top of page

How Fire Alarms Work

Fire Alarm Control Panel

Fire alarms are a part of our daily lives, so much so that we rarely consider how they work. Let us take a moment to follow the process a Fire Alarm System goes through when it is activated.

Alarm is Tripped by Initiating Devices

First, Initiating Devices such as smoke detectors, heat sensors, fire sprinkler waterflow switches or manually-activated pull stations are triggered. Initiating devices, with the exception of manually-activated pull stations, are triggered by changes in their environment. For instance, smoke detectors are triggered when smoke enters the device, heat detectors activate when there is either a certain rate of change in room temperature or when a room reaches a certain temperature, and waterflow switches take note of flowing water in the sprinkler pipes, indicating an activated sprinkler head.

Signal Sent to Control Panel

Tripped Initiating Devices, such as those mentioned above, send a signal to the Fire Alarm Control Panel. The panel then activates notification devices within the building and the 24-hour monitoring center.

Occupant Notification

Strobes, horns, and Voice Evacuation Speakers are all types of devices used to notify building occupants of an emergency. The size, occupancy, and use of a building determines which combination of notification devices are used.


The monitoring station contacts the authorities to dispatch emergency services and contacts the business owner or designated emergency contact. It is essential to keep emergency contacts updated with your monitoring center and alarm company to ensure the proper person can be reached during an emergency.

While these steps are listed separately, many happen almost simultaneously. The moment the alarm is tripped your fire alarm system quickly activates occupant notifications and sends out the signal to monitoring.

To learn more about the parts listed here, check out our post on the 5 Main Parts of a Fire Alarm System!


bottom of page