How to Test an Electric Water Heater Element with a Multimeter (and without)

If your electric water heater is not heating or is running out of hot water fast, you might have a problem with the heating element(s).

But don't worry. This article will help you diagnose the problem by explaining how to test an electric water heater element with and without a multimeter.

It is important to note that the number of heating elements and thermostats in your heating device may vary. Depending on your specific setup, you may have either one or two heating elements, as well as one or two thermostats. Therefore, you will need to check either one or both elements accordingly.

How to test an electric water heater element for continuity: DIY tips

Here, we will show you how to test an electric water heater element and diagnose a bad element. This test can also detect issues such as: why there is no hot water, or hot water is not hot enough.

When testing the heating elements, we mainly perform the continuity test, which shows us whether there is an obstruction in the electrical element or not. That means if there is continuity, the part is good, and the electricity can flow through the element without disruptions.

If there is no continuity, the element has failed the test because it is broken and should be replaced. And if you are still trying to figure out where the problem is, this article can tell you if your heating element is bad.

The best way to test a heating element is to use a device called a multimeter, whether manual (analog) or digital.

By using this instrument, and in addition to continuity check, the element test will show you how much resistance is there in a closed electrical current.

You can also test water heater elements without a multimeter, using a continuity tester or ohmmeter.

Things you need

• Screwdriver
• Multimeter
• Non-contact voltage tester
• Ohmmeter / continuity tester
• Gloves

Using manual (analog) and digital multimeters for testing

Before performing the test, ensure the multimeter's dial is in the lowest OHM resistance settings.

Also, you might have to calibrate the meter so it can read precisely.

Most multimeters come with two plastic probes (red and black) and metal leads at each end used to make contact. Use the plastic tubular sections for handling.

Touch the metal leads together with the dial in the OHM resistance mode. While the connection is made, check the multimeter and see if the needle of your manual (analog) manometer is in the zero position. If it is not, make the adjustments.

Setting a digital multimeter for testing is similar to the manual type, but instead of checking the needle position, you have a large digital screen, or you might have the option to set the dial to tone mode.

How to test a water heater element with a multimeter: Instructions

• Locate an electrical panel with the circuit breakers and flip the breaker to the off position.
• Shut off the power supply to the water heater as well.
• Locate an access panel found at the bottom of the electric water heater (see the picture).
• Remove the metal plate.
• Remove the insulation to get access to the element and its thermostat. You might have to remove the plastic cover as well.
• Double-check that there is no electrical current, either using a multimeter or a non-contact voltage detector if you have one. Your instrument of choice should not show any voltage, illuminate, or beep.
• Loosen the screw with the screwdriver and remove the electrical wires.
• Measure the resistance between the two screw terminals of the heating element. Use one of the multimeter probe leads and touch one of the screw terminals of the heating element and the other screw terminal with the other instrument's metal lead.

If the heating elements are in good working condition, your multimeter should show between 10 and 30 ohms (depending on the voltage). This indicates continuity.

If there is no reading or the reading value is very low, your heating element has no continuity, which is not good.

One of the reasons why there is no continuity is that the element has shorted out.

And here is the test to confirm that:

• Touch the heating element's terminal (screw) with the one metal lead and a metal tank or element's flange with the other.
• If the multimeter shows reading, or a tester beeps or illuminates, it is an indication that there is a short circuit within the heating element.
• The solution for this problem is to replace a broken heating element.

How to test a water heater element without a multimeter

Did you know that you can test a water heater element without a multimeter?

You can simply use an ohmmeter or a continuity tester for the continuity test.

The procedure is the same. Note that the multimeter is a more advanced and multi-purpose instrument that can also be used as an ohmmeter, continuity tester, voltmeter, and ammeter.

So, when both tester leads or alligator clamps are placed on each element's screws, the continuity tester will illuminate or make a beeping sound if the element is in good working condition.

An ohmmeter helps you perform a resistance test which is more accurate than the above continuity test. It provides you with specific values, which you then compare against the element's specs. If you need information about the resistance values, keep reading to find out how to calculate them.

You can use both instruments to test if there is a short circuit within the heating elements.

You need to connect the continuity tester leads or alligator clips to one element screw and the other to the element flange. If the tester illuminates or makes a beep, there is a short circuit inside your water heater element, and it must be replaced.

How much resistance should a heating element have?

While we mentioned the recommended range of resistance before, you can calculate it as long as you have the correct info.

In order to calculate the resistance of the heating element, we should use the formula: R=V*V/P; where R is the resistance, V is the voltage, and P is the power of the heating element.

If the heating element has a power of 3,500 W and the voltage is 220V, using the above formula will get us the following:

R= (220*220)/3,500=14 Ohms.

So, an element with 3500 watts will give us 14 Ohms, while an element with 5500 watts will show 9 Ohms (for the voltage of 220 volts).

As we mentioned, an electric water heater should have between 10 and 16 Ohms of resistance (plus/minus a few Ohms). Resistance depends on the unit's size, power of the heating elements, and voltage (110 volts is standard in North America and 220 volts in Europe).

What's next

Testing an electric water heating element for a potential problems is easy and doesn't require special skills and tools (except a multimeter or other testers).

So, what's next, you will ask?

Well, that depends on whether your testing showed a problem or the resistance is within the water heater specifications.

If your water heater element is broken (malfunctions), use this article to see how to replace it.

If your heating element is good, you need to dig deeper and find the cause of the problem. You can use this comprehensive guide to get more information on troubleshooting and repairing electric water heaters.