How to Replace the Heating Element in an Electric Water Heater

Water heater
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  • 01 of 04

    How an Electric Water Heater Heating Element Works

    components of an electric water heater
    Electric Water Heating Elements. © 2010 Home-Cost.com


    Unlike gas water heaters that have gas burners to heat the water, electric water heaters rely upon an upper and lower pair of metal heating elements. These heating elements are made of metal and get hot from electrical resistance, similar to what you would find in an electric cooking range.

    In a water heater the cold incoming water is not delivered at the top of the tank, but rather near the bottom through a dip tube as seen in the diagram Anatomy of a Water Heater.

    As a result of a cold water...MORE supply coming in near the bottom of the tank, the lower heating element is the workhorse of the electric water heater. The upper heating element really only contributes when there is a high hot water demand and only serves to heat water in the upper portion of the tank. A constant supply of lukewarm water during a shower is indicative of a defective upper heating element. Short duration hot water supply during a shower is indicative of a defective lower heating element. Replacement heating elements must be of the same style and voltage/wattage rating as the ones presently in the water heater.

    Continue to 2 of 4 below.
  • 02 of 04

    Testing a Water Heater Heating Element

    A plumber working in a water heater
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    To test an electric water heater heating element proceed as follows:

    • Use an electronic multimeter or multi-tester to test the heating elements in an electric water heater.
      Compare Prices Multimeter or Multi-Tester
    • Turn off power to the electric water heater at the main power panel. Do this by turning off the circuit breaker or fuse powering the heater.
    • Wait for the water heater to cool, this is very important because the heating elements operate off a thermostat and hot water in the tank will...MORE affect electrical flow to the heating elements.
    • Test for lukewarm to cool “hot” water by opening a hot water faucet and running the water until it is cool.
    • Remove the access cover panel and insulation covering the heating element terminal block. Fold the insulation outward and away from the heater element.
    • Loosen the screws holding the wires to each of the two terminal screws and remove the wires.
    • Test for proper functioning of the heating element by checking for an open or closed circuit (continuity) using the electronic multi-tester. Set the multi-tester to “Ohms” and connect the red lead to one terminal and the black lead to the other terminal on the heating element.
    • If the ohm reading is 0 on a digital multi-tester or if the needle reads infinity (does not move) using an analog dial, there is no flow of electricity through the element and it needs replacement.
    • If you get an ohm resistance value using the multi-tester, then the heating element itself is not bad. The problem may be the other heating element or the upper or lower heating unit thermostat.
    Continue to 3 of 4 below.
  • 03 of 04

    Heating Element Removal

    water heater elements
    Screw-in and Flange Type Heating Elements. © 2010 Home-Cost.com
    To remove the heating element proceed as follows:
    • Shut-off the electric power to the water heater at the main power panel. Do this by turning off the circuit breaker or fuse powering the heater.
    • Next, drain the electric water heater.
    • Remove the access cover panel and insulation covering the heating element terminal block. Fold the insulation outward and away from the heater element.
    • Remove the thermostat cover from the thermostat if necessary. Make sure to disengage the attachment point from the...MORE thermostat.
    • Loosen the screws holding the wires to each of the two terminal screws and remove the wires.
    • Remove a screw-in type heating element by turning the element counterclockwise with a 1-1/2 inch socket element removal wrench. Remove the existing gasket.
    • Remove a flange type heating element by removing the four screws holding the element in place. Remove the existing gasket.
    Continue to 4 of 4 below.
  • 04 of 04

    Heating Element Replacement

    Construction: Fixing a hot water heater
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    To replace the heating element proceed as follows:
    • Clean the area surrounding where the gasket fastens to the tank. It is good practice to remove and sediment at the bottom of the tank if you are replacing the bottom heating element.
    • Make sure the replacement element has the correct voltage and wattage rating. You can find this information on the flange or terminal block of the element or on the water heater’s data plate.
    • Properly place the new gasket onto the heating element and insert the...MORE assembly into the water heater tank. Tighten a screw-in type heating element by turning clockwise with the element socket wrench until secure.
    • Close the drain valve on the water heater.
    • Open the nearest hot water faucet to allow the tank to fill completely with water.
    • Keep the hot water faucet open for 3 minutes after obtaining a constant flow of water. This will purge the lines of any excess air and sediment.
    • Check for leaks around the element.
    • Connect the power wires to the electric heating element and make sure they are tight.
    • Replace the thermostat cover.
    • Replace the access cover panel.
    • Completely fill the water heater tank with water. This is critical because running electricity to heater elements that are not immersed in water will destroy the heating element.
    • Turn power to the water heater back on at the main power panel. Do this by turning on the circuit breaker or fuse powering the heater.