It's not going off for no reason, it's just that you do not know how to interpret the information that the control panel is giving.
More information is needed, what circuit/zone number is showing, what if any lights are showing, if you can't remember have you looked at the log, the information is there.
Come back with more information, type of detectors, how many if more than one on each circuit, type of building, anything left switched on, does it always happen at the same time, etc etc etc? I could go on.
acorn, September 2009