frequency varies according to the TMV type). These are typically installed to prevent scald risk and are commonly found in Healthcare premises and sheltered housing schemes. AEC’s water hygienists are DBS checked to work in industry sectors with young or vulnerable people (such as hospitals, sheltered accommodation and schools).

AEC will carry out your annual Thermostatic mixer valve (TMV) servicing on an annual basis. We have water hygienists DBS checked to work in industry sectors with young or vulnerable people (such as hospitals, sheltered accommodation and schools).


A thermostatic mixer valve (TMV) is a safety device which blends hot and cold water to pride an outlet with blended water at a set temperature. Typically for basins, this is in the range 39°C to 43°C.

TMVs are generally installed for safety reasons and to prevent scalding. They therefore require periodic testing and servicing to ensure that they are working effectively. TMVs can fail and in the worst cases can allow hot water through to the tap at its maximum temperature or could allow hot/cold water to mix in the supply pipework and reach temperature where the legionella bacteria can multiply.

Legionella is a bacterium that can cause Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever. People contract Legionnaires’ disease by inhaling small droplets of water (aerosols), suspended in the air, containing the bacteria.

Legionella bacteria are widespread in natural water systems, such as rivers and ponds. However, the conditions are rarely right for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth such as cooling towers, evaporative condensers, hot and cold-water systems and spa pools used in all sorts of premises (work and domestic).

Legionella bacteria can cause Legionnaires’ disease, a potentially fatal type of pneumonia. It can also lead to other similar, but less serious conditions, of Pontiac fever and Lochgoilhead fever. Any water system has the potential to become a hazard to health, from a change in environmental conditions on site, an unnoticed system malfunction or a physical change in the system and use of the premises.

A  legionella risk assessment involves a full inspection and assessment of the configuration, construction and condition of your water system. The purpose is to identify whether  the equipment associated with the system such as pumps, heat exchangers, showers etc, and its constituent part are  likely to create a risk from exposure to legionella.


A Water Management Policy, Plan and Procedure Document is designed to help your organisation set clear goals for water management.   It is an auditable document that details clearly how you will manage the risks and track any remedial actions and on-going monitoring of the water systems.  Your management plan should be reviewed annually and is an essential document to fulfil the statutory obligations.

Our clients benefit from AEC’s online portal.  Available 24/7 all your records are contained in an easy-to-use management system.  It’s a fast interactive system providing secure access to all reports and data to view  at any time.  View AEC’s Client Portal here.

The Duty Holder is the employer or person in control of the premises.

The Duty Holder is required to manage the risk from legionella bacteria by:

  1. Identifying and assessing sources of risk
  2. Managing any risks
  3. Preventing and controlling any risks
  4. Keeping and maintaining correct records
  5. Carrying out any other duties you may have.

Duties under the Health and Safety at Work etc Act 1974 (HSWA) extend to risks from legionella bacteria, which may arise from work activities. More specifically, the Control of Substances Hazardous to Health Regulations 2002 (COSHH) provide a framework of actions designed to assess, prevent or control the risk from bacteria like Legionella and take suitable precautions.  The Approved Code of Practice: Legionnaires’ disease: The control of Legionella bacteria in water systems (L8) contains practical guidance on how to manage and control the risks in your system.

The Legionella Control Association (LCA) is a membership organisation for providers of services and products concerned with the control of legionella bacteria in water systems.  A valid registration with the LCA is evidence that the Member has an appropriate management system in place to comply with the LCA Member Commitments and that these are regularly audited by the LCA.


AEC are the pure definition of discretional effort. There are too many examples of how they have  gone beyond what the client stipulated to assist the university meet and exceed statutory compliance.

Andrew Welton, Facilities Safety & Compliance Manager, Lancaster University.

The Canal & River Trust are delighted to be working in partnership with AEC, a consultancy firm with such vast experience within the legionella and water hygiene industry.  AEC’S expertise and professionalism so far has been a credit to all those involved, and we are looking forward to working closely together to ensure our network of buildings and moorings sites maintain and achieve the highest levels of compliance.”

Dominic McCann, The Canal & River Trust’s Senior Building Surveyor

* AEC is UKAS accredited for asbestos surveys, air testing and bulk sample analysis only.

Contact our water hygiene specialists

Contact Us