Fire alarm maintenance frequency
How often fire alarm systems must be serviced under BS 5839-1, what factors can increase the required frequency, and the consequences of missed or delayed service visits.
BS 5839-1 sets a minimum servicing frequency of twice per year — but for many premises and system types, more frequent servicing is recommended or required. Understanding what drives the required frequency, and the consequences of falling behind on maintenance, is essential for anyone responsible for fire alarm compliance.
Minimum Servicing Frequency Under BS 5839-1
For most non-domestic fire alarm systems, BS 5839-1 recommends a minimum of two inspection and test visits per year — commonly referred to as six-monthly servicing. These visits must be carried out by a competent specialist contractor and must cover all the inspection and testing requirements set out in the standard.
The two visits should be spaced approximately six months apart — not both in the same quarter and not more than nine months apart. An annual gap between service visits is not compliant with the standard’s intent, even if two visits technically occur within a twelve-month period.
For new systems, the first service visit should ideally occur six months after commissioning, with subsequent visits at six-monthly intervals from that date.
When more frequent servicing is needed
Factors That Increase Servicing Requirements
BS 5839-1 recommends more frequent servicing in certain circumstances. Six-monthly is the minimum — not the target — and the following factors should prompt a review of whether quarterly or more frequent visits are appropriate:
High false alarm rate
A system generating frequent unwanted alarms suggests detectors may be contaminated, incorrectly positioned, or failing. More frequent servicing enables the underlying cause to be identified and addressed before a pattern becomes entrenched.
Harsh environment
Systems installed in dusty, humid, corrosive, or high-temperature environments — factories, food processing facilities, chemical plants — degrade more quickly than those in clean office environments. Quarterly servicing is often appropriate.
High-risk occupancy
Premises with vulnerable occupants — care homes, hospitals, schools — or with high fire risk should consider quarterly servicing to minimise the window during which a developing fault could go undetected.
Large or complex system
A large addressable system with hundreds of devices may benefit from quarterly visits to ensure all devices are covered in a planned testing rotation and that no area is left untested for an extended period.
Consequences of missed servicing
What Happens if Servicing Lapses
Missing a service visit is not a minor administrative oversight — it has real consequences for system reliability, legal compliance, and insurance:
| Consequence | Detail |
|---|---|
| Undetected faults | Faults that would have been identified at a service visit remain undetected, potentially for months. A system with undetected faults may fail at the worst possible moment |
| Legal non-compliance | The Regulatory Reform (Fire Safety) Order requires fire precautions to be maintained in efficient working order. A lapsed service schedule is evidence of non-compliance and can result in an enforcement notice |
| Insurance implications | Many commercial property insurance policies require six-monthly servicing as a condition of cover. A missed service visit may give the insurer grounds to dispute or reject a claim following a fire |
| Battery degradation undetected | Standby batteries are tested at service visits. Without servicing, a degraded battery may go undetected until a mains failure leaves the system with insufficient backup capacity |
First year servicing
A Note on New System Servicing
A common misconception is that a newly installed fire alarm system does not need servicing in its first year. This is incorrect. BS 5839-1 requires the first periodic service visit to take place within the first year of operation — ideally at the six-month point. New systems are not immune to faults, and the commissioning process, however thorough, does not substitute for periodic maintenance.
Common questions
Frequently Asked Questions
BS 5839-1 recommends a minimum of two visits per year for most systems. Annual servicing does not meet this recommendation for a standard non-domestic Grade A system. In very limited circumstances — simple systems in very low-risk premises — a risk-based argument for annual servicing might be made, but this would need to be explicitly justified in the fire risk assessment and agreed with the insurer. For the vast majority of commercial premises, two visits per year is the minimum.
No — in fact, the case for maintaining the normal servicing schedule is stronger when a building is unoccupied. An unoccupied building with a faulty fire alarm system is at greater risk because there are no occupants to notice or report developing faults. If the building is monitored by an ARC, the ARC may detect panel faults — but this does not substitute for physical inspection and testing. The six-monthly service schedule should be maintained regardless of occupancy status.