How to Turn Off ADT Alarm System Without a Code

Person pressing a button on their alarm keypad system.Person pressing a button on their alarm keypad system.

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A typical ADT security alarm system is between 100 and 115 decibels — which is pretty loud. And to make matters worse, now you’re standing next to your blaring alarm and can’t turn it off because you don’t remember the code. Now what?

  1. Locate and remove the transformer plug from the outlet.
  2. Disassemble the security panel.
  3. Remove the backup battery.

There are other novel ways to turn off an ADT alarm that don’t involve acute panic and a baseball bat. While there’s no need to panic, there is an urgency to shut off the alarm. Neighbors may call the police, it’ll drive dogs crazy, and it may incur potential fines.

How to Turn Off Your ADT Alarm Without a Code

Maybe your elderly mother installed a security system without telling you, or maybe the friends you’re house-sitting for gave you the wrong code. Either way, it is possible to turn off an ADT alarm without a code.

There are many different ADT security systems, though all essentially follow the same routine. 

  1. Locate and unplug the alarm’s transformer. This is a large, square plug screwed into a power outlet.
  2. Find and open the alarm’s security panel box. This is separate from the keypad. 
  3. Inside the panel box, you’ll find a battery attached by two leads. Disconnect these leads and remove the battery.

Once you do this, the alarm should shut off.

Note: If you can’t find or disconnect the transformer, the easiest thing to do is cut the power from the circuit breaker. Some batteries will be located in the security panel itself, adjacent to the keypad, or directly behind it. 

Removing an ADT Command/Pulse Battery

The battery for the ADT Command and Control Panel is located behind the touch screen. Usually, you would use the touch screen to select “Tools,” then enter your user access code to shut the system down. 

But to remove the battery without a security code, you need to: 

  1. Remove the screw at the bottom center of the panel with a Phillips-head screwdriver.
  2. Slide the touch screen up and off the wall panel to access the back.
  3. Remove the final screw securing the plastic clasp to the battery, then remove the clasp.
  4. Pull back the quick-connect and remove the battery.

Using the ADT Key Fob to Disable the Alarm

Maybe the homeowner didn’t give you the code, but they did give you a key fob (or leave one lying around). 

If the code isn’t working, you can use this key fob to turn off the ADT security system. Hold the key fob in your hand and press “Disarm” on the ADT keypad.

Note: Some key fobs require a two-second button press. If the disarm button doesn’t work on its own, hold it down for two seconds. 

How to Avoid Future ADT Alarm Triggers

If this experience traumatized you enough, you’ll want to take a few steps to avoid accidental triggers in the future. 

If you’re trying to access someone else’s alarm, the only real step you can take is to call the homeowners and let them know the code isn’t working. If you are the homeowner, contact ADT and let them know about your issue. They may be able to:

  • Help you reset your code
  • Diagnose the problem
  • Send a technician to fix alarm malfunctions

Reset the ADT Alarm and User Code

If you just bought a house with an ADT alarm system you don’t know the code for, you can reset the system and replace the original user code.

This method generally works for Honeywell alarm panels. Since Honeywell/Residio manufactures most ADT panels, these step-by-step instructions should cover most security systems. 

  1. Follow the steps above for removing the battery and unplugging the transformer.
  2. Wait about a minute, then power the system back on
  3. Once it reboots, hold down the * and # keys until the system prompts you to enter the installer code (you may need to check your user manual or contact ADT to get this).
  4. Press *20 (code) *99.
  5. Enter your installer code, followed by 802.
  6. Enter a four-digit number. This will be your new master code.

Note: The ADT Command panel doesn’t have an installer code, so it can’t be changed and should simply be disconnected.

Remove the ADT Hardware

If your ADT security system is more trouble than it’s worth, you might just want to remove it altogether. 

Before you remove anything, contact ADT and let them know what you’re doing. Unplanned uninstallations could trigger a red flag, and your monitoring service may notify the police. 

It’s also a good idea to call ADT to see if they recommend removing it yourself or if they want to send a technician. If they do say it’s safe to remove on your own, follow the steps below:

  1. Cut power to the alarm system from your circuit breaker. 
  2. Remove the transformer and battery from your alarm system.
  3. Take down the control panel, sensors, and cameras. Note that door and window sensors are installed with a silicone sealant, so have something handy to soften it.
  4. Disconnect any sensor wires from the source and pull the wires through the hole.

Related Questions: ADT Alarm Systems

Can You Bypass an ADT Alarm System?

You can bypass certain elements of your ADT system, which lets it ignore signals from devices that would normally cause an alarm activation. However, you can’t bypass:

  • Smoke detectors
  • Flood detectors
  • Carbon monoxide detectors

Can You Disarm an ADT Alarm System Remotely?

You can arm or disarm the system remotely using the ADT Pulse app. Just open the app, then press the arm/disarm icon on the home screen.

Any number of users can be added to the ADT app for easy arming and disarming.

Can an ADT Alarm System Be Hacked?

While any device can technically be hacked, ADT has good security measures in place to prevent hacking horror stories.

Can You Permanently Turn Off an ADT Alarm?

Theoretically, you can turn off your ADT alarm permanently by always keeping it disarmed. If you want to deactivate it completely, call ADT and remove the AC power and battery backup.

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