How to reduce false alarms (unwanted fire signals)

Direct answer

Most false alarms (unwanted fire signals) are caused by environmental factors, unsuitable detector selection or siting, and lack of maintenance. You can reduce them by choosing the right detector type for each area, siting detectors away from steam, dust and fumes, keeping the system maintained, and investigating and recording the cause of every false alarm. For repeated problems, review detector type (for example multi-sensor instead of optical) and consider filtering or verification features available on the system.

Applies to

• Products / Models: All Hochiki Europe detectors and panels (general guidance)

• Firmware / Version: Not applicable

• Region: UK / Europe

• Standards: BS 5839-1 (false alarm management)

Common causes

• Cooking fumes, steam and high humidity near optical smoke detectors.

• Dust and aerosols, insects, or condensation in the detector chamber.

• Detector type or siting not suited to the environment.

• Lack of maintenance or contamination over time.

How to reduce false alarms

1. Select the appropriate detector type for each area

   • Consider multi-sensor detectors in areas prone to transient smoke or steam.

   • Use heat detectors where smoke detection is unsuitable (for example kitchens).

2. Site detectors correctly

   • Keep detectors away from sources of steam, fumes, dust and rapid air movement.

3. Maintain the system

   • Keep to the servicing regime; clean or replace contaminated detectors.

4. Investigate and record every false alarm

   • Record the device, location and likely cause to identify recurring problems.

5. Review system features

   • Where available, review detector sensitivity settings, day/night modes and alarm verification options with a competent person.

When to contact technical support

• If false alarms recur from the same device or area after the steps above.

• If you need advice on detector selection or sensitivity configuration.

Safety note

This article is general guidance for Hochiki Europe products. Installation, commissioning, maintenance and modification of fire detection and alarm systems must be carried out by a competent person in accordance with the applicable standards (for example BS 5839-1 in the UK) and the requirements of the relevant authority having jurisdiction. Always refer to the current product manual and data sheet for the exact model before carrying out any work.

References

• BS 5839-1 (current edition) — false alarm management

• Relevant detector data sheets (sensitivity / mode options)

Last reviewed: 2026-06-16 — Reviewed by: Takashi Ishikawa