What's the Best Temperature for Your Water Heater?

If you've scalded your hands washing dishes or turned your shower to the hottest setting only to wash off in lukewarm water, your water heater may be set to the wrong temperature. While many homeowners don't think about changing the settings on this household staple, you'll be glad to know how to change it if you encounter any issues. So, how do you know what the right temperature is? We will dive into that and more in this water heater temperature setting guide.

What's the Best Temperature for Water Heaters?

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. So, while setting the temp to 120°F may save on energy costs and avoid scalding, it's ideal to keep things a bit warmer for safety. And if you like to keep your water hotter, use extra caution to prevent scalding.

But before you can change the temperature settings on your water heater, there are a few things you'll need to know.

How Do I Find the Temp on My Hot Water Heater?

You may not be able to read the exact temperature of your water heater based on the dial, as many are just marked from “low” to “hot” or “very hot.” You may be able to find the corresponding temperatures in your owner's manual or online with the make and model information. But if you want to check or test the actual water temperature, you'll need to check the water coming from your tap.

How to Adjust Water Heater Temperature

Before you start this process, do not use your hot water for at least two hours. This will allow it to heat up in the tank. (If you have a tankless heater, skip this step.) Then, let the hot water run for at least three minutes before testing its temperature with a thermometer. Ideally, use a meat, water, or candy thermometer. Once you've established the water temperature, you can turn your water heater up or down accordingly.

After adjusting the hot water temperature, wait a whole day to allow the water temperature to change, then test it again.

Pro tip: When you find the right temperature on your hot water heater, mark it on the dial with a permanent marker!

How Do I Find the Right Temperature for My Water Heater?

If you're not satisfied with the current temperature of your hot water, you may be wondering how to determine the new setting. There are a few factors to remember when making this adjustment; let's review them to help with your decision.

Hotter Water = Less Bacteria

Setting your water heater to a higher temperature can help prevent germs like the bacteria Legionella (the cause of Legionnaires' disease). Scale and sediment can build up in pipes, creating the ideal conditions for harmful organisms that thrive below 120 degrees Fahrenheit. Setting the water heater at or above the USDA's recommended water heater temperature of 122 degrees Fahrenheit can help prevent bacteria growth in your hot water.

High Temps = Burn Risk

While it may be suitable for killing germs, hot water is also a leading cause of burn injuries in the home – especially for young children and older adults. The U.S. Consumer Product Safety Commission (CPSC) warns that 150-degree water can cause burns in as little as two seconds. The lower the temperature, the longer you would need to be exposed to experience a burn.

Consider Energy Costs

The higher you set the temperature on your water heater, the more energy you'll consume to keep it there.

Pro tip: Tankless water heaters are typically less affected by temperature changes than tank heaters.

You've Found the Right Temp – Now Protect It

Once you've worked to find your ideal water heater temperature, don't let unexpected breakdowns leave you out cold. A home warranty from First American can provide peace of mind by protecting your water heater and other home when they break. Learn more about our water heater coverage or get a free quote today to protect your home.

The contents of this article are provided for general guidance only. First American Home Warranty does not assume any responsibility for losses or damages as a result of using this information.

Please be aware that if you disassemble a covered system or item, it can invalidate your home warranty or manufacturer's warranty.