What is the most common cause of false alarms?

The single most common cause of unprompted false alarms in residential smoke detectors is the accumulation of environmental airborne contaminants—such as household dust, pet dander, cobwebs, and tiny microscopic insects—clogging the optical sensor chamber. In photoelectric smoke alarms, these particles scatter the internal infrared light beam in the same manner as smoke smoke particles, tricking the microprocessor into sounding a full alarm. Other frequent causes include steam and humidity condensing from nearby showers or kitchen cooking. You can troubleshoot false alarms safely by pressing the central silence button. You can verify that your corrective action is successful when removing the smoke detector from its ceiling bracket and cleaning the optical chamber thoroughly with compressed air eliminates dust interference and stops recurrent false alarms permanently.