Many water heaters are preset to 140 degrees. This is a great heat range because the bacteria, legionella, are not able to multiply and almost all are unable to survive in such scorching temps. Even so, 140 degrees can be too hot for small kids and seniors. If one is making an effort to conserve cash as well, consider modifying the water temp to around 120 and 130 degrees. The financial savings is not extremely substantial, but this is the minimum recommended temp to avoid contaminating water with legionella. While this bacteria is fine to consume, it can be extremely harmful if taken into the lungs. Legionella lives and multiplies in warm water but not in hot water. But, when considering what temperature to set ones water heater to, it is important not to set it too high. Second and third degree burns can take place on adult skin in five seconds under the preset temp of 140 degrees, so never set the water temperature any higher and consider setting it lower if there are young kids or elderly people in the household. Take a look at this post to learn more about the legionella bacteria and how to decide on the perfect water heater temperature setting. Learn more about water heater repairs here.