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.
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.
The maximum Department of Energy recommended water heater temperature setting you should never exceed is 140 degrees Fahrenheit. The lowest recommended setting should never be below 120 degrees Fahrenheit.
What's the Optimal Hot Water Heater Temperature? Most hot water heaters are set at the factory setting of 140 degrees Fahrenheit, but this isn't necessarily the best temperature for it. The United States Department of Energy recommends that most people set the temperature at 120 degrees Fahrenheit.
According to Centers for Disease Control and Prevention (CDC), water temperatures ranging from 130 to 140 degrees Fahrenheit(°F) can eliminate most of the harmful bacteria. However, be warned that these high temperatures can also increase the risk of scalding.
To help prevent bacteria growth, the ASSE recommends keeping the water in your water heater tank at about 135 - 140 degrees Fahrenheit.
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.
According to most dermatologists, the ideal shower temperature is anywhere between 98°F (37°C) and 104°F (40°C)—and no more than 105 °F (41°C). Rinsing under lukewarm water allows you to stay comfortable and maintain your body temperature while reaping all the benefits of both hot and cold showers.
The label on the water heater indicates what voltage the water heater requires. Most residential units are 220/240 volts (but some are 110/120 volts).
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.
Most homeowners should flush their water heaters every 6 months or so, but if you have extremely hard water, you may want to do it more often. Flushing your hot water heater could be necessary as often as every few months depending on the mineral content of your local water supply.
As water travels through the pipes in your home, the temperature surrounding the pipes is generally cold in winter. Unless your pipes are insulated, the water coming into and exiting the water heater will be affected by the external cold temperatures, causing the heater to work harder.
If your water heater is set too low, it can create an environment that's ideal for bacteria. Disease-causing microorganisms such as Legionella — which causes Legionnaires' Disease — thrive in lower temperatures.
What is legionella? Legionella bacteria is commonly found in water. The bacteria multiply where temperatures are between 20-45°C and nutrients are available. The bacteria are dormant below 20°C and do not survive above 60°C.
Hot water should be stored at least at 60°C and distributed so that it reaches a temperature of 50°C (55°C in healthcare premises) within 1 minute at the outlets. This page will help you understand how to control risks for different systems, depending on the size and type of building.
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.
The primary way most people notice their water heaters overheating is because the water becomes unbearably hot, scaldingly so. If your water heater is set on too high a temperature, burns, and severe injuries may occur.
"Hot water is typically described as approximately 110 to 140 degrees," says Channa Ovits, M.D., FAAD, a Westchester, New York-based board-certified dermatologist at Westmed Medical Group, a Summit Health Company. But in terms of a shower, you should never tiptoe over 120 degrees, due to the chance of a burn injury.
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.
Explore engineering options (e.g., install pre-set thermostatic valves in point-of-use fixtures for baths, showers, and sinks). The Occupational Safety and Health Administration (OSHA) prescribes storing water at 140°F (60° C) and delivering it at a minimum of 122°F (50° C) to all outlets.
According to experts in plumbing and home safety, a recommended temperature range of 120-130 degrees Fahrenheit is generally considered safe for most households. This ensures that hot water remains comfortable while minimizing the risk of accidental burns.
Manufacturers often recommend a hot water heater temperature between 120 to 140°F, and there's a reason for this. The Occupational Safety and Health Administration (OSHA) recommends a recommended hot water temperature of at least 122 degrees to prevent the growth of harmful bacteria.
Making sure your water heater is always set to at least 120 degrees minimizes this risk, as the water should be hot enough to kill any bacteria. Even though most units will go up to 160 degrees, you really shouldn't ever set the temperature higher than 140 degrees in order to reduce the risk of scalding.