Electric Water Heater Repair

How an electric water heater works

Knowing the layout makes the repairs make sense. Most residential tanks have two elements, an upper and a lower, each with its own thermostat behind a removable panel. The upper thermostat also carries the high-limit switch, which A.O. Smith calls the ECO (Energy Cut Off). Power comes from a dedicated double breaker in your panel.

The upper element heats first. Once the top of the tank is hot, the upper thermostat hands power to the lower element. That's why the symptom tells you a lot about which part failed.

Common problems

1. 1

   Cause 1: Tripped breaker

   A.O. Smith calls a tripped breaker a very common reason an electric heater stops working. Reset it once. If it trips again, don't keep resetting it. A.O. Smith says to check for shorts, loose wires and grounded elements. A grounded element is one that's shorted to the tank. See water heater breaker keeps tripping.

2. 2

   Cause 2: The high-limit (reset) button tripped

   The ECO cuts power when the water gets too hot. To reset it, A.O. Smith's steps are: turn off the breaker, remove the access panel over the upper thermostat, and press the red reset button until it clicks. If it trips again, A.O. Smith points to shorted elements or faulty thermostats and says to call a professional. A bad lower thermostat or a grounded element is often the cause. More on the water heater reset button.

3. 3

   Cause 3: A failed heating element

   A dead element is a common part failure on an electric heater. The symptoms depend on which one:

   • Lukewarm water that runs out fast: usually the lower element.
   • No hot water at all: often the upper element or upper thermostat, since the upper thermostat controls power to both.

   A.O. Smith says faulty elements should be replaced. Elements caked in scale also make crackling or popping sounds, and can be cleaned or replaced. Test with a multimeter before buying parts. Our guides cover how to test a water heater element and how to replace a water heater element.

   One practical note: elements come in different wattages and voltages. Match the stamp on the old one. A different element can overload the circuit or underheat the tank.

4. 4

   Cause 4: A bad thermostat

   A faulty thermostat causes temperature swings and can trip the high-limit switch. If both elements test good but the water is wrong, the thermostat is next. Thermostats are tested with the power on, which is why many homeowners hand this step to a pro. See water heater thermostat.

5. 5

   Cause 5: Loose or burned wiring

   Heat cycles loosen terminal screws over time. A loose connection runs hot, scorches the wire and the terminal block, and eventually fails. If you see browned insulation or melted plastic behind a panel, replace the damaged parts and fix the connection. If the scorching runs back into the wire feeding the heater, that's an electrician's job.

Problems that aren't a failed part

Before you start testing, rule out the simple stuff.

Recovery time. After heavy use, an electric tank needs time to reheat. A.O. Smith puts it at about 60 to 90 minutes for electric, against 30 to 40 for gas. A tank that's slow but eventually hot may be working fine.

The thermostat setting. A.O. Smith recommends 120°F as the balance of heating speed, cost and safety. Someone may have turned it down.

Sediment. Hard water leaves scale in the bottom of the tank and on the lower element. A.O. Smith suggests draining a few gallons from the tank yearly, more often with hard water. Our no hot water from an electric water heater page covers more of these quick checks.

What it costs

HomeGuide's 2026 figures for electric water heater repairs:

Plumbers charge $45 to $150 an hour, and many add a $50 to $200 service call fee. The parts themselves are inexpensive, so DIY saves most of the bill if you're comfortable working on a high-voltage appliance with the power off. Compare part by part on water heater repair cost.

Repair or replace

HomeGuide suggests replacing instead of repairing when the heater is more than 10 years old or the repair costs more than half the price of a new heater. Its lifespan range for tank heaters is 8 to 15 years. An element on a young tank is an easy repair. An element on an old tank with rust at the base is throwing good money after bad.

When to call a pro

Call a plumber or electrician when:

• the breaker or the reset button trips again after one reset
• you see scorched wiring or melted plastic
• you're not comfortable testing live thermostats
• the tank is leaking