Simple Guide: How to Check Heating Element in Water Heater Safely

Learning how to check heating element in water heater is useful when an electric tank runs out of hot water or heats only partly. Most electric water heaters have two elements, an upper and a lower, and each is controlled by its own thermostat. Testing them with a multimeter shows which element has failed before you buy a part.

Knowing how to check heating element in water heater tanks saves a wasted trip for a part.

How electric water heater elements work

An element is a metal tube with a resistive wire inside. When the thermostat calls for heat and the element has power, the wire heats up and warms the water around it. The upper element heats the top of the tank first, and the lower element heats the bottom. When one element fails, the water above or below it may stay cold, which tells you which element to check.

Quick facts: how to check heating element in water heater

Quick facts
Check first	Power is off at the breaker and the tank is cool to the touch
Test	Continuity or resistance across each element's terminals with a multimeter
Good reading	A low, steady resistance; an open reading means the element has failed
Call a technician if	The wiring is burned, the tank leaks, or you are unsure of the test

Step 1: cut the power

Turn off the breaker that feeds the water heater, and confirm the power is off with a non-contact voltage tester at the terminals. Electric heaters run at 240 volts, which can be dangerous, so do not skip this step. Let the water cool before you work near the element.

Step 2: remove the access panels

Remove the insulated cover over each thermostat and element. Behind the cover are the wires and the thermostat. Note how the wires are connected, or use tape to label them. Keep the insulation on the wires intact.

Step 3: test each element

Disconnect the two wires from one element. Set the multimeter to resistance and measure across the element's two terminals. A working element reads a low, steady value that the label lists. An open or very high reading means the element has failed. Repeat for the other element.

Step 4: check the thermostat and reconnect

Test the thermostat for continuity with the power still off, and check that the setting dial works. If the elements and thermostat test good, the fault is probably elsewhere. Reconnect the wires, replace the covers and restore the breaker to test the heater.

Safety with an electric water heater

Always turn off the breaker before opening any cover, and test for voltage before touching the terminals. Water near electrical parts can cause a shock, so keep the area dry. If the tank leaks or the wiring looks burned, stop and call a professional.

When to replace an element

Replace an element that tests open or shows burned or corroded terminals. Before you order a replacement, confirm the test result, since how to check heating element in water heater correctly is what prevents the wrong part being bought. Use a replacement that matches the wattage and voltage on the label, and fit the gasket or seal it uses. Replacing both elements at once is common when the tank is older, since the other element may fail soon.

When to call a professional

Call a licensed plumber or electrician if the wiring is damaged, if you are unsure of the test, or if the tank leaks around the element. A professional can also check the thermostat and the anode rod, which affect how long the heater lasts.

Keeping the elements working

Flush the tank yearly to remove sediment, which can cover the elements and cause them to overheat. Set the temperature at a reasonable level and check the thermostat if the water seems too hot or too cold.

How to check heating element in water heater: a safe test

Before you start, turn off the power at the breaker and confirm that the water is cold at the tap. Electric water heaters use two elements, an upper and a lower, and each needs its own test. Learning how to check heating element in water heater tanks correctly means working through them in order.

Reading the multimeter

Disconnect the wires from the element terminals, then measure the resistance across them with a multimeter. Compare the reading with the value calculated from the element's rating. A 4,500-watt element on a 240-volt circuit should read about 12.8 ohms, since resistance equals voltage squared divided by wattage. Knowing how to check heating element in water heater readings this way gives a clear answer. A reading close to zero can mean a short, and a very high or open reading usually means a broken element.

When the thermostat is the problem

A faulty thermostat can stop an element from receiving power even when the element is good. Check the thermostat as part of how to check heating element in water heater problems. With the power off, test the thermostat for continuity, and replace it if the contacts do not close when the water is cold.

Safety notes

Water heater elements are heavy, and the threads can be stiff. Use the right socket, and keep the gasket clean when you refit the element. If you are not confident working with 240-volt wiring, call a licensed electrician.

Record the readings

Write down the reading for each element, the date and the rated wattage. A record makes it easier to see whether a how to check heating element in water heater test changes over time, and a clear note helps when you call a technician.

Related reading

• Simple Gas vs Electric Water Heater: Which Suits Your Home
• How to Reset a Water Heater: Electric, Gas and Tankless
• How to Flush a Water Heater: Step-by-Step, Safely
• Water Heater Replacement Cost: What Drives the Price

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