Fire alarms are the first line of defence in detecting fires early and alerting people to evacuate. Whether installed in commercial premises, industrial sites, or residential buildings, fire alarm systems are critical for saving lives and protecting property. However, when fire alarms fail, the consequences can be catastrophic.
In the UK, compliance with fire safety regulations such as the Regulatory Reform (Fire Safety) Order 2005 and BS 5839 requires businesses and landlords to ensure their fire alarm systems are properly installed, maintained, and operational at all times. Despite this, false alarms, non-activation, and complete system failures remain common issues in many buildings.
In this blog, we explore the most common reasons fire alarms fail and provide practical guidance on how to prevent these failures from happening.
Why Is Fire Alarm Reliability So Important?
- Early Warning Saves Lives: A functioning fire alarm system alerts occupants to evacuate before conditions become life-threatening.
- Prevents Property Damage: Early detection allows time to suppress a fire, reducing potential damage and loss.
- Legal Compliance: Non-functional alarms can lead to fines, enforcement notices, and criminal prosecution under UK fire safety law.
- Insurance Validity: Insurers may reject claims if a non-functioning fire alarm contributes to the extent of a fire.
Common Reasons Fire Alarms Fail
1. Poor Maintenance
Regular maintenance is not only a best practice—it’s a legal requirement under BS 5839-1 (for commercial systems) and BS 5839-6 (for residential systems). Neglecting maintenance can lead to:
- Dust build-up in smoke detectors, causing false alarms or preventing detection.
- Corroded wiring and connections, leading to system malfunctions.
- Sensor failure, which renders alarms ineffective.
Warning Signs:
- Frequent false alarms.
- Unresponsive alarm testing.
- Intermittent fault signals or beeping.
How to Prevent Poor Maintenance Issues:
- Schedule regular servicing by a qualified fire alarm engineer, at least every 6 months for commercial properties (as per BS 5839-1).
- Perform weekly testing to confirm sounders and visual alarms are working correctly.
- Clean detectors to prevent dust or insects from interfering with sensors.
- Keep maintenance records for compliance and inspections.
2. Battery Failures
For battery-operated and backup battery systems, battery failure is one of the leading causes of alarm malfunction. In domestic properties, smoke alarms powered solely by batteries often fail due to:
- Batteries running flat.
- Batteries being removed to stop nuisance alarms and not replaced.
- Poor quality or expired batteries that lose charge unexpectedly.
Warning Signs:
- Chirping or beeping sounds indicating low battery.
- Alarm not sounding during routine tests.
How to Prevent Battery Issues:
- Test alarms weekly and replace batteries immediately if they fail the test.
- Replace disposable batteries at least once a year, even if they appear functional.
- Choose alarms with sealed long-life batteries (10-year lifespan) to reduce the risk of tampering or neglect.
- Ensure backup batteries in mains-powered alarms are regularly tested and replaced as needed.
3. Incorrect Installation
Improper installation is a common cause of fire alarm failure, especially in buildings where systems have been retrofitted or installed by non-qualified individuals. Issues can include:
- Incorrect placement of detectors, causing delayed response or false alarms (e.g., installing smoke detectors too close to kitchens or bathrooms).
- Insufficient coverage, leaving high-risk areas without proper detection.
- Improper wiring and connections, which may fail when alarms are needed most.
Warning Signs:
- False alarms in areas prone to steam, dust, or cooking fumes.
- Detection blind spots, where smoke doesn’t reach sensors quickly.
- Alarm zones not triggering correctly during testing.
How to Prevent Installation Errors:
- Always use a qualified, third-party accredited installer (e.g., BAFE-registered) for fire alarm systems.
- Ensure installation complies with BS 5839-1 for commercial buildings or BS 5839-6 for homes.
- Conduct commissioning tests to ensure all alarm zones and devices work as intended.
- Review the fire risk assessment to confirm detectors are correctly positioned based on the building’s layout and risks.
4. Ageing or Outdated Systems
Fire alarm systems have a finite lifespan. Over time, sensors become less sensitive, components degrade, and the system becomes unreliable. Most fire alarms should be replaced or upgraded after 10-15 years, depending on the environment and manufacturer guidance.
Warning Signs:
- Frequent faults that are difficult to repair.
- Difficulty sourcing replacement parts.
- Reduced reliability during testing.
How to Prevent Failures in Old Systems:
- Review the system’s age and consult with a fire safety professional about system life expectancy.
- Consider upgrading to modern addressable systems for better monitoring and control.
- Replace old detectors and control panels with newer, more reliable technology.
- Schedule annual assessments to plan for upgrades before the system fails.
5. Lack of Staff or Occupant Training
Even the best fire alarm system can fail to protect people if staff or residents do not know how to respond. In some cases, staff ignore alarms or disable them due to misunderstanding or nuisance alerts.
Warning Signs:
- Alarms ignored during drills or actual emergencies.
- Unauthorised tampering with detectors or panels.
- Delays in evacuating when alarms activate.
How to Prevent Human Error and Tampering:
- Provide fire safety training to all staff, including how to respond to alarms and evacuate.
- Regularly hold fire drills to reinforce correct behaviour.
- Appoint trained fire wardens to oversee evacuations and check that systems remain functional.
- Ensure fire alarm panels are in secure, monitored areas to prevent tampering.
The Importance of Regular Fire Risk Assessments
The Regulatory Reform (Fire Safety) Order 2005 places a legal duty on businesses and landlords to conduct fire risk assessments. These assessments should:
- Identify potential fire hazards, including alarm system deficiencies.
- Confirm that fire detection and alarm systems are appropriate and functional.
- Recommend corrective actions, such as system upgrades or additional staff training.
Fire risk assessments should be reviewed regularly or when there are significant changes to the building or its use.
Legal Compliance: What UK Law Requires
Under UK fire safety regulations, including the Fire Safety Order 2005, the responsible person must:
- Ensure the building has appropriate fire detection and warning systems.
- Maintain fire alarms in efficient working order.
- Keep records of maintenance and testing for inspection by enforcing authorities.
- Provide fire safety information and training to staff.
Failure to comply can result in enforcement notices, fines, and potential prosecution if lives are put at risk.
Don’t Let Fire Alarm Failure Put Lives at Risk
Fire alarms are critical to life safety, but they can only protect people and property if they work correctly. Poor maintenance, battery failure, incorrect installation, outdated systems, and human error are the leading causes of fire alarm failure—yet all are preventable.
Key Takeaways
- Test fire alarms weekly and service them twice a year.
- Replace batteries regularly and avoid cheap or expired products.
- Ensure alarms are installed by qualified professionals and meet BS 5839 standards.
- Replace ageing systems before they fail.
- Provide fire safety training and carry out regular fire drills.
At Martyn Young Fireproofing Consultancy, we offer comprehensive advice on fire protection and prevention to ensure your building stays protected and compliant with UK fire safety regulations.
Contact us today to arrange a fire alarm inspection or learn more about our fire safety services.