How do I disconnect the smoke detector from my Adt system? It has been chirping since I canceled the service.

Change the battery, the chirping is an indication of a weak battery.

Hello

@ Talaniman you are only part right and I'll explain why

Ok I am guessing we are dealing with a complete alarm system ( A few PIR sensors , pet sensors , door or window sensors etc , Key pad , Siren whether internal or external or both , Panel ( See picture below for what I mean by panel ) , optional smoke alarm .

If this is what we have , then the reason I said you are partly right talaniman is that the smoke alarm is hard wired ( See picture below ) to the panel ports via 4 wires generally , unless wireless ( AC red / black ) and Green or Yellow for one into comms and one into sensor port all on panel.

Note = This is how they are done in my country wire colour wise, though it should be still 4 wires generally ( some only have 3 wires , less functions ).

Now it could be the battery connected to the panel if you have turned the main power off to the system, and it's been programmed to chirp via the smoke alarm.

It could also be the programming if the panel is still trying to communicate with your monitor though you have had the service canceled, and it's chirping to tell you there a coms issue , or a possible test signal.

If it is a wireless Smoke Alarm to panel , then yes it can also chirp if the battery in it is low.

Best advice , call a tech in to take a look and maybe reprogram some parts of the system, heck if you really want to have your own phone number or more added to the system so you are the response / monitor of the alarm if it goes off.

Hope this helps.