What happens when a fixed temperature heat detector is activated?

When a fixed temperature heat detector is activated, it typically signals that the temperature threshold it was designed to monitor has been surpassed, usually indicating the presence of a fire. Unlike smoke detectors, which may reset after conditions stabilize, a fixed temperature heat detector is designed to respond to a specific, predetermined temperature. Once activated, the components within the detector undergo a physical change, often a change in state, that cannot be reversed.

As a result, the activated detector usually must be replaced to ensure the fire alarm system is fully operational and capable of detecting future heat events. This replacement ensures the continued effectiveness of the fire safety system since a deactivated or damaged detector can lead to a dangerous situation where fires may not be detected promptly in the future.