Have you ever noticed a significant drop in water temperature supplied by the water heater? Your home requires a hot water system to help you carry out specific house chores. But it can be frustrating when the system delivers only lukewarm water that can’t serve your daily intended activities. And it sucks.
However, while many factors affect the proper functioning of the water heater, a damaged element is one of the main causes. Even though qualified home electricians can fix the problem for you, hiring them will cost you some dollars. Therefore, you need to understand how to test the water heater element then replace the defective parts.
Here is a step-by-step DIY guide on how to test water elements using a digital multimeter.
What you’ll need
- Digital multimeter
- Safety goggles
- Hand gloves
Causes of a faulty water heater element
- Mineral Accumulation
Water heater elements experience a reduced working life due to the processes they undergo to produce hot water. But sometimes mineral deposits in the water tends to damage them.
A proper measure to do is switching off the water heater then regularly flush the water heater every year.
- Trapped Air Pockets
Water heater elements should be operated when immersed inside water. The heat produced by an element can end up burning through its copper when not moved to the water.
Therefore, you must bleed a line inside the water to remove the trapped sediments and air inside the tank. If you don’t do this, the trapped air ‘Air Pockets’ burns the upper element since it’s not immersed inside water.
- Malfunctioning Thermostat
A thermostat helps in alerting you when to heat the water on different water temperature levels. Immediately the temperature moves past the normal; the thermostat’s high limit switch gets triggered, thus shutting it off.
A faulty thermostat doesn’t control the heat distributed to the water heater element, ending up burning the element.
- Bad Wire Connection
Water heater elements get power from heavy gauge wires. They may stop functioning when the wire slips of the terminal due to poor connection. Poor connection leads to problems like arcing.
Additionally, it can burn due to sudden voltage increase due to lightning or power surge. Each element has a voltage rating, and any voltage past the required might burn the element.
Steps On How to Test Water Heater Element
Step 1: Start by Disconnecting from The Power Source.
This is an essential step when you think of testing the water heater element. Find the circuit breaker located at the central electrical panel linking your water heater. Find this at the metal box fixed on the wall.
In most homes, each breaker indicates the gadget it powers. Therefore, start by looking for the “water heater” breaker, then power it off. When you aren’t sure about the breaker that supplies power to your water heater, power off the whole system to ensure you are safe.
Step 2: Open The Metal Box Cover
After switching off the breaker, flip the metal cover for the opened box. Here, you’ll find panels held securely with screws to the water heater’s side.
Many water heaters are designed with up to two panels depending on their sizes. Loosen the metal plate with a Phillips head screwdriver. Make sure the screws don’t fall to squeezed places in your house.
Step 3: Remove The Insulation.
Water heaters are designed with a fiberglass or cellulose insulation beneath the metal cover. Open the insulation, then place it aside. As you do this, use safety goggles and gloves, then check on the thermostat to confirm whether it has a plastic cover.
Get off the tab to disengage the plastic cover of the thermostat. This is an optional step since many thermostats don’t have a removable plastic cover.
Step 4: Again, Confirm Whether the Power Is Off
Make sure you double-check to be sure whether the power is disconnected. Use a noncontact voltage detector neat the wire that connects the thermostat and the element.
Flashes of light or a beeping sound from the voltage detector shows you that the water heater has power. Make sure that the power is disconnected before you proceed with the work.
Step 5: Find The Ends of the Elements in The Open Panel.
Based on the size of your house, the water heater might have up to two elements. Sometimes you may fail to see the elements themselves since they are found deep on the open panel of the water heater.
But you can only see their endpoints. A water heater element is about 1-inch-long, and it’s fixed on a plastic plate using screws.
Step 6: Take The Reading of the Water Heater Element.
Make sure you set the multimeter dial to Rx1k being the lowest, that is, resistance times 1000Ω. After that, check closely on the lower side of the water heater tank. Here, you’ll find the inscribed ohms and wattage.
When your water heater is at 3500-watt, the multimeter reads 16Ω, and at 4,500-watts, it reads between 12 – 13Ω. Water heaters having 5,500-watt element, you find between 10-11Ω.
Step 7: Read The Water Heater Element Using a Digital Multimeter.
Put one probe on the screw fixed on the element. Do this by unraveling the loosely attached end of the metal element. The element doesn’t have a terminal. Therefore, you don’t have to be worried about which one to start with.
Make sure that you are only testing the element. Don’t test any other electrical part connected to the elements. Fix the multimeter prongs on the upper side of the element screw.
After that, check the multimeter readings then confirm whether it correlates to the ones specified. When the resistance doesn’t read at all, or it’s too low like 1Ω, that means the element needs replacement.
Step 8: Fix Back Disconnected Parts
After replacing the faulty water heater element, return the wire to the water heater element’s surface. After that, cover the panel, then use plastic to cover its thermostat. After that, tighten the replace wire, then fix back the screws.
Return the insulation, then switch on the circuit breaker. After that, wait for some minutes for the water to heat up.
How to Test Water Heater Element Thermostat
To check for faults on the thermostat, you must have a screwdriver and a multimeter. The following steps explain how to test a water heater element thermostat using a multimeter.
- Check whether the thermostat terminals have power. When there’s power, you’ll have a reading of 240V on the 1st and 3rd terminals. In case there’s no reading, check on the power source. Furthermore, you can also have a look for current on the high limit switch.
- Next, disconnect the lower thermostat by rotating the dial to the least setting. After that, turn up the temperature on the upper thermostat to check for errors.
- Put the multimeter prongs on the first terminal and the blue wire on the heating element. Doing this will assist you in detecting whether power is moving from the blue wire and the upper part of the heating element.
- When the multimeter reads 240V, then power is on the setup. After that, put the prongs on the second terminal and the blue wire. When there’s no reading, then the thermostat has a problem.
- After that, move to the heater’ lower thermostat. Then dial on the top thermostat to the minimum setting. As you do this, make sure you set the other thermostat to the highest level.
- With that done, move back to the first terminal and the red wire on the lower heating element. Put the probe on the two to check whether there’s power. Once it reads 240V, then power is there.
- Finally, position the probes on the red wire and the second terminal of the lower heating element. When there’s no reading, you must remove the thermostat and replace it with a new one.
Water heaters come with a thermostat like a tankless water heater. The good news is, testing and replacing a damaged thermostat only needs a few tools like screwdrivers and a multimeter—no need for too much skills to test the water heater element.