To completely disconnect an ADT alarm system, you must first cancel your monitoring contract by calling ADT at 800-238-2727 to avoid early termination fees. Next, perform a physical power down: unplug the system's transformer from the wall outlet, and open the main panel box to disconnect the black backup battery leads.
If you purchased your ADT system online, you can cancel your monitoring online: If you use MyADT, log into your account on myadt.com, click Account > Manage Subscriptions, and fill out the cancellation form.
You can unplug your ADT system, but simply pulling the plug won't instantly shut it off. Because of built-in security features, the system has a backup battery that will keep running, and it will likely trigger beeping alerts.
No. ADT cancellation must be done by phone. Call 800-238-2727 during business hours. Online cancellation is not available.
Open the front of the alarm panel, it may be held in place by a couple of screws. Once inside locate the battery, the battery will have two connections, a red and a black, remove both of these connections.
Disabling a hardwired alarm system requires cutting off both its primary AC power and its backup battery to completely shut it down.
Whether your house alarm will work without a battery depends on the type of alarm and the power situation:
Canceling ADT can be a frustrating process, known for long hold times and aggressive retention tactics. To cancel, you must call their customer retention department at 1-800-238-2727.
To quickly deactivate a home alarm system, simply enter your 4-to-6-digit user code on the main keypad and press the "Disarm" or "Off" button. If you do not know the code or the system is malfunctioning, you must perform a full power-down by unplugging the main AC transformer from the wall outlet and disconnecting the backup battery inside the metal control panel.
However, if your alarms are wired into your home and you're not skilled or comfortable with electrical work, it's time to hire an electrician. A professional electrician can ensure the system is fully deactivated and that all components are removed safely.
How to arm or disarm your ADT system
To turn off a house alarm without a code, you must completely cut the system's power. Locate your main control panel (usually in a utility closet, basement, or garage), open the metal box, and disconnect the backup battery. Next, unplug the transformer from the wall or flip the dedicated circuit breaker.
You can unplug your ADT system, but simply pulling the plug won't instantly shut it off. Because of built-in security features, the system has a backup battery that will keep running, and it will likely trigger beeping alerts.
ADT generally does not remove equipment after you cancel your service. In most cases, they will leave the hardware (keypads, sensors, etc.) at your property.
The ADT Quick Exit feature lets you briefly leave the house or let a pet out while your system is in "Arm Stay" mode, without triggering the alarm or fully disarming the system. It gives you a temporary window—usually 60 to 120 seconds—to open a designated exit door and close it behind you.
If so, the device will run on its backup battery for up to 24 hours, and you will get a low battery alert as it is depleted. If AC power is not restored before the battery dies, the device will power down. Once the power comes back on, the device will turn on, and the backup battery will begin to charge.
Yes. Low voltage or a disconnected battery can reset or confuse your vehicle's security system, causing it to block ignition. After replacing or jump-starting a battery, the system may need to be reinitialized properly.
Even after the battery has been removed, the detector maintains a residual charge that will keep the chirp going for some time. To get the device to stop chirping once the battery has been removed, you must drain this residual charge by holding the test button for 15 seconds.
Contact the old home security company
Most systems will alert the service when wires are cut or disconnected. If you neglect the crucial step of notifying the company that you are disconnecting the system, don't be surprised when it signals an emergency.
To turn off a house alarm, the fastest and most common way is to enter your 4- to 6-digit security code on the main keypad and press the "Disarm" or "Off" button. If you don't know the code, you will need to cut the system's power.
Disconnecting a hardwired smoke detector instantly disables that unit's fire detection. Because they are often interconnected, unplugging one can break the communication loop, meaning other detectors in your home may fail to sound an alarm during an emergency. It can also create an electrical shock hazard if the live wiring harness is left exposed.
To completely remove an ADT security system, first cancel your monitoring agreement to avoid early termination fees. Once your contract is clear, cut off the system's power completely, unscrew the hardware, pull the wires out from the walls, and patch any holes with drywall spackle.
Burglar alarm removal prices in the UK typically range from £80 to £500. Labour rates can be between £30 to £60 per hour, totalling £60 to £300 depending on the project size. Material costs, including tools and equipment, disposal fees, and repairs, can add another £15 to £100.
Most home monitoring services will automatically dispatch local police if your system loses power. Disconnecting wiring or causing the old system to lose power may set off a false alarm, resulting in an unnecessary emergency response that could land you with a fine.