Why do smoke detectors randomly go off?

This can cause smoke to be emitted for a period of time and possibly set off smoke alarms. Dirt, drywall dust and construction debris is often present in ductwork. First use of the furnace can cause fine particles to be blown through the house possibly causing nuisance alarms. read more

High humidity in the air can set off smoke alarms. The density of the moisture particles in the air trigger the alarm. The device has no way of distinguishing between light smoke particles and heavy moisture content. Insects. Small insects can crawl into the smoke detector itself and set off the alarm. read more

The photoelectric smoke detector sensor detects smoldering flames that give off lots of smoke, but very few flames. Learn more about the dangers of ionization-only smoke detectors in NBC’s story Some Smoke Detectors May Not Go Off In Time. read more