A normal mixer tap is not necessarily a thermostatic valve. Check the installed product and specification before deciding which tests or replacement parts are appropriate.
How does it fit with water hygiene?
Consider scald protection and legionella control together. A TMV mixes water near use while the upstream supplies follow their intended control arrangements. Turning down the whole hot-water system for one outlet can conflict with those arrangements.
The mixed temperature at the tap does not show the upstream hot-water condition. Monitor the right points separately. The installation should avoid unnecessary mixed-water pipe lengths and allow access for maintenance.
HSE's hot and cold water guidance explains the connection between hygiene, temperature control and scalding risk. Selection and management must account for vulnerable users and any particular requirements of the premises.
What should an owner or manager record?
Keep the valve’s make, model, position, outlet and installation information. Link its service results and unfinished work to that record. Where several valves are fitted, identify each instead of recording only that the bathrooms were checked.
A hidden valve needs usable access for servicing. Agree testing, cleaning or parts work as appropriate, including the result and any restriction on the outlet. Plan access without unnecessary damage to unrelated finishes.
Frequently asked questions
Does a TMV prevent legionella growth?
No. Its main role concerns mixed-water temperature, not disinfection. The property still needs risk assessment and controls for storage, distribution, use and monitoring.
Can every TMV be used in a care environment?
No. The product must suit the setting and assessed risk, including vulnerable users. Being able to connect it to the pipes is not enough evidence.
Does a steady temperature mean the valve has passed its service?
A single reading does not complete the required tests and servicing. Ask what was checked, how and against which criteria. Unexpected changes or poor performance need investigation.
Related reading and support
Read how often TMVs should be serviced and what a legionella risk assessment covers. See TMV servicing and testing and maintenance, or discuss an outlet or system with the product details and symptoms.
