Wireless Fire Alarm Systems: The Complete UK Installer's Guide 2026

Wireless fire alarm systems have moved from "acceptable compromise" to first-choice specification on a growing share of UK commercial jobs, and this guide is written for the installers quoting them. Whether you are pricing a Category M call-point system for a small industrial unit, an L2 design for an HMO, or a phased refit of a listed building where cabling is the enemy, this hub pulls the whole subject together: what BS 5839 asks for, what EN 54-25 radio equipment must deliver, and how the Ajax EN54 Fire Hub Jeweller range - stocked at Netview in Leicester for same-day dispatch - covers the full device list from detectors to visual alarm devices.

What this guide covers

What a wireless fire alarm system is and where it wins against wired
BS 5839-1 categories (M, L1-L5, P1-P2) in plain installer language
The EN 54 parts that matter for radio-linked systems, including EN 54-25
Ajax's two fire tiers: EN54 Fire Hub commercial systems vs FireProtect 2 on a security hub
Detector, sounder, VAD and manual call point picks - with stocked SKUs
Range planning with Fire ReX, standby batteries, and intruder-system integration

Wireless fire alarm systems UK installer guide - Ajax EN54 Fire Hub — No cable pulls, no lifted floors: an EN 54-certified fire system that installs in hours, not days.

What is a wireless fire alarm system?

A wireless fire alarm system replaces the loop cabling of a conventional or addressable system with a certified radio link between the control panel and every detector, sounder and call point. The panel end is still a proper CIE (control and indicating equipment) with the same certification obligations as a wired panel - the difference is that commissioning a device means enrolling it over the air rather than terminating a cable. On the Ajax EN54 line, the EN54 Fire Hub Jeweller plays that CIE role, supervising every field device over the two-way Jeweller radio protocol. Radio-linked does not mean uncertified or "domestic grade": the standard that governs it, EN 54-25, demands supervised two-way links, jamming detection and battery fault reporting, which is exactly what separates a compliant commercial system from a DIY smoke alarm kit.

Are wireless fire alarms BS 5839 compliant?

Yes - BS 5839-1 accepts radio-linked systems, provided the components meet the EN 54 family of product standards, with EN 54-25 covering the radio transmission components themselves. Compliance lives in the design, not the cable: the categories, zoning, sound levels and standby requirements of BS 5839-1 apply identically whether signals travel down a loop or over 868 MHz. The current edition of the standard is BS 5839-1:2025, and the Fire Industry Association publishes a free guidance note on the 2025 changes that belongs in every fire installer's bookmarks. For dwellings the parallel standard is BS 5839-6, which is where the domestic tier of the Ajax fire range (covered below) earns its keep.

BS 5839-1 categories in plain language

The category defines where detection goes, and it is the first thing to agree with the client and the fire risk assessor - before any kit is chosen. The table below is the quick reference for non-domestic premises under BS 5839-1.

Category	Coverage	Typical premises
M	Manual call points only - no automatic detection	Small workshops and units where staff raise the alarm
L5	Detection in specific areas identified by the risk assessment	Targeted risk rooms - plant rooms, server rooms
L4	Escape routes - corridors and stairways	Minimum life-safety detection on the way out
L3	Escape routes plus rooms opening onto them	Offices, smaller hotels and guest houses
L2	As L3 plus defined high-risk rooms	HMOs, mid-size hotels, care settings
L1	Automatic detection throughout the building	Sleeping-risk premises - care homes, large hotels
P1 / P2	Property protection - whole building (P1) or defined parts (P2)	Insurer-driven specifications, stock and asset protection

Wireless shines at the M and L5-L2 end of that table, where a handful of devices in the right places gets a building compliant in a single visit. There is no wireless-specific category - the radio system simply has to deliver the same coverage the category demands.

The two Ajax fire tiers: which one is your job?

Ajax now sells two distinct fire lines, and picking the right one is the single most important spec decision in this guide. The EN54 Fire Hub line is a standalone, EN 54-certified commercial fire system; FireProtect 2 detectors are life-safety devices that live on an Ajax security hub and suit dwellings under BS 5839-6. They are not interchangeable, and the EN54 fire devices do not enrol on a security hub (or vice versa).

	Ajax EN54 Fire (commercial)	Ajax FireProtect 2 (domestic tier)
Panel	EN54 Fire Hub Jeweller (dedicated CIE)	Ajax security hub (Hub 2 / Hub 2 Plus)
Certification	EN 54-2, EN 54-4, EN 54-21, EN 54-25	EN 14604 / EN 50291 device standards
Standard context	BS 5839-1 (non-domestic)	BS 5839-6 (dwellings)
Typical jobs	Offices, HMO common parts, retail, industrial, heritage	Homes and flats already on an Ajax intruder system
Stocked picks	Full device list below	FireProtect 2 RB (Heat/Smoke/CO) - FireProtect 2 SB (Heat/Smoke/CO)

On the domestic tier, the RB models run up to 7 years on replaceable batteries and the sealed-battery SB models up to 10 years, with dual-spectrum smoke sensing, two thermistors and a chemical CO sensor in the combined models, per the Ajax FireProtect 2 product page. If the site already runs an Ajax intruder system - see our complete Ajax wireless alarm guide - adding FireProtect 2 devices is a ten-minute enrolment job.

EN54 Fire Hub Jeweller: the wireless CIE

The Fire Hub is the brain of the commercial system: a wall-mounted CIE with a large touch display that handles alarms, faults, zoning and test modes without a laptop. It is certified to EN 54-2 (control and indicating equipment), EN 54-4 (power supply equipment), EN 54-21 (alarm transmission) and EN 54-25 (radio components), and a single hub supervises up to 200 devices across 40 zones, per the Ajax EN54 Fire Hub product page. Connectivity for monitoring and remote service runs over Ethernet, Wi-Fi and dual SIM. Netview stocks the hub in white and black, with the GlandBox accessory where surface cabling needs a tidy entry. For a deeper walk-through of the panel itself, read our Fire Hub Jeweller installer guide.

Choosing detectors: smoke, heat and sounder combinations

The detector decision is the familiar one - smoke where you can, heat where smoke would false-alarm - with one wireless twist: Ajax builds sounder variants of both, which often removes the need for separate alarm devices in smaller rooms. All EN54 FireProtect detectors use a dual-spectrum optical sensor for smoke and communicate with the CIE at up to 1,700 m in open space, per the EN54 FireProtect (Smoke/Sounder) specifications.

Device	Detects	Fit it where
EN54 FireProtect (Smoke)	Smoke (EN 54-7)	Offices, corridors, bedrooms - the default detector
EN54 FireProtect (Heat)	Heat (EN 54-5)	Kitchens, dusty workshops, steamy areas
EN54 FireProtect (Smoke/Sounder)	Smoke + built-in sounder (EN 54-3)	Rooms needing detection and audibility in one head
EN54 FireProtect (Heat/Sounder)	Heat + built-in sounder	Kitchens and utility rooms on sleeping-risk jobs

Sounders on the same CIE synchronise their alarm automatically, and the system supports coincidence (double-knock) confirmation where two detectors must trigger before a full alarm - a genuinely useful weapon against false alarms on marginal sites. For the false-alarm story across the wider Ajax fire range, see our HazeFlow 2 deep-dive.

Three wireless fire alarm system builds - Category M, L4/L3 office and L2 HMO — Three reference builds on one platform: Category M unit, L4/L3 office, and L2 sleeping-risk premises.

Sounders and VADs: getting heard and seen

Where the detector-sounder combos do not cover the audibility plan, the dedicated alarm devices take over - and the VAD variants matter more than ever on jobs with hearing-impaired occupants or high ambient noise. The range gives you a wall-mount Sounder in white, the same unit in red, a combined Sounder/VAD with synchronised strobe, and a standalone VAD for visual-only coverage. All are battery-powered wireless devices supervised by the Fire Hub, so adding one to a noisy plant room after commissioning is an enrolment, not a rewire.

Manual call points: the Category M backbone

Every BS 5839-1 system from Category M upwards needs call points on exits and escape routes, and the wireless version removes the classic pain of surface trunking runs to every final exit. The Ajax ManualCallPoint (Red) Jeweller meets EN 54-11 and EN 54-25 and runs up to 7 years on its pre-installed batteries, per the Ajax product page. Netview also stocks the blue and green housings for non-fire signalling uses such as door release or spill alerts, plus reset keys for service kits. A Category M design - Fire Hub, call points at the exits, sounders in the circulation spaces - is often a one-day install with this kit.

Range planning: Fire ReX and real buildings

Open-space radio figures are generous - up to 1,800 m hub-to-device on the Fire Hub, per the Ajax specifications - but concrete floors, steel mezzanines and foil-backed insulation all take their cut, so survey with a signal test before you promise coverage. Where a wing or floor sits outside reliable range, the EN54 Fire ReX Jeweller range extender re-broadcasts the Jeweller link to distant device groups, per the Fire ReX product page - the standard fix for L-shaped industrial estates and multi-block schools. The practical rule: one Fire Hub per building where possible, Fire ReX for the awkward wings, and always a walk-test from the worst-case device location at survey stage.

Standby power: the 24-hour and 72-hour question

BS 5839-1 expects a fire system to keep working through a mains failure, and on the Ajax EN54 line that resilience is a battery selection rather than a calculation exercise. The Fire Hub takes an internal 24-hour backup battery or the larger 72-hour battery, giving 24 or 72 hours of autonomous operation depending on the option fitted, per the Ajax EN54 Fire Hub page. Field devices carry their own multi-year batteries, individually supervised by the CIE with low-battery faults reported per device - which turns the annual service visit into a targeted battery swap rather than a guessing game. Spec 72 hours where the premises can stand empty over a weekend; unmanned mains failures are exactly when property-protection systems earn their fee.

Integrating fire with intruder and automation

The commercial fire system stays certified precisely because it stands alone - but that does not mean it lives in isolation. The EN54 I/O Module (2x2) gives the Fire Hub two supervised inputs and two outputs for third-party interfaces: door holders, plant shutdown, AOV triggers or a signal to the intruder side. Coming the other way, an Ajax security hub can take wired third-party devices through the MultiTransmitter, and sites that pair fire detection with security deterrence increasingly add Ajax Ready security fog on the intruder system. For domestic and small-commercial security-plus-fire jobs, the Build Your Ajax System configurator prices the whole basket in one pass.

Why installers pick wireless over wired

The honest economics: wireless trades a higher parts price for a dramatically lower labour and disruption bill, and on occupied or heritage sites that trade wins. No lifted carpets, no fire-stopping every cable penetration, no weekend working around tenants; a phased refit can run floor by floor with the old system live until handover. Listed buildings and temporary structures - marquees, site cabins, decant space - are natural wireless territory, and when the client moves, the system unenrolls and moves with them. Wired addressable still makes sense on large new-builds where containment is going in anyway; for most refit and small-commercial work, the maths now favours radio.

How Netview supports fire installers

Netview is an authorised Ajax stockist based in Leicester, holding the EN54 fire range - hubs, detectors, sounders, VADs, call points, extenders and batteries - alongside the full Ajax intruder line for same-day dispatch on trade orders. Browse the fire protection range, drill into the EN54 detector range and manual call point range, or see every brand we carry. Trade accounts get trade pricing on the whole basket - order online at netviewcctv.co.uk.

Six step wireless fire alarm design and install workflow — From risk assessment to certificated handover: the six-step wireless fire workflow.

Wireless fire alarm FAQ: real installer questions

Are wireless fire alarm systems legal in the UK?
Yes. BS 5839-1 accepts radio-linked systems built from EN 54-compliant components, with EN 54-25 covering the radio parts. The Regulatory Reform (Fire Safety) Order requires appropriate fire precautions; it does not mandate cable.

Do wireless systems need less maintenance than wired?
They need the same BS 5839-1 servicing regime - typically six-monthly visits - but fault-finding is faster because the CIE supervises every device and battery individually and names the failing unit.

How many devices can one EN54 Fire Hub support?
Up to 200 devices across 40 zones on a single hub, per Ajax's published specifications - comfortably beyond most small and mid-size commercial premises.

What happens if someone jams or blocks the radio?
EN 54-25 requires the transmission path to be supervised, and the Fire Hub raises a fault when a device stops responding or interference is detected. Jamming shows up as an event, not silence.

Can I mix Ajax fire and Ajax intruder devices on one hub?
No. The EN54 fire devices enrol only on the EN54 Fire Hub, and intruder devices only on the security hubs. Interfacing between the two is done with the I/O Module on the fire side and MultiTransmitter or relays on the security side.

How long do the detector batteries last?
Multi-year, device-dependent - the ManualCallPoint runs up to 7 years on its pre-installed cells, per Ajax, and every battery is supervised so replacement is planned at service, not discovered at alarm.

Is a wireless system cheaper than a wired one?
Per device, no; installed, very often yes. You are trading hardware cost against cabling labour, containment, making-good and disruption - which is why occupied refits and heritage sites are where wireless quotes win.

What is the difference between FireProtect 2 and the EN54 FireProtect range?
FireProtect 2 detectors (RB/SB) are EN 14604 / EN 50291 devices for the Ajax security hubs - the right answer for homes under BS 5839-6. The EN54 FireProtect range works only with the EN54 Fire Hub CIE and carries the EN 54 part-certifications a commercial BS 5839-1 system needs.