What It Is
A water heater heating element is a resistive electrical component that screws directly into the tank wall of an electric water heater and generates heat by passing electrical current through a metal coil. Most electric tank-style water heaters have two elements - an upper element near the top of the tank and a lower element near the bottom - each paired with its own thermostat. When an element fails, the heater may produce only lukewarm water or no hot water at all, depending on which element has burned out.
What It Does
Heating elements are the sole heat source in an electric water heater. Unlike gas heaters, which use a burner flame below the tank, electric heaters rely entirely on these immersed resistive coils to transfer heat directly into the surrounding water. Each element is rated in watts — commonly 3,500 to 5,500 watts on residential units, though ratings vary by model and tank size — and cycles on and off as directed by its paired thermostat.
The upper and lower elements work in sequence, not simultaneously. When you call for hot water and the tank cools, the upper element activates first to heat the top portion of the tank quickly. Once the upper thermostat is satisfied, the lower element takes over to heat the rest of the tank. This staged approach allows for faster initial recovery while managing energy use.
Elements are typically made from copper or stainless steel sheathed around a resistance wire, or from a fold-back design that sits fully inside the tank. Sediment from hard water can coat the lower element over time, reducing its efficiency and accelerating failure.
Where It Is Located
Both heating elements screw through flanged ports on the side of the water heater tank body. The upper element is positioned in the upper third of the tank and the lower element near the bottom. Access panels on the front of the heater jacket cover each element and its thermostat. You can see the panels from outside the unit - they are rectangular access plates held by screws.
How It Works
Electrical resistance converts electrical energy to heat. When current passes through the resistive coil inside the element, it heats the metal sheath, which transfers heat to the water surrounding it. The thermostat monitors water temperature at its location in the tank and sends power to the element when the temperature falls below the set point, then cuts power when the set temperature is reached.
Elements fail in several ways: the resistive wire can break (an open circuit, causing complete failure), the sheath can corrode and allow water to contact the wire (causing the circuit breaker to trip), or heavy scale buildup can overheat the element until it burns out.
Common Problems or Signs of Failure
- No hot water at all - both elements have failed, or the upper element has failed and the breaker has tripped
- Hot water runs out very quickly - the lower element has failed, leaving only the upper element to heat a small portion of the tank
- Water is lukewarm but never fully hot - upper element working, lower element failed
- Circuit breaker for the water heater trips repeatedly - a shorted element is likely causing the overcurrent
- Popping or hissing sounds during heating - scale buildup on the lower element overheating under sediment
Can a Homeowner Check It?
You can check the circuit breaker panel to see if the water heater breaker has tripped - that is a safe first step. You can also note whether the water is completely cold or merely not as hot as usual, which helps identify which element may have failed. Testing elements with a multimeter is possible but requires shutting off power, draining water from the tank, and comfort working with electrical components.
- Check the electrical panel - confirm the water heater breaker is not tripped
- Reset the high-limit safety switch behind the upper access panel - press the red button once if it has tripped
- Notice whether water gets warm but not hot vs. completely cold - this helps identify which element failed
- Listen for abnormal sounds during heating cycles - sizzling or popping often indicates sediment on the lower element
When to Call a Plumber
Call a plumber when your electric water heater is no longer producing adequate hot water and the circuit breaker check did not resolve it. Element replacement requires draining the tank and working safely with 240-volt wiring. A plumber can test both elements, replace the failed one, and flush accumulated sediment from the tank at the same time, which extends the life of the new element.
Related Plumbing Problems
- Why Do I Have No Hot Water?
- Why Does My Water Heater Run Out of Hot Water Fast?
- Why Is My Water Heater Making Noise?
Related Plumbing Terms
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