Ade Optima Compact Keeps Beeping Zone 3

[Walker007]

Hi all, had this system a few years now been working absolutely fine now when setting it’s just beeping and zone 3 just flashing and the system will not set at all unless I omit the zone 3? Any help on this? 

[james.wilson]

Zone 3 is open. You need to investigate why. What is on zone 3