Domestic Hot Water Temperature Range

The plumbing codes define hot water as follows.

Domestic hot water temperature range. Elderly homeowners or those with small children may want to keep the temperature at 120 degrees. The 125 degree limit probably allows for some temperature loss before the hot water gets to the fixtures. Hot water should not be stored at temperatures below 60 oc 140 of to avoid the risk of legionella contamination. For canteens and professional kitchen temperatures of 65 oc are often required to satisfy hygienic standards.

If you read the model codes it states the maximum hot water temperature for a shower or bathtub is 120 degrees fahrenheit. Department of energy recommends the 120 degree mark for both maintenance and savings purposes. Homeowners with a dishwasher that does not pre heat the water may want to set their water heater to 140 degrees. No there is no code language addressing a minimum domestic hot water storage temperature.

This does not mean it is good design to store the hot water at 110 f. The mixing valve takes the hot water from the newly set heater 140 f and mixes it with cold water until it can be released from the valve at a safe 120 f temperature. Set the temperature of the water reservoir hot water heater to 140 f but deliver the water at 120 f by way of a mixing valve. However there is less danger of bacterial growth in smaller domestic hot water tanks.

Consequently osha recommends the minimum water heater outlet temperature in residential systems to be set at 130 degrees f to produce a faucet temperature of at least 120 degrees f. Test your water temperature. Guidelines from the department explain that most hot water heaters are automatically set to. Hot water is normally supplied to fittings and their consumers at 50 60 oc.

If you read the warning labels on the side of most water heaters the maximum hot water temperature is 120 degrees fahrenheit on some labels and 125 degrees fahrenheit on other labels. Hot water water at a temperature greater than or equal to 110 f 43 c.