What temperature should most home water heaters be set to?

References

Answer: 120°F. Water at 140°F can cause a bad burn in about six seconds, but at 120°F it takes about five minutes. Some water heaters come set to 140°F from the factory. Turning it down to 120°F also slows mineral buildup in the tank and pipes.

1. Department of Energy: Purchasing Energy-Efficient Residential Water Heaters www.energy.gov/cmei/femp/purchasing-energy-efficient-residential-water-heaters

   For most residential applications, set the temperature at 120°F.

   Checked 2026-10-09.
2. CPSC: Avoiding Tap Water Scalds, 140°F timing www.cpsc.gov/s3fs-public/5098.pdf

   Burns will also occur with a six-second exposure to 140 degree water

   Checked 2026-10-09.
3. CPSC: Avoiding Tap Water Scalds, 120°F timing www.cpsc.gov/s3fs-public/5098.pdf

   Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns.

   Checked 2026-10-09.
4. PNNL Building America Solution Center: Check Water Heater Temperature basc.pnnl.gov/diy-guides/check-water-heater-temperature

   it may help your water heater last longer by slowing down the build up of mineral deposits and corrosion.

   Checked 2026-10-09.
5. EPA: Legionella in the Indoor Environment www.epa.gov/indoor-air-quality-iaq/legionella-indoor-environment

   Legionella grows best at temperatures between 80-120⁰F

   Checked 2026-10-09.
6. EPA: Legionella in the Indoor Environment, scald protection www.epa.gov/indoor-air-quality-iaq/legionella-indoor-environment

   The risk of scalding can be managed with thermostatic mixing valves placed as close as possible to water outlets.

   Checked 2026-10-09.

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