How To Test Your Hot Water Heater Elements With A Multimeter

Your hot water heater plays a vital role in whether or not you can enjoy your home plumbing system to the fullest. Anyone who's had to take an ice-cold shower before work due to a badly leaking tank has experienced this first-hand. One of the most common issues that homeowners experience is an inability to make hot water--this is usually related to a bad element. If you know how to use a multimeter, you can easily test the elements right at home in just a few short, easy steps. Follow this easy-to-understand guide to start the process.


Firstly, if you are at all uncomfortable with any part of the process, stop and call in a contractor instead. Testing with a multimeter is safe if done correctly, but it's important that you have a basic understanding of their operation.

Secondly, always make sure that the breaker to your hot water heater is in the off position within your fuse box. Do not proceed until you are sure that this step has been completed. If you aren't 100 percent sure that you have the right breaker, shut down the main breaker and remove the electrical current from your entire house.

You will also need:

  • A working multimeter
  • A screwdriver
  • Safety goggles
  • Workman's gloves

Locating and Removing the Panel

Your hot water heater will have either one or two panels on the side, depending on its size. Most have two, one situated at the top and one situated at the bottom. Each of these is connected to one of the elements, so you'll need to remove these panels before the elements can be tested.

Locate the screws in each panel, and use the appropriate screwdriver to loosen and remove them. Place them in a secure location, like in a small bowl on a table. Pull the panels away to expose the insulation underneath.

This is where you'll need your gloves and goggles--insulation can damage both skin and eyes. Make sure you are wearing them, and then gently pry the insulation away. This will expose another set of screws and a black and red wiring system.

Note: in older systems, one wire may be yellow instead of red.

Set Up Your Multimeter

Turn on your multimeter and set the dial to the OHMS setting. This is usually represented as the Ω symbol.

Tip: Make sure your multimeter is functioning correctly before you use it to test your hot water heater, or you may see false results. For best results, use a fresh battery and touch the two leads together briefly after setting it to OHMS. If the LED screen shows 0.0, you know it's working.


Locate the screws that hold the black, red or yellow wires in place on each interior panel. These are the leads you'll be testing--the other screws don't hold current, they simply keep the panel in place. You'll know you have the right screws if you can trace the wire directly to them.

Next, touch each red and black lead on your multimeter to both wired screws. Check the LCD screen on the device to see if a reading comes up.

Any reading other than 0.0 is proof that the element is at least partially working, although this doesn't fully rule out issues. If your multimeter does happen to read 0.0, then you can stop here and focus on replacing that element.

Repeat this step for the second panel if you have one.

An Additional Helpful Step

This step isn't always necessary, but it can help if you still aren't sure whether there's a problem. 

Unscrew each of the wired screws to loosen the wires, and gently but firmly pull them away from the screw itself. Carefully look over each one, taking care to watch for melted wire cover, heavy tarnish, or blackened areas.

Should you find anything but clean, even wire, it may be the wires themselves that have shorted out or become faulty. If this is the case, you'll need a contractor to come in and re-wire your hot water heater. Many people choose to simply replace versus repair at this point as one of the most common causes for this is water leakage around the panel.

There's nothing better than a long, hot shower first thing in the morning. As a homeowner, you know that hot water is necessary for everything from cooking to cleaning. When issues with hot water occur, it's important to ensure that the heater itself is working correctly. For questions about this process or to gain assistance with testing, contact a plumber at a place like A Absolute Plumbing & Heating today.