What is BS5839?
BS 5839 is the British Standard that sets out the guidelines for designing, installing, commissioning, and maintaining fire detection and alarm systems in buildings, ensuring they are reliable and suited to the specific risks of the premises.
BS 5839 is typically reviewed and updated every 5 to 10 years, but updates can occur sooner if significant industry changes, new technologies, or safety concerns arise.
BS 5839-1 was last updated in 2017, following a previous major update in 2013, and a now a new revision has been released for 2025.
What is new for BS5839-1 2025 revision?
BS 5839‑1:2025, which came into effect on 30 April 2025, updates the 2017 edition with clearer guidance and enhanced safety measures—extending detection to lift shafts and low-risk lobbies, requiring distinct lockdown tones, 90-second signal monitoring, updated battery backup calculations, and mandatory red mains cable labelling; it also reinforces maintenance protocols by mandating 6-month service flexibility (5–7 months), CPD for engineers, battery recording, clock sync, zone chart updates, and removal of obsolete components, along with refreshed certification templates, a new section for system modifications, and modernised terminology to improve inclusivity and clarity.
But that is not all. BS5839-1:2025 now also makes specific mention of the latest Linear Heat Detection standards BS EN 54-22 and BS EN54-28.
What are BS EN 54-22 and BS EN 54-28?
A BS EN standard ensures the UK uses the same technical and safety requirements as other European countries, promoting consistency, quality, and easier trade across borders.
For example, BS EN 54 is a widely used European standard for fire detection and alarm systems.
BS EN 54-22 is defined as ‘fire detection and fire alarm systems – Part 22: Resettable line-type heat detectors.
BS EN 54- 28 is defined as ‘fire detection and fire alarm systems – Part 28: Non-resettable line-type heat detectors.
What Does BS5829-1:2025 say about using Linear Heat Detection?
The 2017 BS5829 revision recognised Linear Heat Detection as a suitable alternative to point-type heat detectors, particularly in areas where environmental conditions (e.g. dust, high ceilings, or heat) make point detectors unsuitable.
Clause 22.3(l) of BS 5839-1 notes that linear heat detection may be used in difficult environmental conditions, such as cable tunnels, industrial spaces, and transport infrastructure.
However, the BS5839-1:2025 revision makes clear recommendation for using Linear Heat Detection in enviornmental harsh conditions and will lead to less unwanted and false alarms (clause 33.2.2)
Which applications should Linear Heat Detection be used in?
Linear heat detection should be used in environments where traditional point detectors are unsuitable, such as:
- Harsh or dirty environments (e.g. tunnels, factories, cable trays)
- Areas with high ceilings or long distances (e.g. warehouses, conveyors)
- Hazardous or explosive areas
- Outdoor or exposed locations
- When early heat detection along a continuous path is needed
It’s ideal where precise, continuous temperature monitoring is critical and conditions may affect standard detectors.
For examples of where Signaline Linear Heat Detection can be used please check out our applications pages.
Which Signaline Linear Heat Detection cables are approve to BS5839-1:2025?
Please note that BS5839-1 is an installation standard and not a product standard. However, to comply to the installation standard approved products must be used. BS5839-1:2025 makes specific mention of BS EN54:22 and BSEN54:28 as discussed above.
Our approved products to these standards are as follows
Signaline HD+ is our Programmable Linear Heat Detector that is approved to EN54:22 (please click here for the certificate)
Signaline FT-EN is our Non-Resettable Linear Heat Detector that is approved to EN54:28 (please click here for the certificate)
Summary
BS 5839-1:2025 is the updated British Standard for fire detection and alarm systems, effective from 30 April 2025. It offers improved guidance on system design, installation, commissioning, and maintenance, with a focus on enhanced safety and clearer requirements. The revision formally references BS EN 54-22 and BS EN 54-28, endorsing Linear Heat Detection (LHD) for challenging environments like tunnels and hazardous areas. Approved products such as Signaline HD+ and Signaline FT-EN are recommended to ensure compliance.
For further information on BS5839 or on our Signaline Linear Heat Detection cables please contact sales@lgmproducts.com