Hi RobW and welcome to our forum,
To check if your system has the default program code, press *8 9713.
If the Program Code is valid, the “Service” LED will flash and the five function LED’s (Stay, Chime, Exit, Bypass, and Cancel) will illuminate steadily. If this is found true, exit program mode by pressing EXIT.
If 9713 is not accepted, then there is a chance that the download code is the default one (84800000). To check it out, the panel must be connected to a land line. I could dial your panel and see if the download code is the default and if it is, I could reset only the master (to 1234) and the program (to 9713) codes, without altering the whole system configuration and that would be just it.
If the download code is changed also, then you have to buy an NX-568E interface and I could reset all three codes through the internet. Read the following topic for details:http://www.diysecurityforum.com/index.php?topic=13725.0
Another option would be you buy a program called NXunlocker ( http://www.nxunlocker.com/
). It costs 99$. The program can reset the download code to the default one. Then you could change the program and master codes from within DL900 (GE/Caddx's downloading software). You would still need to buy the NX-586E interface.http://www.homesecuritystore.com/p-696-nx-586e-quick-link-connect.aspx