Welcome to Part 3 of our 14-day fire safety series.
False fire alarms disrupt businesses, worry residents and can reduce confidence in an important life-safety system. They can also place avoidable pressure on fire and rescue services.
Most false fire alarms have an identifiable cause. Common examples include dust, steam, cooking vapour, aerosols, unsuitable detector selection, building work, system faults and user error.
The answer is not to cover, remove or permanently disable detectors. The correct approach is to investigate the cause, record the event and correct the underlying problem.
What is a false fire alarm?
A false fire alarm is an alarm signal caused by something other than an uncontrolled fire.
This may include:
- Cooking fumes or burnt toast.
- Steam from showers, kettles or industrial processes.
- Dust from building work.
- Aerosol sprays.
- Cigarette smoke or vaping.
- A faulty detector or wiring problem.
- Accidental operation of a manual call point.
- Incorrect testing or maintenance procedures.
- A detector that is unsuitable for its environment.
A detector is designed to respond to signs associated with fire. Smoke, vapour, dust and aerosols can sometimes look similar to the sensor. The alarm may therefore be working as designed, but the system may not be correctly matched to the environment.
For more information about local fire safety responsibilities, read the guidance from North Wales Fire and Rescue Service.
1. Identify the cause before resetting the system
When an alarm activates, follow the building’s fire action plan.
Treat every alarm seriously. Evacuate where required. Do not delay an evacuation to investigate. Only trained and authorised personnel should investigate the cause, and only where it is safe to do so.
Once the situation is safe:
- Check the fire alarm control panel.
- Note the zone, detector or manual call point shown.
- Check the affected area for smoke, heat, flames or a burning smell.
- Consider recent activities in that location.
- Contact the fire alarm maintenance provider if the cause is unclear.
- Record the event in the fire alarm logbook.
Do not simply silence and reset the alarm without checking what happened. The panel information can help identify the source. Repeatedly resetting the system may hide a developing fault or remove useful information for an engineer.
If there are signs of a genuine fire, leave the building and call 999. Do not assume that an activation is false because the same detector has activated before.
2. Control dust and debris
Dust is a common cause of unwanted fire alarms. It can enter detector chambers and affect their operation. Construction, drilling, sanding, cutting, decorating, ceiling work and ventilation maintenance can all create airborne particles.
Take these steps before work begins:
- Inform the responsible person for fire safety.
- Review the work method and likely dust levels.
- Protect nearby detectors using suitable temporary covers where approved.
- Isolate affected zones only through an agreed procedure.
- Arrange a fire watch or other suitable temporary protection where necessary.
- Notify the alarm receiving centre before testing or approved isolation.
- Remove all temporary covers as soon as work finishes.
- Arrange detector cleaning and inspection after dusty work.
Never leave detectors covered after the work is complete. A covered detector cannot provide normal protection.
Building contractors must also understand that dust can travel through corridors, ceiling voids and ventilation systems. Work in one room may affect detectors elsewhere in the building.
3. Manage steam and cooking vapour
Steam from bathrooms, showers, kettles, dishwashers and industrial processes can trigger smoke detectors. Cooking fumes and burnt toast are also frequent causes of false fire alarms in homes, offices, care settings and commercial premises.
Review areas where detectors are close to:
- Kitchens and kitchenettes.
- Toasters, hobs and ovens.
- Bathrooms and shower rooms.
- Canteens and catering facilities.
- Laundry rooms.
- Industrial equipment that releases vapour.
- Poorly ventilated spaces.
Do not move or remove a detector yourself. A competent fire alarm professional should assess whether the detector is correctly positioned and whether the detector type is suitable.
A heat detector may be more appropriate in some kitchen environments. A multi-sensor detector may be suitable in other locations. The correct choice depends on the fire risk, room use, ventilation and system design.
A smoke detector may still be necessary in areas where early smoke detection is important. Avoid making changes simply to stop nuisance alarms. Any change must maintain the required level of fire protection.
4. Keep aerosols away from detectors
Deodorants, hairsprays, cleaning products, spray paint and other aerosols can activate smoke detectors when used nearby.
This can happen in:
- Bathrooms and changing rooms.
- Bedrooms and student accommodation.
- Care homes.
- Hotel rooms.
- Offices with cleaning activities.
- Workshops and maintenance areas.
Use clear signs where appropriate. Tell staff, residents, visitors and contractors not to spray products directly beneath or close to a detector.
Cleaning teams should also understand the location of fire alarm devices. Spray products should not be directed towards detectors, vents or other sensitive equipment.
If a detector regularly activates after aerosol use, log the pattern and ask a competent engineer to review the location. The solution may involve staff communication, improved ventilation or a change to the system design.
5. Check whether the detector is suitable
Every room has a different environment. A detector that works well in an office may not be suitable for a kitchen, workshop or plant room.
A professional review should consider:
- The room’s current use.
- Temperature and humidity.
- Air movement and ventilation.
- Dust, fumes and vapour.
- Cooking or manufacturing processes.
- Sleeping accommodation.
- Changes made since the original installation.
- The type and sensitivity of the detector.
- The location of nearby doors, vents and equipment.
Room use can change over time. An office may become a staff kitchen. A storage room may become a workshop. A domestic room may be converted into a utility area.
The fire alarm system should be reviewed when the use of a space changes. The original detector selection may no longer be appropriate.
6. Investigate faults and maintenance issues
False fire alarms can result from equipment faults. Possible causes include:
- Contaminated detector chambers.
- Ageing or damaged detectors.
- Loose connections.
- Wiring faults.
- Battery problems.
- Control panel faults.
- Incorrect system settings.
- Damage caused by contractors.
- Poor previous repairs.
- Inadequate servicing.
Regular fire alarm maintenance helps identify these issues before they become repeated failures.
A competent engineer can test detectors, inspect the control panel, check batteries and wiring, review system history and assess whether devices are operating correctly. The engineer can also identify patterns that may not be obvious to building users.
The Fire Industry Association recommends regular inspection and servicing based on the system, environment and risk. North Wales businesses should maintain accurate service records and follow the recommendations for their installation.
Dragon provides fire alarm installation, maintenance and monitoring services for commercial, industrial, public sector and residential properties.
7. Improve staff and occupant communication
User error is a preventable cause of false fire alarms.
Staff, residents and contractors should know:
- What to do when the alarm sounds.
- Who is responsible for the system.
- How to report an activation.
- How to arrange a system test.
- When to contact the alarm maintenance provider.
- Which activities may create smoke, dust or vapour.
- Why detectors must never be covered or removed.
- How to record events in the fire alarm logbook.
Tell contractors about the fire alarm system before work starts. Include alarm procedures in induction information. Keep emergency contact details current.
Testing must follow the agreed process. If the system is connected to an alarm receiving centre, notify the centre before testing or maintenance. This helps prevent avoidable responses and ensures that genuine alarm signals remain clear.
8. Keep a useful false alarm log
A logbook should record more than the date of an activation.
Include:
- Date and time.
- Location.
- Detector or manual call point.
- Activities taking place at the time.
- Weather or environmental conditions, where relevant.
- Whether smoke, heat or fumes were found.
- Actions taken.
- Engineer attendance.
- Repairs or adjustments completed.
- Any changes to procedures or training.
Patterns often become clear after several entries. For example, activations may occur at the same time each morning when cooking begins. They may happen only during refurbishment or after cleaning products are used.
Use the information to improve the system and the way the building is managed.
9. Never disable fire protection as a shortcut
Frequent false alarms are frustrating. Disabling detectors is not a safe solution.
Do not:
- Remove detector heads.
- Cover detectors indefinitely.
- Disconnect zones without authorisation.
- Silence alarms without investigating.
- Alter settings without professional advice.
- Ask unqualified people to repair the system.
- Ignore repeated activations.
Temporary isolation may be necessary during approved work, but it must be controlled, recorded and supported by suitable alternative precautions. The system should be restored as soon as the work is complete.
Professional help with fire alarm systems in North Wales
The best way to reduce false fire alarms is to combine good management with professional fire alarm maintenance.
Dragon Security & Electrical Ltd can help with:
- Fire alarm servicing.
- Detector cleaning and testing.
- Fault-finding.
- System inspections.
- Detector replacement.
- System upgrades.
- Alarm monitoring.
- Maintenance planning.
- Advice for commercial and domestic properties.
If your system is activating repeatedly, do not wait for the next disruption. Ask for the cause to be investigated.
You can contact Dragon through the website contact page or call 01492 330330.
For related information, read our guide to BS 5839-1:2025 and fire alarm system changes.
False fire alarms should be treated as a management issue, not an unavoidable inconvenience. Investigate each activation, record the findings, maintain the system and review detector suitability whenever the building or its use changes.
Reliable protection starts with a system that is correctly designed, properly maintained and understood by the people who use the building.