Fixing my leaking shower

Why the High Limit Switch on Your Water Heater Trips Repeatedly

by Andy Butler

Electric hot water heaters have a reset button (also called a high-limit switch) that may keep tripping if something is affecting the mechanism that controls the functioning of the heating elements. Such a scenario requires the intervention of an emergency plumber before a major defect, such as a blown tank, occurs leading to your home being flooded. This article discusses some of the factors that may cause that reset button to trip repeatedly.

A Defective Thermostat

Thermostats usually trigger the heating elements to start working or stop working depending on the temperature of the water inside the hot water heater's tank. A defective thermostat can make this mechanism to stop functioning. The result is that the elements will work nonstop until the reset button trips. This continuous operation of the elements can cause them to overheat to the extent that they can burn out or explode. Immediate intervention to correct the problem can restore normalcy to the hot water heater and prevent a catastrophic failure when you keep resetting the high-limit switch without addressing the cause of the problem.

Loose Wiring

A more risky cause of repeated tripping of the reset button is loose wiring within the hot water heater. Such a loose wire may generate so much heat that the reset button will keep tripping each time you reset it. Eventually, the affected wires may burst into flames if they are not allowed to cool during the time when the heating elements cycle off.

A Shorted Element

It is also possible for the thermostats to be functional but the reset button keeps tripping. This can happen when a short circuit within a heating element keeps power flowing to the elements even if the thermostat has sent a signal to cut power to the elements. Such a defect can be catastrophic in case it coincides with another fault within the heater system. For instance, the hot water tank can explode in case a shorted element keeps heating water when a jammed pressure-relief valve cannot allow excess pressure inside the tank to escape.

As you can see, it may be necessary for you to call an emergency plumber in case you notice that the reset button on your hot water heater trips repeatedly. That expert will diagnose the most likely cause of the problem so that an appropriate remedy is quickly implemented before the defect gets out of hand and puts your home at a high risk of flooding or burning down in a fire that starts from the hot water heater.