An electric water heater makes use of one or two heating elements to heat the water in the tank. In cases where water heater can no longer heat the water; the main reason could be the upper element is not working.
A water heater that produces less hot water than it should be is a sign of lower element issue.
If your water heater trips the circuit breaker, there is a possibility that the element has grounded and can cause an electrical short.
Below are the steps on how to test a water heater element using a Multimeter.
Things You Will Need
- Safety goggles
- Noncontact voltage detector
Steps on How to Test a Hot Water Heater Element
Before you start testing your heating element in your water heater, it is best to check the circuit breaker box first. You can find it either outside or inside your home. Most of the time the box is labeled so you will not have difficulties in finding it.
If you find the one for your water heater is flipped, then it means you need to reset it. However, if it happens several times, then maybe there is something wrong with the water heater that it causes the power to overload.
Now you can proceed on testing your water heater element.
Step#1 Turn Off the Breaker
Put off the breaker inside your main electrical panel that provides power to the heater. Many electric water heaters use a 30-amp double –pole circuit breaker.
Step#2 Remove the Screws from the Panels
On the side of the water heater, you will find the panels attached with screws. You will either have one or two panels, depending on the size of your water heater. Release them by removing the screws from the panel.
Step#3 Remove the insulation.
Once the side panels were removed, the insulation will be exposed. Remove it. The insulation is a closed-cell extruded polystyrene foam or fiberglass. When removing this, make sure you have put on your safety goggles and glove.
Step#4 Remove the Safety Cover
From the element face, pull the plastic safety cover. The cover usually snaps on and off the thermostat and element.
Step#5 Check if Electricity is Still Present
Connect a noncontact voltage detector to the cables attached to the element face, and into each cable attached to the thermostat. The voltage detector will produce a sound and the light flashes if there is still electricity present in the water heater.
Step#6 Take Note of the Element Wattage
To see the element wattage, you loosen the two-element screws. Then remove the wires underneath the screws. You will see the element wattage printed on the side of the element face.
Step#7 Use Multimeter to Measure
Get your multimeter then turn the dial to Rx1k (resistance times 1,000 ohms). With one of the multimeter probes touch the screws on the face of the element. Place the other probe on the other screw. A 3,500 –watt element should be able to measure 16 ohms in multimeter. The 4,500 – watt element should show result between 10 and 11 ohms. If in case the element does not register on the multimeter, then it’s time to replace it.
Step#8 Check if the Element is Grounded
Keep the probes on one of the screws on the element face. Let the other probe touch to any metal part of the water heater. The heater element is grounded if the multimeter needle moves, and it needs to be replaced. You must test both screws on the element face.
Step #9 Test the Element
Place the multimeter probes on each screw. Then place the remaining probe on the metal-based attached to the element where it enters the water heater. The needle on the face of the multimeter moves if the element is bad and needs to be replaced.
Step #10 Putting Back Together in Place
Return the wires to the water heater element face. Snap the plastic cover back on the thermostat and the element. Then reinstall the insulation and don’t forget to attach the panels to the water tank. Once everything is in place again, turn the breaker on.
Reminder: When working with anything that involves heat or electrical-based, make sure that it is completely turned off before you start working on it. You should unplug it from the power source or turn off the breaker panel. You should do both if you want to be sure. If dealing with the heating elements of the water heater, make sure that they are not warm. Allow two hours to pass if you just turned it off before handling it.
Understanding the Readings
If the water heater element has continuity, then you will see data showing up on your screen. You should get around 10 to 16 ohms.
In case the multimeter provides no results, it only means there is no continuity, and the electricity cannot get from one end to the other end. It indicates that the heating element requires replacement. The water heater will display on the outside what type of heating element is needed. If in case it is not indicated on the appliance, consult your user guide to find out what heating element is required.
Different kinds of multimeters will work perfectly well for the water heater test. Make sure that you invest in the one that will work well long-term and has a more extensive range of testing functionality.
Your water heater element is damaged due to old age and continuous use. Also, using hard water that is high in mineral content can result in a default element. The cause could be scale build-up on water heater elements that will lead to their demise. But before you replaced them, it is best to test the water heater element first using the multimeter. Follow the above steps on testing, and you will never be wrong.