[duhhs]

The house is prewired by ADT. Is there a way to tap into the existing wiring and hook up my own alarm system ? If so,Please explain the process. Thanks

[ebaines]

By "pre-wired" I assume you mean that there are cables running from all the appropriate security points (doors, windows, smoke detectors, motions detectors, heat detectors, etc) to a central location, perhaps in the basement, and also perhaps 1 or 2 control key pads in the house. If you are planning on buying and installing your own home security system it would be possible to re-use much of that wiring, but you will need to purchase and install your own control box and remote key pads. If there are sensors at the doors and windows you may be able to reuse them as well, but other sensors such as fire and motion will probably have to be replaced with units compatible with your new alarm system. So first step is: decide what alarm system you are going to buy, and do some research into how the sensors and remote key pad(s) are wired. Then you should be able to figure out how much of the old wiring can be reused.

[CliffARobinson]

I echo ebaines for the most part, I just have two things to add which might not help much, but - I am a security alarm, security camera & home automation geek of the highest magnitude for what it's worth :)

In my experience with three different properties, ADT uses a lot of off the shelf equipment from companies like Honeywell Ademco, so it is possible you could end up using *some* units, if they exist, but like ebaines says, you need to identify the main box manufacturer and model to know for sure.

The wiring is standard for the most part, it comes in 22-gauge 2-wire and 4-wire, the 4-wire are usually fire detectors, as an example.

Having said that, while wired accessories are about 30% or more cheaper, wireless saves on the wiring headaches if you want to put monitors in different places. You could have a mixed wired/wireless system for expansion like I have. You just need to purchase a wireless receiver to place in your central box.

Sorry for rambling. Like I said, geek.

[Stratmando]

What system do have? Like mentioned above, all the wires to 1 location with existing panel allows most any panel to be installed, I can help with ANY system you have, may be able to use existing panel by defaulting and reprogramming.
Although 4 wires were mentioned for fire only, 4 wires are commonly used for smokes, motions, glass breaks, beams, expanders, receivers, and on and on.
2 conductors are comonly used for magnetic contacts. And then a end of line resistor is used to help stop cutting or jumping of zones.
ALL of the wiring can likely be reused.
Actually there are many 2 wire smokes.

Oh, and if you want to monitor yourself, for free, and have the ability to listen, and even talk back, I would check out United security Products, they have dialers that will call you directly and 7 others immediately.
However, If you are one of the majority, you will pay someone for the ability for them to listen in on you, with a delay, They now call the house first, due to overwellming number of false alarms caused by The Big Companies hiring cheap help, and not training end user proper techniques.
One problem is if someone is forced to disarm under Duress, Usually you enter a different code, this way it disarms AND silently sends a duress signal.
Due to the Call Back Now, The Monitoring station may call back, and actually tell the intruder, YOU TRIGGERED THE ALARM. YOU TRIED TOO RAT ME OUT.
I can't believe Incompetence by installers, now leaves people more vulnerable?
Progress?
I wouldn't place receiver in control panel, I would have it centrally located(wider range, better reliability.
I prefer Hardwired, but have the receiver to protect the shed in the back, and my Vehicles have Door/window transmitters so at night, If I hear the Van chime, I know it Imediatley, The DSC Keypad in the office has 4 chime tones.
Front door is one sound, garage door another, shed is 1 sound as well as the Van.
Also allows Keyfobs for arming and Lights if automation board is added.