How to Troubleshoot a Water Heater That Isn’t Working

By Lyle Weischwill | Aug. 04, 2023 12:59 pm PST

What causes an electric hot water heater to stop working?

A water heater is one of the most forgotten-about appliances in a home—until it quits working. Once there’s no hot water, the water heater instantly becomes the most important appliance most homeowners have, and no one will be happy until the water heater is fixed.

The most common problems with a water heater are funny smells, water that’s either not hot enough or too hot, or no hot water at all. The reasons for these problems vary, but you may be able to figure out the issue and repair your water heater yourself by following some basic troubleshooting steps.

Basic Water Heater Troubleshooting

A common problem for both electric and gas water heaters is the smell of rotten eggs. This is most often caused by the sacrificial anode rod. The anode rod prevents the tank from corroding. Certain water conditions cause a chemical reaction between the rod and water supply, forming hydrogen sulfide gas that dissolves in the tank. A less reactive aluminum alloy rod can be installed in the tank instead to prevent this rotten egg smell.

If the water temperature isn’t hot enough, or if the water is too hot, it may be the thermostat isn’t set to the right temperature. Adjust the thermostat to the desired comfort level—but to prevent scalding, don’t set it above 120 degrees. If the water temperature doesn’t adjust after waiting a half hour, you should probably have a repair technician take a look at it.

If you run out of hot water when using it, wait about 30 minutes and then check the water temperature again. If the water is hot after waiting, you may need a larger water heater.

If there’s no hot water, verify every faucet is affected. Occasionally, a hot water supply pipe to a faucet may become clogged with a buildup of sediment that restricts the flow of hot water - especially if the water pressure seems lower than normal when you turn the hot water on.

If only one faucet or the shower head is lacking hot water, the anti-scald device could be set too high. There could also be an issue with the faucet valve that mixes cold water with hot. You’ll most likely need to contact a plumber for help in any of these instances.

If there’s no hot water in any part of the house, follow the troubleshooting advice below to fix your electric water heater as soon as possible.

How to reset your electric water heater breaker

You may be able to restore the hot water supply simply by resetting the house circuit breaker for the water heater. A tripped circuit breaker is one of the top reasons a water heater stops heating. At the house breaker box, shut the hot water heater breaker off and then turn it back on. Give the water heater a half hour to heat up (if it’s working) and then check for hot water again

If you get hot water after resetting the breaker, and the breaker doesn’t trip again, you’ve fixed the problem.

If the water heater breaker trips again, then you should have a technician examine the water heater. The service technician will check the circuit breaker and electrical supply wiring for the water heater. A short in the supply wiring or a bad circuit breaker could be causing the breaker to trip. An internal failure such as a broken heating element can also cause the breaker to continue tripping.

If resetting the water heater circuit breaker doesn’t help at all, it’s most likely the problem with the water heater is something else.

Reset the High-Temperature Limit Switch

Electric water heaters have a high-temperature limit switch on the upper heating element. When the upper thermostat trips, the heating elements don’t get electrical power and the water heater won’t work.

This limit switch has a reset button. Pressing the reset button may allow the heating elements to get power so the water heater will work. Follow these steps to reset the high-temperature limit switch:

  1. Shut off the house circuit breaker for your water heater.

  2. Remove the upper heating element access panel to locate the high-temperature limit switch.

  3. Press the red button on the switch to reset it.

  4. Reinstall the heating element access panel.

  5. Reset the house circuit breaker for the water heater.

  6. After a half hour, check to see if the water heater is heating water normally.

If resetting the limit switch restores the hot water supply to your home, you’ll need to monitor your water temperature for overheating. The high-temperature limit switch tripped for a reason. You most likely have either a shorted heating element or defective thermostat causing the water to overheat. You’ll need to resolve overheating problems to prevent scalding. Water temperature should never exceed 120 degrees. If the water overheats after resetting the high-temperature limit switch, have a service technician diagnose and repair your water heater or follow the DIY troubleshooting tips in our Water Too Hot: Electric Water Heater Troubleshooting to resolve the problem.

Conduct Advanced DIY Water Heater Troubleshooting

If the water heater doesn’t work after resetting the high-temperature limit switch, then you’ll need to either conduct some advanced water heater troubleshooting or have a service technician determine the cause of the water heater failure.

Sears Technicians created a safe and highly-successful DIY advanced troubleshooting video to help you determine the cause of a water heating failure if you want to try to fix the problem yourself. Follow the advice in this video to find and fix the cause of the heating failure on your own:

The video begins with the basic troubleshooting described above. It then goes on to guide you through checking water heater components to safely find the cause of the problem.

If you get to a point in the video where you’re not completely confident you can safely continue, schedule a service technician to diagnose and repair the water heater.

The DIY water heater troubleshooting shown in the above video differs from the diagnosis techniques that service technicians typically use. The safe DIY troubleshooting in the video doesn’t rely on live voltage checks, while service technicians often use live voltage checks to quickly diagnose the water heater problem.

While many DIY’ers have been able to find the cause of water heater failures using the troubleshooting advice shown in the video, some failures such as a bad circuit breaker can only be found using live voltage checks which should only be conducted by a trained service technician.

Consult with an Experienced Water Heater Repair Expert

If you need your water heater repaired, schedule service with one of our water heater repair experts today. Sears Technicians have the training, tools and expertise to quickly find the cause of a water heater failure. Rely on our technicians to diagnose and repair your water heater or any other appliance in your home that quits working.

While the technician is in your home, take advantage of appliance Cleaning & Maintenance offers that the tech discusses with you. Keeping your appliances well-maintained will help them work more efficiently and last longer. Regular professional maintenance will also help prevent costly breakdowns of the appliances you depend on every day.

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