Help! My Electric Water Heater Thermostat Keeps Tripping

2018 Jan 18
Posted in: Electrical
tankless water heater problems in Phoenix

First off, your electric water heater can actually “trip” 2 different safety features:

  1. The reset button: a red button located on the water heater itself (just above the thermostat) that trips when the water temperature exceeds 180° F. The reset button is sometimes referred to as the “ECO” (emergency cut off) or “high limit switch”.
  2. The circuit breaker: a safety device located in your home’s main electrical panel that trips when your water heater tries to pull more current than it’s designed to handle.

A number of problems can cause a water heater’s safety features to trip, including:

  • A bad thermostat
  • A bad reset button
  • Faulty wiring
  • A bad breaker
  • A bad element

Unfortunately, all of these problems require a professional. But in the meantime, don’t continue to reset either of these safety features if they’re continuously tripping! They’re doing their job: preventing a dangerous situation.

Want to learn more about the issues that are stealing your hot water? Then read on.

4 possible problems that are causing your water heater to trip

1. A bad thermostat

Electric water heaters have 2 thermostats—an “upper” thermostat and a “lower” thermostat. The upper thermostat controls the upper heating element and the lower thermostat controls the lower heating element. 

These elements are designed to cycle on and off one after the other to keep the water in the tank hot and ready for use.


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One common thermostat problem with electric water heaters occurs when the lower thermostat becomes “stuck” in the ON position and doesn’t cycle the lower element off properly. When this happens, heat builds up in the upper portion of the storage tank, which will eventually trip the reset button.

The good news? It’s relatively straightforward and affordable to have a professional replace a bad thermostat.

2. A bad reset button

Like we mentioned above, your water heater’s reset button is designed to trip and cut power to the unit if the water temperature surpasses 180° F.

Over time, though, this switch weakens and will have trouble reading the water temperature accurately. If this happens, the switch will trip and cut power to the water heater regardless of the water temperature.

3. Faulty wiring

If you have aluminum wiring that runs from your water heater back to the electrical panel, it could be triggering electrical problems that eventually lead to the circuit breaker tripping.

Here’s why: that aluminum wire has to connect to your water heater’s wiring—which happens to be copper (not aluminum). And, unless a special lug connector is used, connecting aluminum to copper wiring can cause electrical problems.  

You see, because the two metals are dissimilar, the wires will expand and contract and eventually cause the wire nuts holding the wires together to loosen. This causes electrical arcing (when electrical current jumps a gap between two wires) which will eventually trip the water heater’s breaker.

4. A bad breaker

Sometimes, the problem isn’t with the water heater itself but with the circuit breaker that’s protecting it. You see, circuit breakers don’t last forever—they eventually wear out and fail. And if your water heater’s circuit breaker has failed, it’s likely tripping for no real reason.

A circuit breaker can fail due to:

  • Age
  • Continuous tripping
  • Corrosion due to humidity/chemicals in the air

You’ll know that your water heater’s circuit breaker has failed if the breaker doesn’t firmly click into either the “ON” or “OFF” position. If that’s the case, you’ll need to have an electrician replace your water heater circuit breaker.

5. A bad heating element

As we mentioned above, electric water heaters use two “elements” that heat the water. These elements are basically metal loops inside the tank that house electric wires. As current runs through these wires, the elements heat up and warm the water.

But sometimes, the metal casing of an element can crack and expose live electrical wires to the water inside the tank (or the tank itself), creating a short circuit. This short circuit will automatically cause the water heater’s circuit breaker to flip.

If this happens, you’ll need to have a professional replace the bad heating element in your water heater.

Need help from a Phoenix plumber?

If you’re in need of professional water heater repair, just contact us.

We’ll send over a professional who can quickly and safely inspect and repair your water heater.

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