Safer Hot Water
Hot-water temperatures in excess of 65°C can cause a third-degree burn in under a second. But at 50°C, a third-degree burn takes five minutes.
Many states now have mandatory Australian Standard guidelines for the supply of hot water to bathrooms and other personal hygiene areas in the home, and other states are considering it. Newly installed hot water systems must be regulated so that the hot-water temperature to these areas doesnt exceed 50°C. In early childhood centres, schools and nursing homes the maximum permitted temperature is 45°C.
The onus is on the plumber to fit equipment that meets these requirements -- there are several options, depending on your situation.
The easiest solution is to install a tempering valve between the cold inlet and hot outlet pipes of the hot-water system. The plumber adjusts it to mix in the appropriate amount of cold water so that the water temperature is always safe. To maintain a supply of hot enough water to the kitchen and laundry, the tempering valve can be positioned so that it only regulates the hot water going to the bathroom.
They cost around $100-$150 and installation costs about $100-$200. Howe'ver, because tempering valves arent accurate enough when 45°C is the maximum permitted temperature, in that situation a thermostatic valve is needed, which costs around $500.
Simply lowering the temperature of water in the hot-water tank to 50°C is not an acceptable solution because hot-water systems must store water to at least 60°C to inhibit growth of legionella bacteria.
If youre installing a new hot-water system, speak to your plumber about the best solution for your needs, or contact your health department for further advice.
If you have small children or elderly people in your home, you could consider installing a tempering valve or an outlet shut-off valve in your existing system. These reduce the flow of water to a trickle if its too hot; when cold water is added and the temperature becomes safe, the valve opens and the flow returns to normal. They cost around $50 and can be installed DIY (although in some states this is illegal -- check with your local authority).
❊ Web Links ❊
➼ Safer Hot Water
❊ Be Social ❊
➼ Content Editor