Alarm

I have a 2010 340 that is plugged into shore power. There is some kind of alarm that is going off and I can’t figure out what it is. There’s no water in the bilge, both engines start just fine, and I’m showing that the shore power is working fine. I have no idea what this alarm is trying to tell me, but it won’t stop even when I shut down all the breakers. Suggestions?

Is it 2 or 3 beeps, then silent for about a minute or two, then repeats?

I had this "alarm" my first winter of owning our 420. It was the CO Detectors. After speaking with several "old salts", they said they always unplug (remove power) from them for the winter. You can remove the cover and disconnect the power plug.

Jaybeaux