The Ultimate Guide to Testing and Troubleshooting Your Electric Tankless Water Heater's Heating Elements

Are you facing issues with your electric tankless water heater? Don't worry; you're not alone. Whether you have an EcoSmart, Eemax, or Rheem model, one common problem that can impact the performance of your water heater is with the heating elements. Luckily, diagnosing and troubleshooting these issues can be a straightforward process if you follow the right steps. This guide will walk you through everything you need to know about testing your water heater's heating elements to ensure they're in tip-top shape.

Step 1: Locating the Heating Elements

Your water heater's performance hinges on the proper functioning of its heating elements. Here's how to locate and test them:

  1. Identify the Heating Elements: Look for two red wires connected to the top of each heating element. These are your targets for testing.
  2. Power Engagement: To test the elements, you'll need to ensure they're receiving power. Turn on multiple faucets in your home to activate all the heating elements. This step is crucial as the elements need water flow to power up and heat.
  3. Voltage Testing: Using a multimeter, test the voltage across the screws on the top of each heating element, starting with the element furthest to the right (heating element number one). Place one probe on one screw and the second probe on the other screw. You should read between 208-240 volts, indicating proper operation.

Important: Remember, water must be flowing through the heater for the elements to engage and power up.

What If There's No Voltage?

If your LED display is on, indicating the unit is receiving power, but there's no voltage across the heating elements, follow these steps:

  1. Conductivity Test: First, ensure your water heater is off and that you've turned off all associated breakers. Set your multimeter to OHMs and test each heating element for conductivity across the two screws. A healthy element will show an OHMs reading between 6 to 10.
  2. Troubleshooting Thermistors: If the OHMs reading is within the normal range, your heating elements are likely fine, but you may have an issue with your thermistors. Refer to your heater's manual to troubleshoot thermistors, often affected by mineral and sediment build-up in older units.
  3. Required Maintenance: This is also an excellent time to perform any recommended maintenance, as outlined in your heater's user manual, to prevent future issues.

Replacing Faulty Heating Elements

If your heating elements show an OHMs reading outside of the 6 to 10 range, they'll need to be replaced. Common issues necessitating replacement include air pockets, mineral and sediment build-up, or freeze damage. Before replacing, physically inspect the elements for any visible signs of damage.

Maintenance Is Key

Regular maintenance, as specified by your EcoSmart, Eemax, or Rheem model's guidelines, can significantly prolong the life of your water heater and its components. This includes descaling to prevent mineral build-up, checking for corrosion or leaks, and ensuring the system's overall health.


Troubleshooting and maintaining the heating elements of your electric tankless water heater is crucial for optimal performance. By following the steps outlined above, you can ensure your water heater remains in excellent working condition, providing your home with efficient and consistent hot water. Whether you're a seasoned DIYer or new to home maintenance, these tips will help you keep your water heater running smoothly for years to come.

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