Interlinked Smoke Alarm System UK¶
Everything you need to know about interlinked (interconnected) smoke alarm systems for maximum UK fire safety compliance.
What Is an Interlinked Smoke Alarm System?¶
An interlinked smoke alarm system connects all alarms in a property so that when one detects smoke or heat, every alarm sounds simultaneously. This provides earlier warning for occupants, especially in multi-storey homes or flats. Building Regulations Approved Document B and BS 5839-6 have required interlinked alarms in new properties since 2022. Systems can be hardwired (physical cable between units) or wireless (radio-frequency). Popular UK options include Aico RF and hardwired ranges, FireAngel Thermistek and Ei Electronics RadioLINK. A full interlinked system for a 3-bed house costs £120-£300 depending on the number of units and wiring requirements.
Wired vs Wireless Interlinking - Pros and Cons¶
Hardwired interlinking uses a three-core interconnect wire between alarms. It is extremely reliable with no signal interference, but installation is more invasive and expensive, typically £150-£250 for a professional install. Wireless systems like Aico RadioLINK use RF modules (300m range, 868MHz frequency) and are far easier to retrofit, costing £80-£180 for a DIY setup. Wireless is ideal for existing homes where running cables is impractical. Both methods can mix smoke, heat, and CO alarms on the same network. Aico's RF system supports up to 12 devices and uses encrypted communication to prevent cross-talk between neighbouring properties.
Specifications and Comparison¶
| Interlinking Method | Installation Cost | Best For | Max Devices |
|---|---|---|---|
| Hardwired (3-core) | £150-£250 | New builds, renovations | 20+ |
| Wireless RF (radio) | £80-£180 | Retrofits, existing homes | 12-20 |
| Hybrid (wired + RF) | £200-£350 | Large properties | 30+ |
FAQ¶
- Do all smoke alarms in a house need to be interlinked?
- For new builds and properties with a material change of use, yes - Building Regulations require interlinked alarms. For existing homes, it is strongly recommended but not legally required.
- Can I mix different brands in an interlinked system?
- Only if the brands use a compatible interconnect protocol. Aico, Ei Electronics and FireAngel each have proprietary RF systems. Hardwired interconnect may work if pin assignments match.
- How do I test an interlinked alarm system?
- Press the test button on any one alarm - all linked units should sound within 10 seconds. Test weekly and replace batteries annually. For more information see our Smart Smoke Alarm Setup Guide UK.
Last updated: 2026-05-31.
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