Set the temperature too low, and you could turn your water heater into a breeding ground for dangerous bacteria. Set it too high, and you could be setting yourself up for a scalding accident. How Low Can You Go? The short answer: 120 degrees Fahrenheit.
If the temperature is too low, your water heater can become a breeding ground for dangerous bacteria. On the other hand, setting the temperature too high puts your family members at risk of scalding themselves, leading to potentially serious injuries.
That said putting the heater at maximum has two detrimental effects. It can heat the water too high increasing the risk of scalding and two, it can cause build up of pressure that will cause the pressure release valve to open and vent after which you may need a new valve.
Adjusting the Temperature on an Electric Water Heater
For a traditional electric hot water tank, start by turning off power to the water heater. You will find the thermostat in the access panel after opening the cover plate. There may be insulation in front of the thermostat when you open the access panel.
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.
Set too high, or at 140ºF, your water heater can waste anywhere from $36 to $61 annually in standby heat losses. Additional savings will be realized by the lower temperature for consumption (from water demand or use in your home, such as clothes washing, showers, and dishwashing). These may amount to more than $400.
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.
So it's best to make an adjustment and wait 3 hours before testing your water again with a thermometer. Its also a good idea to do one final test in the morning after it has sat over night. If the valve doesn't respond to adjustments or causes too much temperature change then the valve could be bad.
Instead, there's a range: between 120 degrees and 140 degrees. This range exists for a reason: at temperatures lower than 120 degrees, there's a risk of bacterial growth in the water heater. At temperatures higher than 140 degrees, there's a greater risk of accidental scalding.
Well-maintained traditional gas and electric hot water heaters can last 8-12 years, or more, before it's time for a hot water heater repair or replacement. Turning off your unit while you'll be away— or anytime your main water supply is off— is a good way to prolong the life of your system.
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.
Elevating a Water Heater Addresses Safety Concerns
Elevating the water heater helps protect it from water damage and minimizes the risk of electrical malfunctions or gas leaks that could result from flooding.
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.
DON'T set your water heater temperature above 120 degrees Fahrenheit. DON'T keep combustible material within 18 inches of the hot water heater. DON'T leave children unattended around a hot water heater. DON'T allow plaque and sediment to build up in your tank.
The Consumer Product Safety Commission (CPSC) recommends setting the water heater at no more than 120 degrees Fahrenheit (49 degrees Celsius) to prevent scalding. Not to mention, a water heater that is set too high can unnecessarily increase your electricity bill.
Set the temperature too low, and you could turn your water heater into a breeding ground for dangerous bacteria. Set it too high, and you could be setting yourself up for a scalding accident. How Low Can You Go? The short answer: 120 degrees Fahrenheit.
THE DANGERS OF SETTING WATER HEATER TEMPERATURE TOO HIGH
When the temperature is above 140 degrees Fahrenheit, it takes only a few seconds to cause a serious burn. A higher temperature setting can also increase the risk of pressure buildup in the tank, leading to potential explosions or leaks.
If you notice signs of overheating like scalding water, a leaking pressure relief valve, unusual sounds, rusty water, and climbing energy bills, you need to take swift action to repair your water heater before it causes more problems.
If the thermostat on the tank is set to a higher temperature, hot water may run out more quickly. Lowering it just a few degrees won't feel much different (it may even avoid being scalding burns). It'll also avoid a sudden rush of chilly water. Hot water can also run out if the heater is set too cool.
Anything between 120 and 140 degrees is within the safe range, which means it really all comes down to a matter of personal preference. If you have younger children in the house, you are always better to have your water heater set to 120 degrees to prevent scalding.
During the colder months, you may have turned up the temperature to compensate for the colder water. However, during the warmer months, you don't need the water to be as hot, and a lower temperature setting can save you energy and money. Set the temperature to around 120 degrees Fahrenheit.
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.
C - 150° F - About 1-1/2 seconds. B - 140° F - Less than 5 seconds. A - 130° F - About 30 seconds. HOT - 120° F - More than 5 minutes. LOW - 80° F - No hazard.
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.