How to Check Heating Element in Water Heater: A Step-by-Step Guide

How do I safely disconnect power before checking a water heater element?

The most crucial step before checking a water heater element is to completely disconnect the power supply at the circuit breaker. Locate the breaker labeled for the water heater in your electrical panel and switch it to the “OFF” position. This ensures there is no electricity running to the water heater, preventing electrical shock and serious injury.

Before touching any electrical components, double-check that the power is indeed off. Use a non-contact voltage tester (NCVT) to confirm the absence of voltage at the water heater’s access panels. Hold the NCVT near the wires and terminals; if it doesn’t light up or beep, the power is likely off. However, even with the NCVT indicating no voltage, it’s still wise to proceed with caution. As an additional safety measure, it is recommended to turn off the main breaker for the entire house during this process. While the water heater breaker should suffice, cutting off all power eliminates any chance of accidental back-feeding or other unforeseen electrical issues. Always prioritize safety when working with electricity.

What multimeter setting should I use to test the heating element?

To test a water heater element with a multimeter, set it to the Ohms (Ω) setting, typically the lowest range available. This allows you to measure the resistance of the element, which is crucial in determining if it’s functioning correctly.

To elaborate, when a heating element is working, it should have a measurable resistance value. A reading of infinity (OL or open loop on many multimeters) indicates a break in the element, meaning it’s no longer conducting electricity and needs replacement. A very low resistance reading, close to zero, could suggest a short circuit, which is also a fault. The expected resistance value will depend on the element’s wattage and voltage, but generally falls within a range of 10 to 20 Ohms. Before testing, always disconnect power to the water heater at the breaker. Then, disconnect at least one of the wires connected to the heating element itself. This ensures that you’re only measuring the resistance of the element and not any other part of the circuit. Remember, safety first! Wear appropriate safety gear, and if you are uncomfortable working with electricity, it’s always best to consult a qualified electrician.

How do I remove the heating element from the water heater tank?

After you’ve confirmed a faulty heating element through testing, removing it involves a few straightforward steps, but safety is paramount. First, shut off the power to the water heater at the breaker. Then, drain the tank completely to avoid a flood. Disconnect the wiring connected to the element, typically two wires. Finally, use a specialized heating element wrench (or a socket wrench of the correct size) to unscrew the element counterclockwise. It may require some force, especially if the element is old and corroded.

Removing the heating element can be tricky, especially if it’s been in place for a long time. Mineral buildup and corrosion can cause the element to seize. Before applying excessive force, try applying a penetrating oil like WD-40 around the element’s threads and let it sit for 15-30 minutes. This can help loosen the corrosion and make removal easier. Use consistent, steady pressure to unscrew the element; avoid jerking or using excessive force, as this could damage the tank threads. Once the element is loose, be prepared for a small amount of water to still drain from the tank as you fully remove it, even after a complete draining. Carefully inspect the threads on both the element and the tank opening for damage. If the tank threads are damaged, you may need to consult a plumber or consider replacing the entire water heater. Before installing a new element, clean the tank opening threads to ensure a proper seal. Applying Teflon tape to the threads of the new heating element is highly recommended to prevent leaks.

What resistance reading indicates a good heating element?

A good heating element in a water heater typically shows a resistance reading within 8 to 16 ohms when tested with a multimeter. This range indicates that the element has continuity and is capable of heating water efficiently. However, the precise reading varies based on the element’s wattage and voltage.

The specific resistance range depends on the wattage of the heating element. Higher wattage elements will have lower resistance, while lower wattage elements will have higher resistance. To determine the expected resistance, you can use Ohm’s Law (Resistance = Voltage² / Wattage). For example, a 240V, 4500W element should read approximately 12.8 ohms (240² / 4500 = 12.8). Always consult the element’s markings to confirm its voltage and wattage before testing. When testing, a reading of infinity (open circuit) signifies a burned-out element, while a reading of zero (short circuit) or very low resistance indicates a short, often caused by the element touching the tank wall. Any significant deviation from the calculated or expected resistance range suggests a faulty element that should be replaced to ensure efficient and safe water heater operation.

What does it mean if the heating element is visibly damaged?

Visible damage to a water heater’s heating element almost always indicates a problem requiring replacement. The damage might appear as bulging, blistering, cracking, or complete breakage of the element’s sheath. These are signs the element is failing or has already failed, rendering it unable to efficiently (or at all) heat the water in the tank.

Damage typically occurs due to a few common factors. Sediment buildup around the element causes overheating, as the sediment acts as an insulator, preventing proper heat transfer to the water. This leads to the element’s metal sheath weakening and eventually failing. Another culprit is dry firing, which happens when the element is energized outside of water. Without water to absorb the heat, the element quickly overheats and burns out. Ignoring a damaged heating element can lead to further complications. A severely damaged element might short circuit, tripping the breaker and cutting off power to the water heater. In some cases, a compromised element can even corrode the tank itself, leading to leaks and the eventual need for a full water heater replacement. Therefore, if you observe any visible damage to a heating element, it’s crucial to replace it promptly. Replacing the heating element is generally more affordable than replacing the entire water heater.

Can I replace just one of the two heating elements in your water heater?

Yes, you can replace just one heating element in your water heater if only one is faulty. There’s no requirement to replace both simultaneously if the other is functioning correctly. However, it’s a good idea to inspect both elements and the overall condition of your water heater before making your decision.

Replacing only the faulty element can save you money and time. However, consider the age and condition of the other element. If the other element is old, corroded, or showing signs of wear, it might fail soon after you replace the first one. In that case, replacing both simultaneously can prevent a second repair job shortly down the line, saving you from draining the tank and repeating the process.

Before replacing any element, it’s crucial to properly diagnose the problem. A multimeter is used to check the continuity of each element. If an element shows no continuity (an open circuit), it’s faulty and needs replacement. Visually inspect the elements for any signs of damage, such as bulging, cracks, or excessive corrosion. Also, checking the thermostat associated with the faulty element is important, as a malfunctioning thermostat can prevent the element from heating even if it’s in good working condition.

Here’s how to check heating element in water heater

1. Turn off the power: Completely disconnect the power to the water heater at the circuit breaker. This is crucial for your safety.

2. Drain the tank: Drain the tank below the level of the heating elements. There’s usually a drain valve near the bottom of the tank.

3. Remove the access panels: Locate and remove the access panels covering the heating elements.

4. Disconnect the wires: Carefully disconnect the wires from the heating element terminals.

5. Test for continuity: Use a multimeter set to the ohms (Ω) setting. Place one probe on each terminal of the heating element.

   • Good element: The multimeter should show a reading, indicating continuity. This typically ranges from 10-20 ohms.
   • Bad element: The multimeter will show no reading or an infinite resistance (OL or similar), indicating an open circuit and a faulty element.

6. Inspect the element: Visually inspect the element for damage.

If the tests determine one is faulty replace it and check functionality, if both are faulty replace both.

What other water heater parts should I inspect while checking the elements?

While you’re disconnecting the power and draining the tank to check the heating elements, it’s wise to inspect other crucial components for signs of wear, corrosion, or failure. This proactive approach can help you identify potential problems early, preventing future breakdowns and extending the life of your water heater.

Beyond the heating elements, pay close attention to the anode rod. This sacrificial rod is designed to corrode instead of the tank itself, preventing rust and leaks. If the anode rod is significantly corroded or depleted, it needs replacement. Also, examine the thermostat(s) for any signs of damage, burnt wiring, or loose connections. A faulty thermostat can cause inconsistent water temperatures or prevent the heating element from working altogether. Check the wiring for any signs of burning, melting, or corrosion as well. Finally, inspect the tank itself for any signs of leaks, rust, or bulging. Look closely around the inlet and outlet pipes, the drain valve, and the pressure relief valve. If you see any signs of water damage or corrosion, it could indicate a more serious problem with the tank’s integrity. Examine the pressure relief valve by manually testing it (carefully!), ensuring it releases pressure smoothly and doesn’t leak afterwards. A malfunctioning pressure relief valve can lead to dangerous pressure buildup in the tank. Replacing a faulty valve is a simple and inexpensive safety measure.

And that’s it! Hopefully, you’ve been able to successfully diagnose your water heater’s heating element. Remember to always prioritize safety when working with electricity and plumbing. Thanks for following along, and we hope this guide has been helpful. Feel free to come back anytime you need a little DIY guidance!