Why isn't my water heater heating my water?

For electric water heaters, check both house circuit breakers for the water heater. Reset the circuit breakers by shutting them off and then flipping them back on. A gas water heater will have a single circuit breaker. Reset that circuit breaker the same way-shut it off and flip it back on.

If the electric water heater doesn't begin to heat after resetting the circuit breakers, shut the breakers off and press the reset button for the high-temperature limit switch on the upper thermostat of the water heater. If the water heater works for a while and then trips the high-temperature limit switch again, you'll likely need to replace a failed thermostat that's causing the element to heat constantly. If an electric water heater element doesn't heat when activated, replace the heating element. Replace the thermostat if it doesn't activate the heating element. Our no-hot-water troubleshooting video can help you figure out which part to replace in an electric water heater that's not heating.

For gas water heaters, make sure you have an adequate gas supply provided to the water heater and check the gas supply shut-off valve to make sure it's fully open. If your gas water heater uses a pilot light for ignition, relight the pilot if necessary. Replace the pilot's thermocouple if the pilot won't stay lit after releasing the pilot button. Replace the thermostat if it doesn't turn on the burner to heat the water. Replace the burner assembly if it's at fault. The gas water heater has ventilation interlock switches. Have a service technician examine the gas water heater if basic troubleshooting doesn't resolve the water heating failure.

Sears Home Services repairs all types of water heaters. For example, if you find your AO Smith water heater not heating, we’ll fix the problem with original manufacturer replacement parts.