Domestic Hot Water Storage Temperature

Keep tank and faucet water temperatures at safe levels.

All water heaters use an energy source to keep water in the tank at a predetermined temperature. Whether the appliance is powered by natural gas, oil or electricity, all hot water appliances have features that determine at what temperature the tank's thermostat should be set.

Burn Prevention

The Centers for Disease Control and Prevention (CDC) list many preventive measures homeowners can take to protect children from burns and scalds. One measure is to have the water temperature in a water tank set to 120 degrees Fahrenheit or lower. Some areas even have anti-scalding laws that dictate that water from faucets cannot exceed the CDC-recommended temperature.

Legionnaires' Disease

Legionella pneumophila, a form of Legionnaires' disease, attacks the lungs and can cause severe pneumonia. One common place these bacteria can be found is in warm water storage tanks. Hot water must be stored at a temperature of 140 degrees F to reduce the risk of the growth of the Legionella bacteria.

Thermostatic Mixing Valve

To obtain a faucet temperature that does not exceed 120 degrees F while also maintaining a water tank temperature of at least 140 degrees F, a homeowner can have a thermostatic mixing valve installed. This valve connects the hot and cold water lines to mix the water leaving the hot water tank with the cold water supply. This reduces the water temperature at the faucet to the recommended temperature.

References

• Centers for Disease Control and Prevention: Burn Safety
• SA Health: Legionnaires' Disease