Your water heater reset button is a safety device that shuts off power to your water heater when the water temperature inside it exceeds 180 degrees Fahrenheit.
Side note: the reset button is also sometimes referred to as the ECO (emergency cut off) switch or “high limit safety thermostat switch”.
So, what’s causing the button to keep tripping? There are a number of possible underlying problems. We’ll show you the 4 most common.
Electric water heaters have 2 thermostats and 2 heating elements. There is an upper and lower thermostat/element pairing as seen in the diagram below.
Diagram of electric water heater. Photo courtesy: Waterheatertimer.org
The thermostat’s job is to monitor the temperature of the water in the tank and shut off the heating element when it reaches your set temperature.
But when a thermostat goes bad, it sometimes gets “stuck” and doesn’t turn off the element it serves. This allows the element to keep heating the water until the reset button trips. If this is the problem, you’ll need to replace the thermostat.
Loose electrical connections are a hazard no matter where they occur. The high resistance caused by a loose wire produces a substantial amount of heat that can eventually cause fires.
If there is a loose electrical connection within your water heater’s system, your reset button’s thermometer can trip (regardless of the water’s temperature) if it picks up the heat from that loose wire.
A short in one of the heating elements allows power to flow through the element even after the thermometer shuts off its power.
This means the heating element is still working and will continue to increase the water temperature, eventually tripping the reset button.
Just like all parts of the water heater, the reset button will eventually suffer from wear and tear. This can cause it to perform less effectively and continually trip regardless of the temperature of the water in the tank.
The reset button is actually part of your upper thermostat. So, if this is the problem, you’ll need to replace the whole thermostat.
Diagnosing this problem on your own is tricky and dangerous because you’re dealing with 240 volts of electricity.
Unless you’re experienced with wiring and electrical components, we suggest leaving it to a professional to pinpoint your specific issue. The good news is that a professional can both test and repair your water heater.