A Thermostatic Mixing Valve (TMV) is a safe way to ensure a constant delivery of hot water which can be set by the user to ensure comfort and safety. Thermostatic Mixing Valves are commonly found in many different applications including Domestic Dwellings, Offices, Care Homes, Hospitals and Schools just to mention a few.
A Thermostatic Mixing Valve will blend hot and cold water to ensure water is supplied at the right temperature to each outlet. With a TMV in place you can safely store water at over 60 DegC which will kill almost all traces of Legionella and still ensure that the water is safe for use. Most Thermostatic Mixing Valves operate using a wax capsule which also acts as a safety feature if cold water supply should be lost, if a total loss of cold water should occur the valve will shut all supply to the hot taps.
Dependent on the application and the users you will need to use a different type of Thermostatic Mixing Valve. Mixing Valves Will conform to a TMV Rating, usually in the United Kingdom they will conform to either TMV2 or TMV3 with DO8 being recognised as the standards set by Hospitals.
TMV3 Valves are tested by a third party who is accredited by Buildcert. TMV3 Valves are suitable for use in High Risk Commercial Healthcare applications and are based on the NHS DO8 Scheme. If the Thermostatic Mixing Valve is approved at TMV3 this will be valid for 5 years and at the end of this period the manufacturer must apply for compliance again.
TMV2 was introduced in November 2003, Valves which conform to TMV2 are more specifically designed for the domestic market. With changes to Part G Building Regulations coming ever nearer this will now require you to install a TMV2 to all Baths in new homes. This has been in Force in Scotland since 2006 requiring a TMV2 Thermostatic Mixing Valve to be fitted to all Baths and Bidets.
There are many organizations and charities which support the work of Thermostatic Mixing Valves and recognise the necessity of them. Campaigns such as Hot Water Burns Like Fire help to promote the awareness through organisations such as the Child Burns Trust (CBT) and Royal Society For The Prevention of Accidents (RoSPA). And with new building regulations coming into force we will all be required to install at least a TMV2 rated Thermostatic Mixing Valve to all outlets in new bathrooms that require planning permission.
You can find below a TMV Selector Chart should you need any assistance choosing which TMV best suits your needs.