Why the ECO reset button on Rheem electric water heater keeps tripping?
The red reset button found on the thermostat of the heating element is also known as the Energy Cut Off or ECO, and a High Limit Control and is designed as the safety device. The switch is designed to cut off the energy to the heating elements (and stop further water heating) of the electric water heater, in a case of the high water temperatures (150 F - 180 F). The tripping protects you from getting scalded or burned when using hot water.
If the ECO reset button trips off you can reset it easily, but it is recommended to investigate the reasons and how often does it happen. When you press the reset button, you can hear a metallic “click” sound. During the normal operation the contacts below the reset button allow the current to pass from terminals to terminals, and that can be checked with the voltmeter. During the abnormal operation, the plate which is under the button, as seen on the Rheem electric water heater, will change its shape pushing the pin out, making the ECO to trip. In such a case, the voltmeter will measure no current running between terminals and to the heating elements.
Water inside the tank has to cool down before being able to reset the ECO (tip: run hot water from a nearby faucet to cool the tank).
Note: It will be assumed that the wiring and electric panel with breakers were done properly and per codes – and if it looks suspicious, have an electrician checking the proper size of the wire and breakers.
One of the reasons why the reset button trips is when the thermostat has failed and got locked in the ON position, making one of the heating elements to heat water all the time. In a case when the water reaches the high limit temperature, the reset button trips. The solution is to replace the faulty thermostat.
Loose wire connections can generate heat, burned wires, melting and smoke, and are affecting the thermostat and tripping the ECO. Solution for this problem is to replace the loose wire or part with the loose wire, check all other related connections and make it tight.
Also, the reset button trips when thermostat does not read water temperature properly, especially if the thermostat is exposed when the insulation and cover are removed.
ECO trips when the heating element is shorted to ground resulting in constant water heating. In order to fix the problem, disconnect the wires and take continuity reading. If it says 0.0 on the terminal, you have a shorted element and it has to be replaced.
In order to prevent or reduce the number of ECO reset tripping occurrences, maintain your electric water heater regularly; making sure there is no leaking, the thermostat is properly installed – flash and firmly mounted against the heater’s wall with all the wires tightly screwed in and insulation in place.