An "Err" message may appear on your carbon monoxide alarm’s digital display for several different reasons.

Responding to an Alarm Malfunction

In the rare event that your alarm malfunctions, it will alert you with a short Chirp, and the Red LED will flash once every 30 seconds.


If your alarm is malfunctioning, perform the following steps:

  1. Push and hold the Test/Reset button for 5 seconds, and then release the button. If the reset is successful, the display will reset to zero. If it's an actual malfunction, the unit will go back to Err within 5 minutes.

  2. After you reset the alarm, if it is malfunctioning, you need to press and hold down the Peak Level NOTE: The Err message will change to a Err code. It will start with an E and have two numbers after it.

  3. Once the error code is displayed, call us on our hotline at 1-800-880-6788, provide an agent with the code, and they will assist you further. Please make sure that you have your alarm's model number, date of manufacture, and assembly number (if visible), so you will not have to call back.

Responding to a Power Surge

A power surge may be the cause of an Err message. If you think a power surge may have been the cause, push and hold the Test/Reset button for 5 seconds, and then release the button.


NOTE: If it was just a surge that created the Err message, the reset will change the display to zero and stay there.

Responding to an End-of-Life Warning

An Err message may be due to an End-of-Life warning. Seven to ten years after initial power-up, this unit will Chirp every 30 seconds to indicate that it is time to replace the alarm.


WARNING: The unit will not detect carbon monoxide in this condition.


If your alarm has reached its End-of-Life warning, replace the alarm immediately. For more information about your specific alarm, refer to your user’s manual.