ADT sensors are reset by removing and re-adding them. In the ADT+ app open the menu, choose Devices, select the sensor and tap Remove Device, then Yes; once removed it no longer monitors the area. Add it again with Devices, plus, ADT Devices, Sensors and Detectors and follow the prompts. Removal makes sense if the device was lost or stolen, you moved and left it behind,
The checks in more detail
or it was reset while already paired to an ADT+ account, in which case it must be removed and set up as new. ADT's offline article says a sensor that will not reconnect may need removing and adding back, and its low battery article says a message that does not clear more than 24 hours after a battery change means you should delete and re-add the sensor. Before removing, note the sensor's name and location.
After re-adding, test it with the system disarmed and in Test Mode. For Z-Wave accessories such as a Live Light, use Smart Home Device and inclusion or exclusion mode. Do not remove several sensors at once, so you can find which one has the fault. Contact ADT chat if a sensor will not re-add. Photograph the sensor labels before removing devices so you can identify them later. After re-adding, give the sensor a moment before testing.
Avoid removing sensors when the house is empty. A sensor that was reset while still paired must be removed from the account first, so if it will not add, check the account before checking the sensor. Keep the mounting hardware in place when removing a sensor so it goes back to the same spot, and record its name so that rules that referred to it can be rebuilt.
Differential
Likely causes of “ADT sensors and detectors will not reset or needs to be reset safely”, and how to tell them apart
- 1
A sensor that will not reconnect
What separates it The sensor is shown offline in the app and will not come back after a battery change or a move
How to confirm Remove the sensor from the app and add it again so that it pairs afresh with the Base
- 2
A lost or stolen sensor
What separates it A lost or stolen sensor still appears on the account and could still be used with your Base
How to confirm Remove the sensor from the Devices list so that it can no longer be used with your system
- 3
A reset while paired
What separates it A sensor that was reset by hand still shows as paired and refuses to be added again
How to confirm Remove the old entry, then add the sensor again as a new device beside the Base
- 4
A low battery that persists
What separates it A low battery message stays after a new battery has been fitted, and the sensor keeps reporting low
How to confirm Delete the sensor and add it again after waiting so the message can clear properly
- 5
A moved household
What separates it Old sensors from a previous home are still on the account after a move to a new address
How to confirm Remove the old sensors and set them up again in the new place beside the Base
Before you touch a setting
Record this first — changing settings destroys the evidence
- The sensor's name and where it is located
- The state of the sensor's battery and its LED
- Whether the sensor was reset by hand and how
- The step where the removal failed, if it did
Try in this order
0 of 7 completedNote the sensor name
ReversibleNote the sensor name and its location, so that you can give it the same name and place when you add it again.
Open Devices
ReversibleOpen Devices in the app, which lists every sensor paired to the Base and lets you select the one you want to remove.
Remove the sensor
ReversibleRemove the sensor and confirm, which stops it monitoring the area and takes it off the Base until you add it again.
Add it again
ReversibleAdd it again from Sensors and Detectors in the app, choosing the correct sensor type from the list.
Pair beside the Base
ReversiblePair the sensor beside the Base with a fresh battery, so the pairing succeeds first time and the signal is strong.
Test in Test Mode
ReversibleTest in Test Mode after re-adding, to check the sensor reports and that the alert reaches the app.
Contact ADT
ReversibleContact ADT if the sensor will not remove or add after these steps, and have its type and location to hand.
Model-specific
What is true of this model and not of its siblings
- Reset
- Handled as remove and add.
- Z-Wave
- Uses inclusion and exclusion.
- Other models this page answers
- These steps also fit the Live Light.
Stop boundary
When this stops being a self-service repair
- !If a sensor will not re-add, contact ADT through chat
- !If the sensor was second-hand, ask ADT to remove it from the previous owner's account
- !If several sensors fail at once, check the Base before you reset any of them
Evidence ledger
Sources behind this answer
Removing and adding devices.
Offline meaning and fixes per device.
Battery types and lives.
Motion sensor setup and use.
The company and its products.
Exact questions
Common questions
How do I reset a sensor?+
To reset a sensor, remove it in the ADT+ app and then add it back, since ADT treats remove and re-add as the reset for its sensors.
Does removal stop protection?+
Yes, once a sensor is removed it no longer monitors the area, so the location is unprotected until you add it back.
When should I remove?+
Remove a sensor when it is lost, when you are moving it, or when you want to reset it and pair it afresh.
What if a battery message persists?+
If a low battery message persists after fitting a new battery, delete the sensor and add it again to clear the old state.
How do I test after?+
Test in Test Mode after adding it back, and check that the app reports the sensor and that an alert reaches your phone.
Should I remove many at once?+
No, do not remove many at once, because you may then lose track of which ones are protecting which rooms.
Where should the Base be for sensors?+
The Base should sit in a central position and be clear of objects, so that the radio link reaches every sensor.
How do I add a motion sensor?+
In the ADT+ app open Devices, tap plus, choose ADT Devices, then Sensors and Detectors, and follow the steps for the motion sensor.
Is the motion sensor pet-friendly?+
Yes, the ADT motion sensor is pet-friendly, so ordinary pet movement is not meant to trigger it.