How To Tell if Your Water Heater Element is Bad and What to Do?
DIY Water Heater Testing and Repair Tips

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If your electric water heater is not producing enough hot water or not at all, you might have a broken heating element. A water heater failure is the main inconvenience because there will be no hot water for washing clothes, dishes, and showers.

Before you call a plumber, you might want to read this article and learn how to diagnose if your water heater element is bad and also to test and replace it yourself.

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What is a water heating element, and how does it work?

Electric heating elements found in electric water heaters and heat pumps are immersion-type elements designed to heat water when energized with electricity.

Most residential electric water heaters are equipped with one or two elements and designated thermostats to control each element and hot water temperature.

Thermostats are surface mounted, and homeowners can manually adjust the temperature using a screwdriver.

In addition to that, there is a high limit switch, a safety device that regulates the electrical current flowing through the heating elements, therefore protecting the unit from high temperatures and potential damages.

Tip: If you need any electrical work done on your heater, including thermostats and heating elements, it is recommended to contact a licensed electrician, because dealing with the high voltage is dangerous.

If you want to replace the elements yourself, make sure to shut down the power on the circuit breaker box and use the multimeter or voltage tester to double-check that the power is off.

Signs of a bad water heater element and how to diagnose a problem

The common causes of the electric water heater trouble are when one or both heating elements are burned out, including a tripped circuit and a blown fuse. These will lead you to no hot water problems, slow water heating, or a situation when hot water runs out fast.

But, don't worry.

Testing and replacing heating elements is an easy DIY project and doesn't cost much (approximately $20 for the element). You just need a few tools such as a screwdriver, pliers, and voltage tester.

How to test a water heater element without a multimeter

To see which heating element is bad, just turn on the hot water tap at the sink and check the temperature.

For this test, you won't need a multimeter.

If the water is hot but only for a short period of time and then becomes cold, your bottom heating element is broken.

When only the upper element is heating, a small portion of water at the top becomes hot, so it runs out fast. The rest of the water is still cold because the bottom element is dead.

In the case when both elements are defective, there will be no hot water in any part of the tank.

In the case of the water heaters with the dual heating elements, the thermostat attached to the upper element controls the power to the lower one, so if the upper element is broken, the lower one won't work as well; no matter if it is good or not.

How to diagnose a problem with a multimeter in a few simple steps

You can also use a multimeter and test both heating elements to confirm which one is good and which is bad.

This is how:

  • Remove the metal covers and insulation that covers the heating elements.
  • Disconnect the wires.
  • Check the elements for continuity/resistance. Touch each screw with the multimeter probes and if the continuity is broken or resistance (in ohms) is zero or extremely high, the heating element is bad and needs to be replaced. If you use a continuity tester,  and if the element is good the light on the tester will light up or buzz (if available).
  • Check also if the element is shorted. If you use a tester, put one probe on the screw and touch with the other on a metal part of the water heater (tank, for example). Do the same thing with the other screw. If the light comes on, there is a short and you need to replace an element.

If your water heater is equipped with the 4500-watt heating element, the multimeter should show around 12-13 ohms, when set to resistance mode.

Note that even with the elements burned out you will still have some hot or lukewarm water available, depending on when was the last time when heating occurred.

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What to do if your water heater trips a breaker

Your water heater might trip due to the following reasons:

  • Faulty thermostat(s)
  • Broken heating elements
  • Loose or faulty connections

If your water heater keeps tripping the breaker, check both heating elements, thermostats, and electrical wiring.

Also, try resetting the heater. Turn off the water heater at the breaker and locate the red reset button above the upper thermostat. Press the reset button and see what happens. The reset button is also known as the high-temperature cutoff switch.

If it trips and won't reset, one of the thermostats might be broken.

If it solves the problem but happens, again and again, check your heating elements.

What else can cause bad or low performing heating elements

Dry-fired elements

Every time you resume the power after the service, ensure that your storage tank is full of water; otherwise, heating elements can be exposed to air and lead to dry fire and damage.

Limescale build-up

Due to hard water, heating elements can be subjected to sediment build-up, resulting in lower efficiency or even breaking when heavily covered in limescale and exposed to high temperatures.

Voltage spikes, water exposure and mechanical stress

Heating elements can also break when a voltage surge occurs due to weather, such as lightning or even a power surge.

Water leaking is not good, and if heating elements get in touch with water, they can break.

Vibration and mechanical stress are also not good. Check your heating elements for any signs of deformation. Any breakage on the inner filament will show no continuity when you test the element. In such a case, replace an element.

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Get free quotes today!

Contact a Plumber!

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