Smoke Detector Malfunctions

History of Smoke Detectors

• Smoke detectors were first invented in the 1930s. However, in 1890, two inventors in Massachusetts sought to create a fire-warning system. Using magnets, a battery and a bell, the device alerted occupants if the temperature in a building rose above a certain level. In 1930, another inventor, in attempting to create a detection system for poison gas, found that he had invented a system for detecting smoke. This invention led to other advancements in the field of fire protective technology, and by the mid 1970s, Americans were beginning to buy smoke detectors for home use.

Ionization Smoke Detectors

• Ionization detectors operate similarly to older smoke detectors. However, in modern ionization detectors, two electrically charged metal discs are set close together in the detector chamber. Radioactive material is placed between them, ionizing the air and causing a current to flow through the plates. As smoke moves into the chamber, this ionizing process is disrupted and the alarm goes off.

Photoelectric Smoke Detectors

• The other main type of smoke detector is a photoelectric smoke detector. In these models, a light is shone into the sensor chamber; however, it does not shine at the sensor. Whenever smoke enters the chamber, the smoke displaces the light and forces it onto the sensor, triggering the alarm.

Malfunctions in Smoke Detectors

• Since ionization detectors go off when something disrupts the flow of ions, dust, dirt and other small particles can sometimes activate the smoke detector. If your smoke detector is malfunctioning, try dusting it with a cloth; then vacuum the detector or spray with compressed air. If this does not fix the problem, inspect the detector for bugs or other obstructions.

  Since the alarm of the photoelectric detector is triggered by the displacement of light, make sure the detector is far away from your kitchen or other cooking area. Burning food, smoldering butter or pan-fried foods can easily create smoke that will set off these detectors. If your photoelectric detector is malfunctioning, clean it and ensure it is placed in a well-ventilated area.

Other Malfunctions

• If cleaning the smoke detector does not solve a malfunction, change the battery. Test the detector with the new battery in place. If the detector still malfunctions, consider testing the detector. You can use canned smoke to spray into the detector chamber, a magnet to trigger the discs or a special telescoping rod to activate the smoke detector. If your detector continues to malfunction, consider purchasing a new unit. The National Fire Prevention Association recommends testing smoke detector systems once every 6 months.