Date: August 23, 2019 The smoke detector model P1210E went off this morning for no apparent reason: no smoke, no humidity, no showers running, no appliances running in the house, no heater/heat pump. No changes in lighting. The date on the inside is stamped 2019 Apr 01. The other smoke detectors sensed nothing. This unit was purchased to replace an older model as a safety precaution in June 2019. I count on product reliability, especially with a smoke detector. Malfunctions are unacceptable.