Loud beeping / alarm sound from utility room

Hello everyone,

We bought a house last year that is about 10 years old.
It has an air-to-water heat pump from Buderus installed.

The day before yesterday, suddenly and without any visible reason, a loud alarm sounded (comparable to a smoke detector from the utility room). I happened to be in the utility room but couldn’t identify where the noise came from.
Just now the same sound went off again, this time about 15 times in a row. I still heard the last sounds in the room but again couldn’t exactly tell what was beeping. It sounded as if it came from the direction of the fuse box/electrical connection or water connection. The heat pump is on the other side of the room and shows no errors or anything. There are no smoke detectors etc. installed.
What could it be?
Who should I call, plumber, electrician?
Any ideas?

Best regards

Is the system being maintained?

She probably hasn't [been serviced] for 10 years. When we were there, we asked a local plumbing person to take a look at the heat pump. According to him, everything is fine (however, the sacrificial anode needs to be replaced), but we did not receive any service stamp or anything like that. Since nothing was ever wrong and we did not receive any invoice, I let it rest. Could the power connection/fuse box somehow be responsible for the beeping? Or is the problem more likely to be found in the area of water / air-water heat pump?

If available: Maybe lifting station or backflow preventer? The control unit of my backflow preventer beeps when maintenance is due.