You need to clear the non volatile memory and reset to factory set conditions, quite simple really. Power up the unit to alarm, then isolate mains supply to panel and remove battery. Obviously alarm now silent. Remove wires from terminal 17 (PA) and 27 (SET +) wire may not be connected to this terminal. Fit a wire link across the terminals 17 and 23+. The system will now power up with no alarm condition, remove wire link and restore wiring as original including connect the battery. Fit alarm box cover and check tamper light goes out. Gradually ALL zones will clear and the system will return to day mode. Now the NVMemory is clear and the unit has been reset to factory conditions.The system now requires reprogramming, remember Engineer code is 9999 and the user code is reset to 0123. Hope this helps as it worked when I replaced my 8EP219 remote keypad with a 8EP416 keypad. The 8EP416EU keypad is identical to the 8EP416 except that words on the keypad are replaced with symbols.
Helpfull Al, August 2010