Water heaters overheat for many reasons which can range from a broken thermostat to heating elements that have malfunctioned. And water temperatures that reach 140 degrees Fahrenheit or more can cause severe skin burns not to mention getting a high electric bill.
A Broken Thermostat
Both gas and electric water heaters utilize a thermostat, which is a device that controls the temperature settings. If you notice that the water is scalding hot, it is the first thing you’ll want to check. When the thermostat works properly, it will detect the water temperature and make the necessary adjustments, but if it’s broken, the temperature readings may be lower than they actually are. It is also possible that your safety trigger has malfunctioned. In either case, repairing or replacing a thermostat is a complex procedure that will require the assistance of a plumber.
The Pressurized Relief Valve is Obstructed
The pressurized relief valve is an essential component. Water within the tank becomes heated which generates steam, then the pressurized relief valve will aid in releasing it which regulates the pressure of the tank. However, should something block or obstruct the valve, the interior tank pressure will increase, which will cause the water to overheat, and if the problem isn’t resolved promptly it can even lead to an explosion. As you can imagine, this is not a problem you want to tackle yourself and should instead call a plumber and make it clear to them that you have an emergency.
The water within heaters is not pure and will instead contain a variety of minerals that aren’t always filtered out when the liquid is treated, and water that has an elevated mineral concentration is classified as being hard water. If the scale buildup continues, it can lead to overheating because the minerals will settle near the heater’s bottom where they will produce a thick layer of sediment.
The layer will create an environment where additional energy is needed to make the water hot. Once overheating occurs the water temperatures will usually be much higher than whatever temperature you set it to, and it may also reduce the lifespan of the unit.
You Have A Faulty Tempering Valve
The tempering valve is a component that is calibrated to restrict the water’s temperature so it doesn’t go higher than 120 degrees Fahrenheit. In the event that the tempering valve becomes faulty, the water might come out substantially hotter than normal, causing severe skin burns. It should also be noted that tempering valves are a newer technology that will not be present on older water heaters, but because many states mandate them by law, you’ll need to get one installed if you don’t already have it.
Problems With The Heating Element
Most electric water heaters are composed of 1 or 2 heat elements within the tank which aid in heating up the water. Should the water suddenly become scalding hot, it could mean that one of the elements has become stuck. The lower element will sometimes stick to the bottom sediment layer, which means it will heat continuously.