A thermostatic mixing valve maintains an elevated tank temperature while providing more tepid water for the taps. This ensures the tank is kept at a sufficiently hot temperature to prevent bacterial growth. It also provides a lower temperature for the hot water that comes from the tap. This helps with lowering the risk of accidental scalding.

Essentially, a thermostatic mixing valve functions by combining cold water with the hot water prior to it reaches your taps.  Below are some of the regulations of the thermostatic mixing valve Australian Standards:  

Thermostatic Mixing Valve Australian Standards

In Australia, tempering valve regulations are used to govern hot water temperature. The regulations dictate that there should be a minimum of 60 degrees Celsius in a hot water tank.  Additionally, the maximum temperature for hot water from the tap should be 50 degrees Celsius at any showerhead or personal hygiene tap.  

Based on Australian Standards, the maximum temperature for the hot water from the tap is 45 degrees Celsius for facilities like hospitals, nursing homes and schools. The valve must assist in meeting these various goals. It is necessary for the heater valve to prevent hazardous bacteria growth and scalding.

There are two conflicting requirements in the tempering valve regulations outlined by the PCA or Plumbing Code of Australia. To safeguard against Legionella bacteria growth, it is legally required that the temperature control valve be set at 60 degrees Celsius or higher. However, at this temperature, a severe burn could occur within 1 second.

The Code requires that the temperature for hot water from the tap should not surpass 50 degrees Celsius for personal hygiene purposes. For facilities like primary and secondary schools, early childhood centres and nursing homes, the maximum tap temperature should be 45 degrees Celsius.  

How Can Both Requirements Be Met?

Thermostatic Mixing Valve and Hot Water Tempering Valve Are Now Required

It is now required that all renovations or new constructions must have tempering valves installed.  Therefore, when an old system is being replaced, a tempering valve must be installed to lower the temperature of the water from the bathroom tap. 

Laundry and kitchen applications can circumvent the tempering valve, so the hot water can be directly used from a standard gas or electric hot water tank. Thermostatic mixing valves respond quicker to changes in pressure and temperature. They also typically restrict temperature variances output to ±1 percent.

Adjustment to Hot Water Tempering Valve 

Only a qualified and experienced plumber should adjust the hot water tempering valve. It is extremely important that the temperature adjustment is not attempted by the homeowner. The expert will use the knob to combine the hot water with the cold water. This will be done until he or she arrives at the required temperature of 50 degrees Celsius.

Before making any adjustment, the plumber will check to ensure the temperature of the tank is set to 60 degrees Celsius, the required minimum. For additional details, you can contact West End Plumbing WA – Licensed Perth Plumbers for Residential and Commercial Plumbing.