I often hear from Sydney home owners that their hot water is not hot enough. Don’t get me wrong, I love a steaming hot shower like the rest of us but legal temperatures are something to take very seriously.  A large part of your family’s safety revolves around hot water within your home. It is critical to identify the potential hot water hazards in your home.


If the hot water within your home is too hot, you leave your family at risk of scalding. Scalding is serious and the burns associated can cause permanent damage or even permanent disabilities.

Hot water can also cause shock and, in some cases, lead to death.

So hot water temperature control is extremely important.

Did You Know

  • At 60 ºC, it takes one second for hot water to cause third-degree burns.
  • At 55 ºC, it takes 10 seconds for hot water to cause third-degree burns.
  • At 50 ºC, it takes five minutes for hot water to cause third-degree burns.

Remember that the maximum bathing temperature recommended for young children is between 37 ºC and 38 ºC, so cold water still needs to be mixed with water from the hot tap.

How hot can I have my hot water?

Pre-1998 storage hot water heaters were flowing out with hot water temperatures in excess of 70 ºC , which was great for those steamy showers but also extremely dangerous.

In 1998, Australian Plumbing Standards introduced a law that stated the hot water temperature had to be regulated to 50 ºC within the family home. It is illegal not have a tempering valve fitted and it is the plumbers legal obligation to install one when fitting a new hot water heater.

In health care facilities such as childcare, retirement homes, and hospitals, the law asks us to go a little further and install a serviceable valve called a TMV (which stands for Thermostatic Mixing Valve.)

In these facilities, the water cannot not exceed 42.5ºC. These valves are required to be tested once a year by a licensed plumber and Sydney water will required proof of testing, as well as reminding you of your obligation to test the valves.

Things to check for hot water safety

If what you have read above has worried you, don’t be alarmed, there are things you can do to help prevent injury within your home.

Simply purchase a thermometer, or you may already have one in the kitchen, and test your hot water in your bathroom. If the temperature exceeds 50 ºC, action is required.  You will need to contact your local plumber to install a tempering valve for your whole home or just for the hot water within your bathrooms.

Please be mindful that your tempering valve has a lifespan of 5 years, so ask the plumber to date when it was installed on your heater along with the temperature it is set at.

You should test the hot water yearly at the closest point for the correct temperature. If it’s too hot, the tempering valve has failed and requires adjusting. Or, if it’s older than 5 years, it requires to replacement.