How to Test Water Heater Element Using a Digital Multimeter?

Now to understand the testing of a water heater element, first, let’s have a sneak peek about how the apparatus basically functions. You see, there are one to two elements that work for heating the tank’s water. When suddenly, the water stops getting hot it should mean that upper element of a double element heater is having issues.

Things can be a little different too. The heater may produce some hot water. But it’s not nearly as much as it usually does. This also means a lower element issue.

To figure out the whole thing, one needs to learn about how to test water heater element and apply it. Today we would be basically discussing that.

How to Test Water Heater Element: Tools to Tutorial.

So, the guide will be kept super simple. Don’t worry, you are going to need bare minimum tools for this.

Just get some regular hand gloves and safety goggles for your personal protection. And then bring a screwdriver and digital multimeter. The last one is going to play as a protagonist of this whole concept. Keep on Reading!

How to Test Water Heater Element

Power Source Needs to Stop Sourcing.

Okay so let’s start with the most crucial step that relates directly to your safety. And it’s about locating the central electric panel’s circuit breaker. This is basically where heater should connect for the power source. You should find it within the wall attached metal box.

Usually electricians will mark breakers with a nametag referring to the gadget it powers. In that case, you should look for a tag that says hot water heater or similar synonyms. Turn this off. If you are not sure however, better turn off the entire power source for now.

Get the Metal Box Cover Out.

Open the box by filliping its metal cover. Now on the side to your water heater, there should be panels held nicely using screws. Depending on what sized heater you use, there can be one or more panels here.

Use the screwdriver and unscrew this metal plate. Be very gradual and careful as well. You don’t want to lose those tiny screws by accidentally dropping them below. It’s going to be a big pain finding them if you do.

Also, make sure you wrap the screws with a tissue paper to store them aside. Trust me when I say this step is very critical. I’ve seen many stories of screws getting misplaced and inviting a whole new problem on sight.

Insulation Comes Off Next.

Depending on how old your heater is, there can be a bit different looking insulation beneath the metal cover. It could be a layer of cellulose or fiberglass in most cases. You want to disengage the insulation next. Keep it aside carefully, don’t misplace them.

You should be wearing gloves and goggles during this phase. Look for a plastic cover within the thermostat. Pull the tab out. This should detach the plastic cover. Some models may not have this plastic cover, so if you can’t find any it’s okay. Move ahead…

Double Check the Disconnection.

There should be a wire that connects both thermostats and elements. Place a noncontact voltage detector close to this wire. If you hear a beeping sound or it flashes light, the power source is still supplying electricity. Go back to the power source and make sure to turn the thing off. It must disconnect for you to proceed.

Element’s Endpoint Detection.

Inside the water heater’s open panel, elements are going to extend really deep. To the point that you can’t really see the elements themselves. However, the endpoints should be visible. Usually the element is one inch long. There should be a plastic plate attached using screws for this thing.

Water Heater Elements Reading Check.

You need to set the dial of multimeter to its lowest. In other words, it should be on Rx1k. this basically means resistance times a thousand ohms. Now have a look at the water heater’s base part.

The inscribed wattage and ohms must be visible here. In case of a 3500 watts water heater, the reading should be 16 Ω. On the other hand, there should be 12-13Ω reading for a 4500 watts heater. The 5500 watts heater should have a 10-11Ω reading here.

Digital Multimeter Reading Check.

The screw that sticks with elements face, you need to place on probe of digital multimeter right here. Just unravel the metal elements loose end to do this. There should be no terminal in the water heater element. So, there’s no need to worry about which one to test first or last.

But do make sure you are actually testing the element only. There should be no another electrical component tested along. You really want to be extra careful to connect prongs of multimeter to the element screw’s tip.

The readings you get should be similar to what I told you during last section. However, if you witness a very low reading here for instance one ohm, then believe it’s faulty. There may be a chance of no reading at all. The conclusion is still the same, faulty. And you need to think about replacement if these are the cases.

Using the same method, also check other elements if there is any. If any out of these elements are faulty, go for a replacement.

Get Everything Back to Its Place.

The wires you disconnected will go back to heater element’s surface. You also need to cover the panel which is exposed. Let the thermostat plastic cover go to its original place too. Complete all required replacement for wires and tighten those loosened screws after reinstalling them.

Let the insulation also get back on its track. And finally turn the circuit breaker on. Wait for a couple or more minutes. And your heater should start working since you have replaced the elements.

You Are Done!

And that was a simple checkup tutorial on how to test water heater element. The next time you get into a situation of a disturbing water heating incident, go for the checkup yourself. Just be sure to not get too hasty about the whole thing. You want to take your time and really dig into the problems. And if there is one, a water heater element replacement should come next.

Have a Nice Day!

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