Information current as of 08/23/2026.
For most U.S. homes, set the water heater to 120°F (49°C) as a starting point. This setting can reduce water-heating costs by approximately 6%–10% and lowers—but does not eliminate—the risk of tap-water scalds. Check the actual temperature at the tap, follow the manufacturer’s instructions, and use professional guidance before choosing a higher setting.
Start with 120°F for most U.S. homes
The U.S. Department of Energy recommends 120°F (49°C) for most residential water-heater applications. The EPA says lowering the setting to 120°F can reduce water-heating costs by approximately 6%–10%. This is a practical starting point, not a universal setting for every appliance, household, or building system.
Balance energy savings with scald protection
A 120°F setting generally balances energy use with reduced scald risk. However, 120°F water can still cause severe burns after prolonged exposure, so households with young children, older adults, or people at increased risk of burns should give added attention to anti-scald protection and supervision. The temperature stored in the heater may also differ from the temperature delivered at a faucet or shower; verify the actual tap temperature carefully.
When a higher temperature may be considered
The CDC says setting a home water heater to 130°F–140°F can kill germs such as Legionella, but the hotter water increases burn risk. If a higher storage temperature is selected, thermostatic mixing or tempering valves can mix cold water with hot water before it reaches residential taps. Do not raise the temperature solely to save energy, and do not treat 120°F as eliminating Legionella risk.
Residential systems are different from managed buildings
CDC building-water guidance uses higher storage temperatures and circulation controls for Legionella management than ordinary residential energy-saving advice. In some institutional, healthcare, hotel, or large centralized systems, water-management requirements may call for different targets. Apartment residents and households with centralized systems should consult the landlord, building manager, or a qualified water-management professional before changing the setting.
A simple decision guide
For a typical U.S. home focused on energy use and scald reduction, begin at 120°F (49°C). If a dishwasher, laundry appliance, or other equipment requires a different temperature, check its manual to see whether it provides internal heating or specifies a minimum temperature. If the heater is intentionally operated above 120°F for a documented health or system-management reason, use appropriate mixing or tempering controls and obtain qualified guidance. In every case, follow the water-heater manufacturer’s instructions and applicable local requirements.
Sources
- Purchasing Energy-Efficient Residential Water Heaters
- Pollution Prevention Tips for Energy Efficiency
- Publication 5098 – Tap Water Scalds
- Preventing Waterborne Germs at Home
- Monitoring Building Water
- Legionnaires’ Disease Prevention: Providing a Home for Guests, not Legionella
Frequently asked questions
What temperature should my water heater be set to?
For most U.S. residential applications, set it to 120°F (49°C) as a starting point. Confirm the actual temperature at the tap because the delivered temperature can differ from the heater’s thermostat setting, and remember that 120°F water can still burn after prolonged exposure.
What temperature should a water heater be set at to prevent scalding?
A 120°F setting reduces scald risk compared with hotter settings, but it does not eliminate the possibility of serious burns. Test the actual tap temperature carefully and use appropriate anti-scald or mixing controls when needed.
What temperature should an electric water heater be set at?
For most U.S. residential applications, an electric water heater should start at 120°F (49°C), subject to the manufacturer’s instructions and household or appliance requirements. This setting may reduce water-heating costs by approximately 6%–10%.
What temperature should a gas water heater be set at?
For most U.S. residential applications, a gas water heater should start at 120°F (49°C), subject to the manufacturer’s instructions and household or appliance requirements. Higher settings should not be chosen solely for energy savings because hotter water increases burn risk.