Step 1:

            Remove one battery of control panel, wait 5 minutes

Step 2:

            Press and hold "up arrow" button and insert battery, “ENTER CODE” will appear

Step 3

            Release "up arrow" button and press "KEY" button ("quick" on HA2000T)

Step 4

            System will reset all code and the alarm will be armed

Step 5

            Press 0000 and "OK"  button to disarm system