Short answer: An electric water heater that trips the breaker or the red reset button (the high-limit or ECO switch) once may just need a reset. If it keeps tripping, A. O. Smith says repeated tripping points to serious problems like shorted (grounded) heating elements or faulty thermostats. These parts are behind panels with live high-voltage wiring, so testing and replacing them is a job for a qualified plumber or electrician unless you are trained.
Quick diagnosis
| What you notice | Most likely cause | What to check | Call a pro? |
|---|---|---|---|
| Breaker trips immediately when reset | Shorted (grounded) heating element or wiring fault | Leave it off | Yes |
| Breaker trips after a while of heating | Failing element, loose connection or undersized breaker | Note timing; check for burnt smell | Yes |
| Red reset button keeps tripping | Overheating: bad thermostat or grounded element | Reset once with power off | Yes, if it trips again |
| Water too hot before it tripped | Thermostat stuck on | Do not use; scald risk | Yes |
| Water on top of heater or near the panels | Leak reaching electrical parts | Turn off power | Yes |
Reset it safely, once
- Turn the water heater breaker off. A. O. Smith warns that water heater parts stay live even when the unit is not heating.
- Remove the upper access panel and insulation, without touching wires.
- Press the red reset button firmly. A click means it had tripped from overheating.
- Replace the insulation and panel, then turn the breaker back on.
Why it keeps tripping
- Shorted heating element: an element that fails to ground trips the breaker or the high-limit switch.
- Faulty thermostat: a thermostat that does not shut off lets the water overheat until the high-limit trips.
- Loose or burnt wiring: loose connections heat up and can trip the breaker; look for discoloration only with power off.
- Water leaking onto the electrical parts.
Do not
- Do not install a larger breaker to stop the tripping.
- Do not hold or tape a reset button in.
- Do not keep resetting it; repeated trips mean a part has failed.
When to call a professional
- The breaker or reset button trips again after one reset.
- You see scorch marks, smell burning or see water near the wiring.
- You are not trained to test elements and thermostats with a meter.
What it usually costs
HomeGuide (2026) lists heating element replacement at about $100 to $350 and thermostat replacement at about $100 to $350, with most standard tank repairs costing $150 to $700.
Frequently asked questions
Is it dangerous if my water heater keeps tripping the breaker?
It means a fault the breaker is protecting you from. Leave it off until it is diagnosed.
Where is the reset button on an electric water heater?
Behind the upper access panel, above the upper thermostat. Turn off the power before opening it.
Related problems
Sources
This guide is general information, not a substitute for an inspection by a licensed professional. See our disclaimer.