We have a Galaxy 500 control panel in our office and have recently had a door removed and are unable to disable the zone that the door contact was programmed to. We can omit the zone but this needs doing every time the alarm is set and we would like to disable it permanently if possible. I only have access to user manual and this doesn't seem to show how to disable a zone. Due to the age of the system there is no current alarm company looking after it.