How to Replace a Bad Electric Water Heater Heating Element
InspectAPedia® -
Electric Water heaters: how to inspect, test, adjust, repair a water heater
How to find & identify the parts & controls on an electric water heater
How to test and repair an electric hot water heater
Test procedure for electric water heater high limit cutoff thermostat switch
Test procedures for electric water heater heating elements
How to replace and wire-up the heating element on an electric water heater
Guide to inspection of electric water heaters
No Hot water? how to get more hot water flow, quantity, performance from your water heater
Questions & answers about how to remove and replace a burned out heating element in an electric water heater
Electric water heater heating element replacement guide: how to remove and replace a bad electric hot water heater heating element or electrode - details.
InspectAPedia offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/Contact.htm.
Having completed testing electric water heater components in the previous article, This article explains how to replace a bad electric water heater heating element. This series of articles describes how to inspect, operate, diagnose, and repair electric hot water heaters. Reproduction of this web page electronically at other websites is prohibited.
If you cannot find information you need here or if you have comments, questions, suggestions for inspecting and diagnosing water heaters Contact Us.
How to Replace a Burned Out Electric Water Heating Element
The sketch at left of the parts surrounding an electric water heater heating element is modified from illustrations provided by American Water Heater Co. [1] These parts are identified (click to see an enlarged sketch)in order as shown in the sketch as
1. Access door covering the heating element, typically held in place by two sheet metal screws (blue)
18. insulation (gray)
2. plastic cover over the thermostat assembly (green)
3. Thermostat assembly (upper)
5. Electric heating element (red arrow - this is what you are replacing)
6. Electric heating element gasket (purple arrow)
No number: yellow arrow points to the heating element mounting location. Clean this area and its threads during heater element replacement.
Watch out: as manufacturers of water heaters point out, you can be killed or seriously injured if you do not follow instructions provided by the water heater manufacturer and described in the water heater's instalallation, usage, and maintenance manual. Below we describe the general procedure for replacing and wiring electric water heater heating elements. Be sure you consult your individual water heater's installation guide for details.
Turn off electrical power to the water heater. Failure to turn off electrical power can result in fatal electric shock, and it will certainly burn up any water heater elements that are still good when you drain the tank.
Watch out:
Do not turn elecrical power back on until the tank has been repaired (elements replaced, no leaks) and the hot water tank has been re-filled with water.
Close the cold water supply valve that feeds water into the water heater tank and
Drain the hot water tank tank by connecting a hose to and opening the drain valve located near the tank bottom. See How to Drain a Hot Water Tank for details. If this drain valve is damaged, leaky, or in poor condition, we recommend that you replace it - it's not a costly part. Be sure to use teflon tape or pipe dope on any threaded plumbing parts you are replacing. Leaks are not permitted.
Remove the access covers over the heating elements. You will have to fold insulation outwards, or if the insulation is plastic foam as in our illustration, just remove the insulating block and set it aside.
Remove a plastic thermostat cover found under this insulation (gray cover in our photo) - that protects the thermostat electrical connectors from touching the water heater thermostat cover, and then disconnect the electrical wires connected to the water heater element that is going to be replaced.
Remove the heating element. Some water heater elements screw into a large threaded opening on the water tank (as in our photo at left). (We use a large 1.5" diameter socket wrench to get these elements out as it's easier than bumping around with a wrench.
Turn the screw-in heating element counter-clockwise "leftie-loosie" to remove it. ) Other electric water heater elements are held in place by a steel plate and several smaller bolts. Often you will see that the old heating element was in trouble - sometimes we see that it has partly disintegrated.
Other electric water heater elements may be secured with a bracket, shown in our sketch at left.
Remove the sealing gasket that prevented leaks between the heating element face and the water heater tank face.
Buy a replacement electric water heater element: This is a great time to take your old heating element for a ride - to the hardware store to buy a replacement water heater element of the same voltage, wattage, and length. That way you can be sure the new heating element will fit. The "length" determines how far the heater element sticks into the water tank.
Size matters.
An electric water heater element that is too long may not fit or it may contact the dip tube or other water heater components - an unsafe condition. The sketch of an electric water heater element ready for installation is provided by American Water Heater [1].
Clean the threaded opening (we use a toothbrush) and if you're replacing the lower element, this may be an opportunity to remove scale from the tank bottom. (See scale removal details at at WATER HEATER NOISES)
Prepare the new heating element for installation: use teflon pipe dope or similar pipe thread sealant rated for hot water, applying it to the opening threads and to the threads on the new water heater element.
Screw in or mount the new water heater element. Turn the heating element clockwise using the same socket wrench you bought earlier (no one has one, right?) Clockwise = to the right "rightie - tightie". Wipe off any water droplets before reinstalling the new heating element - that will make it easy to check for leaks when you have re-filled the water tank.
Watch out: When installing the new water heater element, be sure to replace this gasket with a new one that comes with your new heating element - otherwise the heater will leak. Clean the water heater tank face where the new gasket will sit before installing the new heating element.
Electric water heater thermostat and heating element wiring diagram
Be sure that any electrical wiring that you disturb or disconnect is reconnected as it was originally. We label parts or make a sketch to avoid confusion later on. Check for proper water heater thermostat and heating element wiring connections by reviewing the installation manual that pertains to your water heater.
At far left we show a typical wiring diagram for a two-element electric water heater at which both heating elements operate simultaneously.
At left we show the water heater thermostat and element wiring details from a Plumber's Pack Water Heater Repair Kit using Thermo-o-Disc thermostats.
This electric water heater repair kit includes two electrodes and the upper and lower thermostats as well as replacement plastic covers for those devices.
The kit fits most models of electric water heaters made by American Water Heaters, A O Smith, Bradford White, Craftsmaster, General Electric or GE water heaters, GS Wood (some models), Kenmore, Lochinvar, Maytag, Mor-Flo, Reliance, Rheem, Richmond, Ruud, Sears and State - in other words many major water heater brands.
[Click for an enlarged view of either water heater element wiring illustration.]
But your electric water heater wiring may differ in that it may have only one heating element, or the two-element heater may operate the heaters individually (non-simultaneous), or your unit could be a 120V heater (less common at residential buidings) or even a three-phase installation (more likely at larger heaters and commercial installations). [1]
Continuing with the steps in replacing the heating element for a typical electric water heater:
Reconnect and secure the electrical wires to the new heater element terminals. No, it does not matter which wire goes to which heating elementy terminal in this case - electricity can flow in either direction. [Other electrical connections DO matter very much, as we warn above.]
But we recommend that you re-connect the electrical wires exactly as they were in the original water heater element installation - that will minimize bending and forcing wires into a new position in the heater, thus minimizing chances of breaking a wire or damaging its insulation. Remember to replace the plastic cover that protects the wires and terminals before pushing the insulation back in place and then replacing the water heater element cover.
Close the water heater tank drain valve.
Re-fill the water tank with cold water. It will be easier and faster to fill the tank if you open the cold water inlet valve feeding the water heater and then open a nearby hot water faucet in the building until water flows freely out of that faucet.
Watch out: as American Water Heater and other manufacturers warn, if you turn on electrical power to the heating elements when they are not already immersed in water, the element will be destroyed! [1]
Check before leaks around the heating element before you continue.
Make sure that the water heater tank has completely filled with water by turning on hot water at a nearby faucet - you should feel water (cold of course) coming out of the faucet. Then it's OK to turn on electrical power to the water heater and allow it to re-heat.
Good luck! After waiting for the tank to heat up, possibly a half hour or so, you might have hot water now.
Questions & Answers regarding this article
Questions & answers about how to remove and replace a burned out heating element in an electric water heater.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
[1] "Residential Electric Water Heater Installation Instructions and Use & Care Guide", American Water Heater Co., October 2001, American Water Heater Co., Johnson City, TN, [manufacturer of residential & commercial water heaters, also manufacturer of Polaris/Commercial water heaters], Tel: 800-999-9515, web search 1/12/2012, original source: americanwaterheater.com/support/manuals/res-elect.pdf [copy on file]
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Mobile View
