6 ADT Carbon Monoxide Detector Known Problems (Solved)

TechGenuinely is supported by readers. When you buy with our links, we may earn a commission.

The ADT carbon monoxide detector is a great tool for identifying dangerous gases, especially in homes with poor airflow. 

Having a working detector is crucial because carbon monoxide can quickly become very fatally harmful if something goes wrong. 

If your ADT CO detector isn’t working right, or if you’re thinking about getting one and want to avoid any potential problems with the device, this article is just for you.

ADT detector issue

ADT Carbon Monoxide Detector Tamper

Your ADT Carbon Monoxide Detector includes a Tamper Detection feature. This feature is designed to notify you by triggering an alarm if any attempt to tamper with the smoke detector is detected. 

Sometimes, however, the tamper alarm may go off without any apparent sign of being tampered with

This false tamper alarm may happen for several reasons. Below are the major ones to consider:

  • Your detector’s cover is coming loose.
  • A part of your detector has been damaged.
  • Your detector’s cable is damaged. 

Another thing to note about the tamper alarm is that your ADT Carbon Monoxide Detector doesn’t have to be armed to trigger it. 

Suppose the detector observes any sign of being tampered with. In that case, the tamper alarm will be triggered automatically regardless of the current mode of your alarm system. 

While a false tamper alarm can cause a nuisance, fixing it is relatively straightforward. 

You’d want to start by identifying the fault. 

Usually, it’s one of the four things below:

Battery Cover:

Check the battery cover of your ADT Carbon Monoxide (CO) Detector. Ensure you don’t just place it but properly seat it and lock it into position. There’s usually a specific way to align and lock it; look for any signs or arrows indicating how it fits.

Back Cover:

After securing the battery cover, check the detector’s back cover. This part attaches the detector to the wall or ceiling. 

Remove it and then re-apply it, making sure it clicks or locks into place securely. This step is crucial because if the back cover is loose, it might trigger the tamper alert.

Base Location:

Suppose your Carbon Monoxide Detector isn’t mounted adequately on your detector’s base unit. In that case, you might also have issues with false tamper alarms. 

So, when dealing with a tamper alarm, you should also ensure your device is mounted correctly. 

Also, ensure the Base unit of your ADT system is centrally located in your home. 

While this doesn’t directly relate to the tampering issue, it’s essential for the overall system health. 

The Base should be free from any objects on top or close to it that could disrupt its signal to the detectors and other sensors.


Your ADT Carbon Monoxide Detector may be wired. Any damage to the detector’s wiring would also trigger a tamper alarm. So, if there are no issues with either the battery cover, back cover, or the base unit, then check the wiring.

Unfortunately, fixing issues with your detector’s wiring won’t be as easy as fixing the other issues listed above. If you find any issues with your wiring, we recommend contacting an expert to help resolve the problem.

Fixing the four issues mentioned above would typically eliminate your tamper alarm. 

Suppose your ADT Carbon Monoxide Detector still shows a tamper alert even after fixing the abovementioned issues. In that case, it’s likely there’s a more complex issue at hand. 

It’s also possible that your detector itself is malfunctioning. 

In this case, consider getting support. For personalized help, use the “Chat with an Agent” feature. 

You can usually find this option in the lower right corner of the ADT support page. An ADT agent can guide you through more detailed troubleshooting steps or arrange for a professional technician visit if necessary.

Remember, the aim is to ensure that the battery and back covers are adequately secured and that the device’s location supports optimal signal transmission. 

ADT Carbon Monoxide Detector Flashing Green Light

If your ADT Carbon Monoxide Detector is flashing a green light, it shows that everything is standard with the device. 

The flashing green light, which happens every 10 seconds, indicates that the detector is functioning correctly and monitoring the air for carbon monoxide without detecting any dangerous levels. 

ADT Carbon Monoxide Detector Flashing Yellow Light

Suppose the amber light on your ADT Carbon Monoxide Detector blinks every 45 seconds. In that case, it means the batteries are low and need replacing. 

When you see the amber light, change the batteries promptly. Make sure to use the correct replacement batteries and follow the battery replacement instructions. 

If you recently set up the detector, make sure you removed the battery tab only when instructed by your ADT Virtual Agent during the initial setup. The batteries may not activate if the tab is still in place.

Remember to regularly test your Carbon Monoxide Detector to ensure it’s working properly, and keep spare batteries on hand to replace them right away when the low battery warning occurs. 

Here are some other LED indicators you may need to know about.

  • Green Light: Indicates regular operation, blinking every 10 seconds. (As previously explained in Section 2 of this article.)
  • Red Light and Four Beeps: Signals an alarm condition, prompting immediate evacuation.

ADT Carbon Monoxide Detector Chirping

If your ADT Carbon Monoxide Detector is chirping or beeping, you must first understand the type of sound it’s making and what it means. 

Here are a few beeping patterns you may need to take note of:

Continuous High-Pitched Beeping

Emergency Situation: If the alarm continuously beeps with a high-pitched sound, it indicates a carbon monoxide leak. 

If so, contact emergency services immediately. Call 911 and get outside for fresh air if anyone has flu-like symptoms.

30-Second Chirps

End-of-Life Warning: If your detector makes chirping sounds every 30 seconds, it’s likely reaching the end of its six—to seven-year lifespan. Replacing the battery will not stop this beeping. For wall socket detectors, check for a loose battery.

Random Beeps

Low Battery Signal: Check the battery if the detector chirps randomly. Low batteries can cause a chirp every minute. Frequent beeping may indicate the presence of carbon monoxide.

Regular Beeps (Every 5 Minutes)

Malfunctioning Detector: Three consecutive beeps every five minutes indicate a malfunction. Consider replacing the detector, mainly if it’s a newer model that communicates with you through messages or changes in light colors.

How to Turn off ADT Carbon Monoxide Alarm?

Here’s how to turn off your ADT carbon monoxide alarm depending on the kind of beeping you’re experiencing:

Continuous Alarm 

If the alarm is continuous and shrill, it signifies an emergency. Get outside for fresh air and contact emergency services before re-entering.

Other Beeps

  • Replace or Check the Battery: Reinstall or replace the battery and reset the device.
  • Check LED Lights: Understand LED status. Some detectors have “error” messages. Intelligent sensors can provide further information through the app.
  • Find False Alarms: Ensure the detector isn’t too close to fuel-burning appliances to prevent false alarms.
  • Reset the Detector: Locate the “silence” or “reset” button, hold it for 10 seconds, release it, and observe the LED lights or listen for a beep. Smart detectors can be reset through their apps.

Remember that promptly addressing the beeping ensures that your ADT Carbon Monoxide Detector operates effectively, offering crucial and timely protection against the dangers of carbon monoxide.

How to Reset ADT Carbon Monoxide Detector?

To reset your ADT Carbon Monoxide Detector to factory default, you can simply follow these easy steps:

  1. Activate Test mode for your system.
  2. Carefully turn the mounted device counterclockwise to unlock and detach it from the mounting plate.
  3. Open the battery door located at the back of the detector.
  4. Take out the CR123A battery from the sensor.
  5. Press and hold the blue tamper button on the detector.
  6. While holding the blue button, reinsert the battery.
  7. Keep the button pressed for 20 seconds (not exceeding 30 seconds to avoid reset failure).
  8. Release the blue button, put the sensor’s battery cover back on, and slide it into the locked position.
  9. Deactivate Test mode for your system.

Note: If the detector is reset while linked to your account, it will be unlinked and must be set up as a new device using the ADT+ app. You can refer to the instructions for removing and adding devices here.


While the ADT carbon monoxide detector is a reliable device, some of the issues discussed in this article can still occur. If faced with any of them, simply refer to the above guide to fix the problem.

But remember, if you’re faced with any issues beyond your ability to resolve, don’t hesitate to get help from customer service. They are often in the best position to offer proper guidance.

About Author

I'm Maroun, the seasoned technology writer crafting compelling tutorials and posts since 2013. With over a decade of versatile experience spanning the IT, Security, and High-tech industries, my main qualities are adaptability and perfectionism. Join me in this journey, where every word is a masterpiece!
Read more about Maroun

Need Help: We hope you were able to solve your problem and find answers to your questions. Not really? Contact us.