Pratt Plumbing Explains The Temperature Setting For Water Heater

Did homeowners know that they could change the temperature on hot water heater? The maximum temperature on most water heaters is 140 degrees Fahrenheit.

There’s some disagreement among experts on whether it’s best to set it at 140 degrees, or at 120 degrees. Ultimately, it will depend on what’s right for them and their family. In the meantime, let’s take a look at the arguments for both.

120 Degrees

• Because of the energy involved in heating water, setting the heater at 120 degrees makes sense from an environmental standpoint. Reducing the temperature from 140 degrees to 120 makes a significant difference in the amount of energy being used. 
• Reducing the temperature to 120 degrees also saves money, as homeowners won’t be spending as much on the energy to heat the water. 
• Cooler water is also less likely to deposit minerals in pipes, which means users will avoid mineral deposits. This will keep water flowing, and the pipes in better shape. 
• Hot water at 140 degrees can actually cause scalding, which is a big reason to keep it at 120 degrees, especially if users have young children. Kids and elderly adults are more susceptible to scalding, and it can cause major issues. 

140 Degrees

Risk factors for Legionnaires’ disease include old, rusty pipes or water storage areas

Considering the arguments laid out for 120 degrees, why would anyone even bother with setting the temperature at 140 degrees? The answer is that 140 degree water kills a strain of bacteria that can cause Legionnaires’ disease.

This disease can lead to a serious pneumonia-like sickness. Risk factors for Legionnaires’ disease include old, rusty pipes or water storage areas where water sits stagnant for long periods of time. 

What’s Best?

Most homeowners can safely turn their water heaters down to 120 degrees without risk. This is especially true if young children are in the home, as the risk from scalding is much greater than the risk of Legionnaires’ disease. If, however, homeowners have been warned about the possibility of LD bacteria in their area, they will want to turn the temperature up to 140 degrees. 

If homeowners are in an area where LD is a concern, and have young children, they may want to consider installing an anti-scalding device. A tankless water heater, which heats the water as it’s being used, may also be an option. 

Changing the Temperature

Once homeowners have made a decision on what’s best for them, they may need to change the thermostat on water heater. First, determine what temperature water runs at now.

Fill a glass with hot water, and check the temperature, using a kitchen thermometer. If homeowners think they need to change the temperature, consult hot water heater’s manual, to see how to do that. The thermostat may be hidden behind a plate.