Water heater not working? Fix your gas or electric unit with these simple steps

If you’ve ever asked, “Why is my hot water heater not working?” you’ve come to the right place! We’ll explore common reasons for gas and electric water heaters failing and provide easy-to-follow troubleshooting steps, so you can get your unit running again.

If you need any replacement parts for your appliances, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

Important: The information provided in this article may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

Common reasons your water heater is not working

Several issues can cause a gas or electric water heater to stop working. These include:

• Faulty thermostat
• Broken heating elements (for electric water heaters)
• Pilot light or gas control issues (for gas water heaters)
• Tripped circuit breaker
• Sediment buildup in the tank

Troubleshooting steps  

Check the power supply (Electric heaters)

Check the circuit breaker

1. Head to your main electrical panel and check the breaker for the water heater. If it’s tripped, reset it by flipping it off and then back on.
2. If it trips again immediately, there might be a short circuit, and you’ll need to check wiring or replace parts.

Reset the high-temperature cutoff switch

1. Turn off the circuit breaker for the water heater.
2. Remove the access panel on the heater and press the red reset button located near the thermostat. If it clicks, it was tripped, and resetting should restore power.
3. Replace the access panel, turn the breaker back on, and wait about 30 minutes. 

If the water doesn’t heat up, continue to the next steps.

Use a multimeter to test the heating elements

1. After turning off the power, use a multimeter to check the heating elements. Set the multimeter to the lowest resistance setting (Ohms).
2. Place one probe on each terminal of the heating element. If the multimeter shows no reading or infinity, the element is faulty and needs to be replaced.

Check the gas supply and pilot light (Gas heaters)

Verify the gas supply 

Ensure the gas valve to your water heater is fully open. If it was closed, open it and wait for a few minutes for the gas to flow into the system.

Relight the pilot light (if applicable) 

1. Check through the viewing window at the bottom of your unit to see if the pilot light is on.
2. If the pilot light is out, follow the instructions on the heater to relight it. Usually, this involves turning the control knob to “Pilot” and holding down the ignition button while lighting the pilot with a long lighter.
3. If the pilot light won’t stay lit, it could be a faulty thermocouple. The thermocouple senses when the pilot light is on and shuts off the gas if the pilot goes out. Replace it if necessary.

Test the thermocouple  

1. Use your multimeter to test the thermocouple if the pilot light won’t stay lit.
2. Set the multimeter to millivolts and attach one probe to the thermocouple end and the other to the gas valve connection. 
3. A working thermocouple should read 20-30 millivolts when heated by the pilot. If the reading is lower, replace the thermocouple.

Adjust or replace the thermostat (Both gas and electric heaters)

Check the temperature setting

1. Locate the thermostat (you may need to remove an access panel for electric heaters).
2. Make sure the temperature is set between 120°F and 140°F. If it’s set too low, raise it and wait to see if the water heats properly.

Test the thermostat (Electric heaters)

1. After turning off the power, use a multimeter to test the thermostat for continuity.
2. Set your multimeter to continuity mode and place the probes on the thermostat terminals. If there’s no continuity, the thermostat needs to be replaced.

Flush the water heater (Both gas and electric heaters)

Drain the water heater to remove sediment

1. Sediment build-up can cause heating issues. Turn off the power and gas and close the cold water inlet valve.
2. Attach a hose to the drain valve at the bottom of the tank and place the other end outside or into a drain.
3. Open a hot water faucet nearby to let air into the system, then open the drain valve to empty the tank.
4. Once the tank is drained, close the valve, remove the hose, and refill the tank by opening the water supply. Turn the power or gas back on after the tank is full.

Check for leaks (Both gas and electric heaters)

Inspect the tank and connections for leaks

1. Check around the tank, pipes, and valves for any signs of leaks.
2. If you find leaks at the pressure relief valve or drain valve, you may need to tighten connections or replace those parts.

People also ask

Why is my water heater not working?

There are several reasons your water heater is not working:

• For electric water heaters, it could be due to a tripped circuit breaker, a blown fuse, or a faulty heating element.
• For gas water heaters, common issues include a lack of gas supply, an extinguished pilot light, or a malfunctioning thermocouple. In both cases, sediment buildup or a faulty thermostat may also prevent the heater from working properly.

How do I reset my water heater?

To reset an electric water heater, locate the reset button on the thermostat. This button is often red and located behind an access panel. Press the button to reset the system.
For gas water heaters, resetting involves turning the gas valve to the “off” position for a few minutes, then back to “pilot” to reignite the pilot light. Always refer to the manufacturer’s manual for specific reset instructions.

What do you do when your water heater doesn’t work?

When your water heater doesn’t work, follow these troubleshooting steps:

• Check the power or gas supply.
• Inspect the thermostat for faults.
• Flush the tank to remove any sediment buildup.
• Test the heating elements or burner.
• If the issue persists, consider replacing faulty parts like the thermostat or thermocouple.

How do I know if my water heater element is bad?

To check if the water heater element is bad:

• Turn off the power to your electric water heater.
• Use a multimeter to test the heating element for continuity. If the reading is zero or infinity, the element is faulty and will need replacement.
• Signs of a bad element include water taking longer to heat, or no hot water at all.

What should I do if my gas water heater is not heating water?

If your gas water heater is not heating water, try these steps:

• Ensure the gas supply is on and that the pilot light is lit. If the pilot is out, relight it according to your manufacturer’s instructions.
• If the pilot won’t stay lit, the thermocouple may be faulty and need replacement.
• Check for sediment buildup, which can insulate the burner and reduce heating efficiency.
• If these steps don’t resolve the issue, call a professional technician for further diagnosis.

Additional information

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