ADT Door Sensor Not Working? Complete Fix Guide

Is your ADT door sensor not working suddenly? Well, you might be looking at a problem with the magnet.

However, more often, wireless door sensors are not working due to worn-out batteries and issues with the sensor’s covers.

Those types of issues can be easily solved, so let’s learn more about the solution.

To fix an ADT door sensor, first, replace the battery and ensure that the units are embedded correctly. Attach the sensor’s magnet appropriately, secure the sensor’s cover and reprogram the door sensors. Lastly, if nothing helps, reset the sensor.

Why Is ADT Wireless Door Sensor Not Working?

There could be multiple problems at once causing your door sensor to stop working.

Chances are that the batteries got worn out or the door sensor needs resetting to continue its duty.

Here are the causes for the problem you’re experiencing with the ADT door sensor:

1. Worn-Out Batteries

If the batteries of your door sensor are faulty, you have to replace them in order for the issue to be solved.

2. The Sensor is Unprogrammed

The sensor may be disconnected from the control panel and you will have to pair it back.

3. Magnet not Attached Properly

If the sensor doesn’t make contact with the magnet, it won’t work.

4. Software Blunder with Sensor

An issue with the sensor’ software will cause the device to stop working. Such an issue can be a faulty chime sound.

5. The Sensor is Damaged

A problematic sensor in general, hence, a hardware problem, which is unlikely, maybe the fault you’re looking at in your situation.

We will exclude the hardware failure as a possibility and attempt to solve all other occasions in which the ADT door sensor would not be working.

How To Fix An ADT Sensor Not Working?

The solution that is coming up in our fix guide is designed to troubleshoot your ADT door sensor in consecutive steps.

Make sure that you follow them in the correct order and test your sensor after each step to find out if the issue is fixed.

Here’s how to troubleshoot your ADT wireless door sensor in easy solutions:

Solution #1 Replace Door Sensor/Use Correct Battery

One of the major problems that could have occurred with your ADT door sensors is an inappropriate battery or worn-out battery.

Regardless of the battery situation, you will either have to replace the entire battery or have the units inserted correctly.

Here’s how to replace your ADT door sensor’s battery in easy steps:

1. Grab a flathead screwdriver and push the tab, located on the end of the contact.
2. The battery inside is a CR123A 3 volt battery, so make sure to acquire one of the same type.
3. Eject the old battery inside and insert the brand new battery as you mind the poles.
4. Close the compartment and test.

Note: If the display of the sensor flickers, it means that the device is running and the battery has been attached securely. 

If it doesn’t, however, re-insert the batteries and check the electric poles.

Solution #2 Secure The Sensor’s Cover

Not having the cover latch of your sensor secured might prevent the device from working.

When having the cover pushed all the way, it will apply pressure to the batteries as well, causing them to fit in the compartment tightly.

The sensor’s cover is located on the rear front of the device. You should hear a click when having the cover pushed all the way in.

This click sound is how you know that the cover has been securely attached to the sensor and shouldn’t cause problems.

Note: The cover is only lifted when having the batteries replaced. 

It’s extremely important to hear the click, especially after replacing or interacting with the batteries in solution #1.

Solution #3 Attach Sensor’s Magnet Properly

Chances are that the sensor’s magnet hasn’t been attached properly.

If you haven’t installed it the way you have to, the sensor and the magnet won’t make contact, therefore the sensor will not work when somebody opens your door.

Here’s how to correct the magnet’s position in your ADT setup:

1. Unscrew the screws holding the magnet on your door.
2. Correct the magnet’s position, so it matches the sensor’s position.
3. Screw the magnet tightly, but make sure not to overdo it.
4. Close the door and test.

Note: For the sensor to work well, the position of the magnet and the sensor must be equalized correspondingly.

Solution #4 Update Chime Code

There are plenty of reports that updating the chime code of your door sensor may fix the problem.

That’s to say because if you have left the sensor outdated, the old file of the chime might have gotten corrupted and the sensor won’t work well.

Here’s how to update the chime code of your ADT door sensor:

1. Go over to your door sensor.
2. Press the star key once and then the number 5.
3. Enter the master-code number (6 digits).
4. Select an alternative chime code, identified with the buttons from 01 to 32.

Note: To determine if the issue has been solved, trigger the sensor only after updating the chime code and test your setup.

Solution #5 Reset The Door Sensor

If nothing worked so far, you should reset the door sensor that’s giving you the problem.

The reset will help with software issues that are preventing the device from chime whenever the door is opened.

Here’s how to perform a factory reset on your door sensor in easy steps:

1. Go over to your ADT door sensor.
2. Locate the pairing button on the device’s back (small button labeled with a “P”).
3. Press the pairing button down and hold it for 10 seconds.
4. Once the 10 seconds have passed, let go of the pairing button on your ADT door sensor.

Note: The reset may cause the sensor to disconnect from the control panel.

If that happens, you will have to pair the device back to the control panel with a press on the pairing button.

ADT Door Sensor Still Not Working…

If you’re still getting issues with your ADT door sensor, then the problem you’re facing might be a little more complex.

It might even require you to do some purchases, in case some of the components are dead.

Our recommendation would be to consider contacting a technician to see if they can fix the problem for you, before making any purchases on your own.

Tip: Check if your warranty is intact.

Thus, to fix the ADT wireless or wired door sensor, replace the batteries and identify problems with the wires. Choose an alternative chime sound for the sensor, reposition the magnet, update the chime code and only then perform a factory reset.

Read Next: Why Is Genie Garage Door Sensor One Red One Green?

Bottom Line:

Now that you know how to fix the ADT door sensor not working, the performance depends on you.

Keep in mind that contacting a technician to solve the problem for you is always a smart approach, especially before making any purchases.

For more similar guides and posts, make sure to visit our online technical blog to discover the solutions you need.