As the water temperature increases, the faster pathogens are killed. That's one reason why some health experts recommend 140 degrees Fahrenheit for households with family members who may be immunocompromised. It is important to point out, however, that 140 degrees is very hot.
So no, turning the temp setting up on your water heater doesn't make more hot water, you can only have the volume of your tank hot at any one time. But yea, turning the temp setting up on your tank can make more hot shower water as it lasts longer mixed with the cold to bring it down to optimum temperature.
Savings resulting from turning down your water heater temperature are based on reducing standby losses (heat lost from water heater into surrounding area). Set too high, or at 140ºF, your water heater can waste anywhere from $36 to $61 annually in standby heat losses.
As the temperature gets higher, pathogens die off quicker. For that reason, other agencies like the Occupational Safety and Health Administration (OSHA) recommend a water heater temperature of 140 degrees Fahrenheit.
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 it too high and maximum temperatures will be scalding. Too low and you'll never enjoy the comfort of a hot shower. Not to mention, usually the higher your heater temperature is set, the more costly your energy bills will be.
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting.
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.
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.
Elevating a Water Heater Addresses Safety Concerns
By raising the appliance above the floor level, the risk of potential hazards is significantly reduced. In areas prone to flooding, such as basements or utility rooms, a water heater sitting directly on the floor can be vulnerable to damage from rising water levels.
OSHA, on the other hand, recommends setting your water heater to 140 degrees in order to aid with cleaning and sanitation. Anything between 120 and 140 degrees is within the safe range, which means it really all comes down to a matter of personal preference.
For instance, a typical shower uses about 10 gallons of hot water. So, if you have a 40-gallon hot water tank, you should be able to get four average-length showers out of your hot water tank. This also depends on how much hot water you use for other things.
Turning your water heater off completely when it's not in use can help you save a small amount of money each month on your energy bills, but the hassle of manually turning your unit off and on typically outweighs the benefits.
Raising the temperature setting on your water heater ultimately makes your hot water supply last longer. It will ensure everyone gets a hot shower, with plenty leftover to run your dishwasher and washing machine.
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.
Common sense tells you the water heater doesn't use electricity when it's shut off so clearly you can save money. The energy experts say it's about $1.36 a day. The question you have to answer is whether it's worth it because there are some inherent problems with turning a water heater on and off.
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.
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 recommended temperature setting for a water heater is 120 degrees. This temperature is not only energy efficient, but it can also help extend the life of your water heater and reduce the risk of leaks or other malfunctions, saving you money!
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.
Anything above 120°F is shown as scalding. Please also note that 120°F = 48.8888… °C or approximately 50°C.
If you opt to lower your water heater temperature, additional savings can come from the reduced energy required to heat the same amount of water to 120 degrees instead of 140 degrees. Experts also recommend turning down your water heater to its lowest settings if you plan to be away for an extended period.
General Recommended Water Heater Temperature
If you go to the Environmental Protection Agency, you'll receive a recommended water temperature of 120 degrees Fahrenheit.
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.
In areas likely to flood, water heaters should be elevated at least 1 foot above the base flood elevation (BFE). In seismic areas as well as areas prone to coastal flooding, storm surge, and severe high winds, the water heater should be secured to prevent it from toppling.