Although some manufacturers set water heater thermostats at 140ºF, most households usually only require them to be set at 120ºF, which also slows mineral buildup and corrosion in your water heater and pipes. Water heated at 140ºF also poses a safety hazard—scalding.
The best temperature setting for a hot water heater is between 120 and 140 degrees. Below 120 degrees, bacteria can develop in the stagnant water sitting in the tank. Above 140 degrees, the water is so hot that you and your family members can be at risk for scalding in as little as two seconds.
If the temperature is set above a safe threshold, such as 140 degrees Fahrenheit, the risk of scalding increases significantly. This can cause painful burns and other serious injuries, especially for children or older adults with more sensitive skin.
Children and older people, who typically have thinner skin, suffer more severe burns in a shorter time and at lower temperatures than adults. A child can suffer a third-degree burn in 124°F water in less than three minutes. Children and adults can be burned this badly in two seconds or sooner in 149°F water.
If you are taking a shower or a bath you can receive severe burns because of scalding hot water. At 140°, water takes only a few seconds to cause third-degree burns, which penetrate the skin and can create permanent scarring.
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting. Most experts agree that anything below 120 degrees creates a risk for bacteria to develop inside your water heater from stagnant water, such as legionella that causes Legionnaire's disease.
At 140 degrees Celsius, water is in a superheated state, which means that it exists in a gaseous phase rather than a liquid phase. The pressure of water in this state depends on its specific volume, temperature, and other properties such as its internal energy and entropy.
What Temperature Should a Water Heater Be Set At? Most water heaters are designed to operate safely at temperatures between 120 and 160 degrees. Many tank-style units also have a low-temperature setting where the unit will only heat up the water to around 90 to 100 degrees.
You can set your residential tankless water heater higher, but know that a child can be burned by 140°F water in just a couple of seconds. For commercial applications with higher demand, 140°F is a good setting.
To help prevent bacteria growth, the ASSE recommends keeping the water in your water heater tank at about 135 - 140 degrees Fahrenheit.
Most adults will suffer third-degree burns if exposed to 150 degree water for two seconds. Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns.
Yes, it's very bad to turn your water heater all the way up. To do so will reduce its life, increase your electricity bill and could possibly cause scalding—particularly if you have young children or an elderly relative living in your home.
120 Degrees is the recommended max temperature for water heaters, according to both the American Society of Sanitary Engineering and the US Department of Energy. Firstly, setting the max temperature to 120 degrees prevents the water from scalding your skin.
How do you know if your water heater is too hot? The easiest way to test your water temperature is to run hot water from your faucet for 3 minutes and fill a glass of water. Insert a thermometer into the water and check the reading, if its is over 120 degrees the water is too hot and can potentially cause burns.
Overheating water heaters sometimes cause corrosion in the tank. This corrosion can cause leaks and other issues.
It takes only 32 minutes on average for Legionella to die at temperatures of 140 degrees, and at 151 degrees, the bacteria will die instantly. This is why disinfection that uses temperature change will set a water heater to approximately 158 degrees for five minutes.
Water heated at 140ºF also poses a safety hazard—scalding. Savings resulting from turning down your water heater temperature are based on reducing standby losses (heat lost from water heater into surrounding area).
So, what is the best temperature range for your water heater? The EPA recommends 120 degrees because it's hot enough to keep diseases at bay but not hot enough to cause scalding. This setting will also supply enough hot water for most small families and is relatively energy efficient.
Actually, they are the same. The recommended temperature setting from the Consumer Product Safety Commission for a tank and tankless water heaters is 120 degrees. The 120-degree setting is especially important for households with elderly occupants or small children to prevent burns.
Understanding these settings can help when figuring out how to adjust the temp on water heater units. A typically represents around 130°F. B usually corresponds to 140°F. C indicates a temperature of about 150°F or higher.
Faulty fixtures or leaking connections and pipes can go unnoticed at the water heater because it is not an appliance you see every day. The leaks can become significant and result in an increase in the water usage bill and your energy usage bill.
Tankless Water Heaters: Tankless water heaters, on the other hand, don't store hot water. They heat water as it passes through the system, often with adjustable thermostats ranging from 100°F to 140°F.
The lower the temperature, the greater the safety and savings in energy cost. To achieve this, we recommend a temperature setting of 120°F or less. Water temperatures over 125°F can cause severe burns instantly or death from scalds.
Live Science writes that most humans can endure about 10 minutes in 140–degree heat before suffering from hyperthermia, a lethal form of which is the aforementioned heat stroke.