Frequently Asked Questions about Smoke Alarms

If your smoke alarm is chirping regularly, it may be as simple as the battery needs replacing. While it’s now recommended smoke detectors are hardwired to a home’s power supply, many still run primarily off batteries – or perhaps have a backup battery power supply. When you hear chirping or beeping replace the battery immediately. It should be replaced every 12 months, regardless.

Alternatively, dust or bugs inside the alarm may be impacting the efficiency and internal signals. This is why it should be cleaned at least once a year. Poor wiring could also be blamed, which is why a professional electrician should always install a smoke alarm for your safety.

Old alarms previously detected heat using internal elements, which are triggered when a certain temperature is reached. However, modern smoke alarms work differently by reacting to smoke. There are two main types, which work as follow:

Photoelectric: Using a light source and a photoelectric sensor, when smoke enters the alarm, the light beam is interrupted and scattered. The newly scattered beam then hits the sensor, triggering the alarm. Often a preferred alarm for picking up slow burning, smouldering fires.

Ionisation: Containing a small, harmless amount of radioactive material, ionisation smoke detectors pick up smoke particles in the air. When the smoke passes through the alarm it disturbs the ionisation process, activating the alarm. It’s very effective for fast acting, raging fires.