A smoke detector, just a few weeks in operation, today produced false alarm. There was no one in the apartment, no smoke or heat or the like. The neighbors were startled, in turn startled us on the road, and did almost get the fire department. I had this smoke detector chosen because with them the error rate (so far) very low to almost non-existent seemed. That changes now probably so slow, if you read the recent feedback. The excitement of the neighbors and us, or even an unnecessary Feuerwehreinsatz I feel already as very annoying.
Addendum 03.11.2015: A second of five smoke alarms went tonight at 01.00 clock in the nursery going, would not that there smoke or heat, or else had happened. Except then annoyed family members.