The easiest way to prevent burns from hot tap water is to turn down the setting on your hot water heater to 49°C (120° F). Do this only if you can easily see the thermostat dial on the outside of the tank.
Note: A third degree burn (characterized by blistering, intense pain and permanent tissue damage) will occur in children in only 5 seconds when water temperature is 60°C (140°F). At 55°C (130°F), a third degree burn will occur in 15 seconds, while the time to produce a third degree burn extends to at least 5 minutes when water temperature is 49°C (120°F). Ostrow LB, Bongard FS, Sacks ST, McGuire A, Trunkey DD. Major burns resulting from scalds: The California burn registry experience. JBCR 1985; 6 (4): 350-352.
If you choose this option, there are some important things you should know:
If anyone living in your home has a long term or serious illness, check with your doctor before turning down your water heater. DO NOT lower the temperature of your water heater if anyone in your home has a weakened immune system, including the elderly, those who have chronic obstructive pulmonary disease, HIV/AIDS, an organ transplant, cancer or is taking medicine that suppresses the immune system.
People with these conditions are more at risk for legionnaires' disease, a type of severe pneumonia.
Read the manual for your water heater before changing the setting on the thermostat dial. If you do not have a manual, contact the company that made the water heater. Their number should be posted on the heater. If you rent your water heater, contact the rental company.
Devices called mixing valves or tempering valves can be installed in the plumbing pipes at various places. These valves control the temperature of the water before it leaves your taps. Inside your water heater, the temperature can be scalding hot, but the valve will mix in cooler water if needed, to ensure that water at the tap is no hotter than 49° C.
Talk to a qualified plumber or the rental company for your water heater for proper installation of mixing valves.
There are three ways you can use mixing valves:
If you do not have access to your water heater:
Turning down the thermostat of large water heaters in multi-unit buildings is NOT recommended. Harmful bacteria can grow in large water heaters set too low. Also, there may not be enough hot water for everyone in the building.
If you live in an apartment or multi-unit building and do not have access to your hot water heater:
Ask your landlord or property manager to make sure that the hot water at your taps is no hotter than 49° C (120° F). One option is to install mixing valve(s) in the hot water pipes so that the hot water is a safer temperature everywhere in your apartment. An alternative is to install a mixing valve at each of the taps in your kitchen and bathroom.
If you cannot get mixing valves installed in your hot water pipes, you can use other devices to help protect your child from tap water scalds.
Some other devices available include:
'Anti-scald' or 'shut-off' devices: These are products that attach to the faucet or tap. Some models actually replace the faucet. If the water gets too hot, these devices slow down the water to a trickle. You can restart the water by mixing more cold water into the tap.
Anti-scald devices are available in safety specialty shops, some hardware stores and some children's product stores. Not all models fit on all kinds of taps, however, and although these products are promoted as "do it yourself" items, they may require adapters or the help of a plumber to install them.
Tap guards: A tap guard blocks your child's access to the hot water tap. These can be found in many home improvement and child safety stores.