We have all heard to set your water heater at 120 degrees Fahrenheit. But why? Temperatures above 120 degrees are great for washing dishes.
Safety is the reason and high temperature water is a serious hazard. Following is information about how long it takes for high temperature water to produce severe 2nd and 3rd degree burns on adult skin:
- 160 degrees F. – about 1/2 second
- 150 degrees F. – about 1 1/2 seconds
- 140 degrees F. – less than 5 seconds
- 130 degrees F. – about 30 seconds
- 120 degrees F. – greater than 5 minutes
Children’s skin is much more sensitive and will produce severe burns in less time.
Excessive water temperature is a serious matter and a good home inspector will look for it. Unfortunately, the temperature setting can be changed at any time by anyone so you should check for yourself. Inexpensive thermometers can be purchased to test the delivery temperature at a tap nearest the water heater. We recommend never setting the water heater temperature above 130 degrees F., for any reason.
As Arizona home inspectors, we sometimes we see homeowners set water heaters too high to compensate for an inadequately sized unit. Another reason folks justify an excessive temperature setting is when it takes a long time for the hot water to reach certain fixtures. Others just like the high temperature water. Solar water heaters are notorious for having excessively high delivery water because of missing, damaged or improperly set tempering valves. For this reason we suggest that solar water heaters be evaluated by a solar system expert at transfer of ownership and/or every two years. We also suggest you check your own delivery temperature today, especially if you have children. Maybe this will keep you out of hot water!