How to Replace an Electric Water Heater Element and Testing Tips

Are you tired of cold showers and inefficient heating?

Imagine regaining control over your water heater’s performance with a simple DIY fix. In this comprehensive guide, you’ll learn how to replace an electric water heater element and discover how to properly test it. We’ll address common problems like grounded and open elements, ensuring you’re equipped to handle any issues that arise.

But before diving into the hands-on steps, let’s first become familiar with heating elements: how they work, what types are available, and why proper maintenance is crucial for your home’s comfort.

Testing the Heating Elements

If you’re wondering how to replace an electric water heater element, the first step is testing the current parts to determine if they’re faulty. Testing is a simple process. You can verify their condition by using a multimeter or a non-contact voltage tester. Follow these steps to ensure accuracy:

1. Power Off:
   Before you begin, ensure the power to the water heater is turned off at the electrical panel. This is a critical safety precaution.
2. Safety Check:
   Use a multimeter or a non-contact voltage detector to double-check for any residual voltage on the terminals. Confirming that there’s no live current protects you from electrical hazards.
3. Access the Element:
   Remove the access panel, insulation, and plastic safety cover to expose the heating element. Take your time during this step to avoid damaging any components.
4. Disconnect Wires:
   Carefully disconnect the wires from the heating element. Make a note of their arrangement for a correct reconnection later.
5. Set Your Multimeter:
   Adjust your multimeter to the OHM (resistance) setting. This will allow you to measure the resistance of the heating element accurately.
6. Testing for Grounding:
   Place one test probe on a terminal (screw) of the heating element and the other on any metal part of the tank. If the multimeter’s needle moves, the element is grounded. A grounded element typically shows signs such as boiling water and frequent tripping of the circuit breaker, and it indicates that the element needs replacing. Be sure to test both screws of the element.
7. Testing for Continuity:
   Now, position one probe on one terminal and the other on the opposite terminal. A functional element will show continuity, meaning current can flow through it. Typically, a 4,500-watt heating element should register around 12-13 ohms of resistance. If the multimeter shows no reading, it signifies an open element, which means the circuit is broken, and the element is faulty.

When to Replace a Heating Element

If your testing indicates that one of your heating elements is either grounded or open, then replacing a heating element becomes necessary. This repair is not only simple but also inexpensive compared to replacing the entire unit. Before purchasing a new element, ensure you identify the correct specifications based on your water heater’s model and wattage.

By following these detailed testing procedures, you can quickly diagnose the problem and decide if replacing a heating element is the right solution for your water heater issues. This proactive approach not only saves you money but also prevents further complications that might arise from a faulty heating element.

How to Replace an Electric Water Heater Element: DIY Tips

Once you’ve confirmed that the heating element is defective, it’s time to replace it. Replacing the lower and upper heating elements is not a difficult task and can be done without requiring advanced knowledge or professional tools. However, keep in mind that, for some DIY enthusiasts, the process might be time-consuming. Here’s what you need to do:

Tools Required

• Multimeter – To test for voltage and resistance
• Non-contact voltage tester – For added safety
• Ratchet wrench and sockets – To remove and secure the element
• Pliers and Screwdrivers – For disconnecting wires and removing covers
• Garden hose – To help drain the tank
• Rugs or absorbent materials – To catch any water spills

Tip: Plumbers use a variety of tools to perform their job, from basic hand tools to more specialized equipment. This guide covers some common, readily available tools for plumbing tasks.

Step-by-Step Instructions

Before replacing a broken heating element, ensure that the new part matches the old one in flange, gasket, wattage, and voltage specifications. This ensures a proper fit and optimal performance.

• Turn Off the Power:
  Switch off the water heater’s power at the circuit breaker to eliminate any risk of electrical shock.
• Shut Off the Water Supply:
  Close the cold water supply to the unit. Then, open the TPR (Temperature and Pressure Relief) valve and a nearby hot water tap to release pressure. Follow this by draining the tank until the water level is below the element you plan to replace.
• Remove the Cover and Expose the Part:
  Remove the access panel, insulation, and plastic safety cover to reach the heating element and thermostat.
• Confirm No Electricity:
  Double-check that there is no voltage present on the part’s screws using your multimeter or non-contact voltage tester.
• Disconnect the Element:
  Loosen the screws and carefully disconnect the wires from the heating element.
• Remove the Old Heating Element:
  Using a large socket with a hole or the appropriate wrench (depending on the type of element), remove the defective heating element.
• Install the New Part:
  Place a fresh rubber gasket on the new element. Install the part, ensuring it is properly secured.
• Reconnect the Wires:
  Attach the wires back to the new element, making sure they are tight and properly connected.
• Refill the Water Tank:
  Open the main water valve to allow the tank to fill. Open a hot water tap until all trapped air is expelled from the system.
• Inspect for Leaks:
  Carefully check for any leaks around the new installation. Address any issues immediately to prevent water damage.
• Replace Insulation and Cover:
  Once you’re confident that there are no leaks, put the insulation and access cover back in place.
• Restore Power:
  Finally, turn the power back on at the circuit breaker and run the unit to ensure everything operates correctly.

What Are Electric Water Heater Elements?

Electric water heater elements are immersion heaters that activate when electricity flows through them, heating the water inside a tank-type unit. These parts include a built-in safety device called a high-limit switch, which prevents overheating by regulating the electrical current.

Each heating element works with a thermostat that controls the water temperature. Most electric water heaters—including models from Rheem, AO Smith, and Bradford White—feature two heating elements and two thermostats. These thermostats are surface-mounted for direct contact with the external portion of the heater and can be adjusted manually.

One key advantage of an electric water heater element is its flexibility in installation. Unlike gas devices, which require gas lines and proper venting, electric units can be placed almost anywhere.

Note: The thermostat, heating elements, and internal wiring come factory-installed. For any electrical work, always contact a licensed electrician. Regularly checking your water heater elements helps ensure efficient operation and extends the unit’s lifespan.

Types of Electric Water Heater Elements

Non-Simultaneous vs. Simultaneous

Most residential electric heaters operate on 240V with a 4,500-watt power rating. These are typically non-simultaneous, meaning only one heating element runs at a time.

In a simultaneous configuration, both heating elements operate at the same time, providing a faster recovery rate. However, these models require a higher amperage to function safely.

Good, Better, and Best Heating Elements

Electric water heater elements vary in size and quality. The most common size is 12 inches (300 mm), and the most common shape is U-shaped, screwed into a female-threaded connection inside the tank.

While some parts are shorter and wider, others are longer and narrower. Despite these differences, both designs provide the same heating surface.

Heating elements are typically classified as good, better, and best (premium).

• Good: Standard types
• Better: More durable materials
• Best (Premium): Made from nickel and stainless steel, these ultra-low watt-density elements reduce lime buildup, resist dry-firing, and last longer. Many of these are fold-back elements, making installation easier.

The electrical and wattage rating is stamped on the front of the part. Always match the configuration and model when replacing an old heating element.

A high-limit switch acts as a safety feature, cutting power if the temperature reaches unsafe levels. While you can manually adjust the thermostat using a screwdriver, most safety standards recommend keeping it at 120°F or lower.

How Does It Work

Both the upper and lower heating elements are submerged in water, while the thermostat and high-limit switch are mounted on the tank’s surface.

• Lower Element Activation: When the lower thermostat detects cooler water, it activates the lower heating element.
• Water Heats Up: The element heats the water until it reaches the desired temperature, at which point the thermostat shuts it off.
• Upper Element Activation: If more hot water is used than the lower element can heat, the upper thermostat senses the drop in temperature and activates the upper heating element.
• Heating Cycle Repeats: This process continues as needed.

If your electric unit isn’t heating fast enough, consider replacing the heating elements with higher-wattage models for better performance.

Common Problems and Troubleshooting Tips

Even the best water heaters can run into problems over time. Issues like dry-fired elements, limescale buildup, and voltage spikes can reduce efficiency or cause the unit to stop working altogether. Knowing how to identify these problems early can save time and money on repairs. In some cases, learning how to replace an electric water heater element is all it takes to restore hot water and improve performance.

Dry-Fired Elements

If a tank water heater isn’t completely filled before operation, the heating elements can be exposed to air, causing dry-firing within seconds. This overheats the exposed part, damaging the copper sheathing beyond repair. A dry-fired element often appears deformed, easily bent, and may have melted plastic sleeves.

To prevent this, always ensure the tank is fully filled before turning on the heater. Alternatively, consider installing a dry-fire-resistant heating element for added protection.

Limescale Build-Up

Limescale build-up on heating elements is the result of hot water and mineral deposits working together, especially in regions with hard water. Once formed on the part, limescale acts as an insulator and reduces its effectiveness.

Furthermore, less heat is transferred to the water, and the elements are exposed to higher temperatures, leading to their failure. Regular maintenance, including cleaning and draining, is key to ensuring a long life and high performance.

Voltage Spikes

Lightning strikes and power surges can damage heating elements, often leaving black soot on the part’s head, melted plastic, or swollen and split sheaths. Installing a surge protector can help safeguard your water heater from these sudden spikes.

Wet Heating Element

If a water heater has a leak, water can seep into the element sheath, causing corrosion and failure. This may result in a split or swollen sheath, reducing its effectiveness. Regularly inspecting your heater for leaks and proper sealing can prevent this issue.

Open Circuit

The heating element may not show any signs of deformation, but the inner filament could be broken. The only way to check for this is to test the part for continuity. If there is no continuity, it must be replaced.

Other Causes of Failure

Mechanical stress from vibrations, fluctuating voltage, and improper power supply can also cause components to fail.

• High voltage can burn out an element.
• Low voltage can reduce heat output, making the heater less effective.

Conclusion

A well-maintained water heater ensures consistent hot water and long-lasting performance. By understanding common problems like limescale buildup, dry-fired elements, and electrical issues, you can troubleshoot and resolve issues before they lead to bigger failures.

If testing reveals a faulty part, learning how to replace an electric water heater element allows you to restore efficiency without replacing the entire unit. With proper tools and safety precautions, replacing is a straightforward task that keeps your water heater running smoothly.

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