To comply with (a) above you must install a thermostatic mixing valve adjusted to an outlet temperature of 45°C. To comply with (b) above you must install a thermostatic mixing valve, or a tempering valve or a pre-set water heater permanently disabled at 50°C.

The Plumbing Code of Australia states that stored hot water must be maintained at a temperature which prevents the growth of Legionella and other bacteria. To achieve this most hot water storage tanks are set to 60°C+. This includes solar, electric, gas and heat pump hot water systems with storage tanks.

A thermostatic mixing valve is a device which blends hot and cold water to provide your home with a reliable consistent hot water temperature at the hot water tap. The delivery temperature is usually set by your plumber during the installation. A thermal-sensitive element within the valve expands and contracts in response to changes in the temperature of incoming hot and cold water to maintain the required delivery temperature.

The National Plumbing and Drainage Standard AS/NZS 3500.4: 2003 states - All new heated water installations shall deliver heated water not exceeding -

This system protects residents from illness caused by bacteria, such as Legionnaires disease, as well as significantly reducing scalding risk.

Tempering valves and TMV's get mixed up quite a bit so we've put together some facts to help our customers understand what they are and why they should have one fitted in their home's plumbing system.

However, if the water is delivered to the taps around your home at this temperature there is a high risk of scalding, which is why tempering valves are needed. The tempering valve mixes the hot water from the storage tank with cold to reduce the temperature to a much safer 50°C before it reaches the outlets.

Tempering valves are required for all new builds, bathroom and ensuite renovations, or when a replacement hot water system and piping installation is carried out. They are not mandatory for hot water system upgrades or replacements alone, however, our plumbing team recommend fitting a tempering valve during system installation to provide the best protection for your family and visitors.

A tempering valve is a 3-way mixing valve which is temperature actuated and used to temper a heated water supply by mixing the heated water with cold to feed heated water at a reduced temperature to the taps around your home.

Thermostatic mixing valves respond faster to temperature and pressure variations than tempering valves. Regular servicing is needed to ensure reliability and complete protection.