One of the most frustrating things that can happen is to discover in the middle of washing dishes, or taking a shower that the electric water heater in the home is malfunctioning. While many people are familiar with the possibility of the heating element dying, thus resulting in cold water coming out of the tap, the other extreme can also occur, and it’s important to know what can cause an electric water heater to overheat, in order to make the most of any repair efforts.

The temperature setting    

One cause of an overheating electric water heater, and the easiest to take care of, is a temperature setting which is too high. The temperature setting is easily located, generally close to the heating element for the reservoir. If you find that overheating is a problem, check the temperature that it is set to. Generally speaking, 120 degrees Fahrenheit is an ideal level for most household uses, but it can be set higher. It takes only a moment to adjust the temperature setting and see if that helps matters.

The heating elements 

Another cause of electric water heaters overheating is accumulation of dissolved minerals on the heating elements. Most water supplies have some level of dissolved solids (different minerals, often calcium) in them, and over time these can evaporate out of the water and form clumps on the heating element inside the water heater, leading to the heating elements having to work harder. The danger of this is not just overly hot water, but also the failure of the element a short time after the electric water heater begins overheating. This is a more serious issue, and can require professional help.

The thermostat   

After the temperature setting, a thermostat failure is a very common reason for an electric water heater to overheat. The thermostat controls the off and on cycles of heating, and for safety purposes there is a red reset button that triggers in the case that the heating elements fail to cycle off. But if the thermostat fails, the electric water heater just continues to heat the water indefinitely until it’s caught, generally requiring a replacement thermostat module.


While a lack of hot water can be very inconvenient, an electric water heater that overheats can pose significant danger to anyone using the water. By knowing a few of the reasons that the water heater might overheat, it becomes easier to tackle repair efforts and know how much money to set aside to solve the problem.


For more information, contact Vinny’s Jersey Plumbing, located in Wayne, New Jersey.  We also service other towns in New Jersey, such as Livingston, Cedar Grove and Montclair.