How do you enter programming on a LYNX Plus L3000?

To enter programming mode on a Honeywell LYNX Plus L3000 alarm control panel, press your four digit installer code + [800]. The default installer code is [4112]. If you do not know the installer code, you may still be able to access the programming mode of the L3000. With your LYNX Plus disarmed, unplug the AC cord, and the battery from the system, completely cutting power and shutting it down. Re-apply power to the LYNX Plus and within the first 60 seconds, press and hold the [*] & [#] keys until a 20 flashes on the screen. You can then change the installer code by pressing [*20] and entering a new four digit code so you can re-enter programming mode in the future without having to power down your L3000.