American  Water Heater  (Electric) Error Codes

These error code explanations can help you diagnose a problem with your American electric water heater.  For repair how-to help, visit the PartsDirect repair help section, which includes repair help for water heaters, major appliances, lawn and garden equipment, garage door openers, vacuum cleaners and more. You can also search for owner’s manuals and find water heater replacement parts.

Check out our water heater error code charts for information on a different brand of water heater.

Error Code Condition Check/Repair Shop Parts
Green LED 1 Flash Power applied before tank is filled with water Open the nearest hot water faucet, and fill the water heater until a steady stream of water flows out of the faucet. Once the water heater is completely filled, then shut off the faucet. Reset the heater. Turn the power off, then back on. Press the reset button on the control box. Wait 10 minutes.
2 Flashes High water temperature and shut down Turn the power off to the water heater and remove the control box cover. Using a multi-meter, check the ohm resistance of the upper and lower heating elements between the blue and yellow wire connections (upper element) and the orange and blue wire connections (lower element). The ohm resistance should measure between 5-25 ohms. Replace the element if it does not measure 5-25 ohms. If the heating elements are okay, remove the thermistor plug from the control board. Using a multi-meter, measure the resistance between the red wires in the thermistor plug, then measure the resistance between the two black wires in the plug. Open a hot water faucet and measure the water temperature. If the water temperature is between 80 and 100 degrees Fahrenheit, the thermistor should measure between 50k-20k ohms; 100-120 degrees should measure 40k-15k ohms; 120-150 degrees should measure 30k-5k ohms. If the thermistors and heating elements are within ohm specification, replace the control board
See the repair guide to fix it yourself
Heating element, Thermistor, Control board
3 Flashes Thermistors not operating correctly Turn off power to the heater, and remove the control box cover. Check that the thermistor plug fits tightly on the control board. Remove the thermistor plug from the control board. Using a multi-meter, measure the resistance between the red wires in the thermistor plug, then measure the resistance between the two black wires in the plug. Open a hot water faucet and measure the water temperature. If the water temperature is between 80 and 100 degrees Fahrenheit, the thermistor should measure between 50k-20k ohms; 100-120 degrees should measure 40k-15k ohms; 120-150 degrees should measure 30k-5k ohms. If the thermistors and thermistor wires are okay, replace the control board
Heating element, Thermistor, Control board
4 Flashes Upper heating element failure Turn off power to the water heater and remove the control box cover. Inspect the yellow and blue wires connected to the relays for damage. Using a multi-meter, measure the resistance between the yellow and blue wires connected to the relays. The ohm resistance should be 5-25 ohms if the upper heating element is okay. If the upper heating element is defective, replace it. If the upper element and wiring are okay, replace the control board.
See the repair guide to fix it yourself
Thermistor, Control board
5 Flashes Lower heating element failure Turn off power to the water heater and remove the control box cover. Inspect the orange and blue wires connected to the control for damage. Using a multi-meter, measure the resistance between the orange and blue wires. The ohm resistance should be 5-25 ohms if the lower heating element is okay. If the lower heating element is defective, replace it. If the lower element and wiring is okay, replace the control board.
See the repair guide to fix it yourself
Lower heating element, Control board
6 Flashes Lock-out condition The water heater stops working due to a malfunction in the control board. Reset the unit by turning off power and waiting 10 minutes. If the green light is still flashing 6 times after resetting the control, replace the control board.
Control board