A smart smoke detector does everything a standard alarm does — and then some. When smoke or carbon monoxide is detected, it sends a push notification to your phone, speaks to you in plain English, and can trigger automations across your wider smart home. With UK fire statistics showing that roughly half of all domestic fires occur at night when occupants are asleep, having an alarm that wakes you and alerts you remotely is a meaningful upgrade. This guide covers the five best smart smoke detectors on the UK market in 2026, plus the regulations every homeowner should understand before buying.
UK Regulations: What the Law Requires
BS 5839-6 is the key standard. This British Standard covers the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises. For most homeowners the relevant grade is Grade D — a network of interconnected, mains-powered smoke alarms with integral battery backup. New builds and material alterations must meet this minimum under Building Regulations Approved Document B (fire safety). The category LD2 placement requirement means at least one detector in every circulation space (hallways and landings) plus high-risk rooms. Scotland has its own stricter regime under the Housing (Scotland) Act 2014 as updated in 2022, requiring interlinked alarms in all rooms used as living accommodation.
For existing homes without rewiring, Grade F (battery-only, interlinked by radio) is still permitted under BS 5839-6, and the modern 10-year sealed-battery alarms in this guide meet that grade comfortably. If you are doing any renovation that involves electrical first-fix work, upgrading to Grade D mains units is strongly advised.
Smart vs Standard Smoke Detectors
The core difference is connectivity. A standard alarm sounds locally and nothing else. A smart alarm adds one or more of: Wi-Fi or Zigbee connectivity for remote notifications, voice announcements that tell you which room is affected, integration with smart home platforms, and — in some cases — combined carbon monoxide detection. The trade-off is cost (smart units typically run from around £35 to over £100 each) and, for Wi-Fi models, reliance on a working internet connection. For a broader overview of building out your security setup, see our guide to the best smart doorbells in the UK.
Top 5 Smart Smoke Detectors for UK Homes
1. Google Nest Protect — Best for App Notifications
Pros: Dual-sensor split-spectrum detection (fast and slow-burning fires); combined smoke and carbon monoxide alarm; speaks the location of the hazard aloud; Wi-Fi app alerts; Heads-Up early warning before full alarm. Cons: Premium price (typically around £100–£120 each in the UK); no official Home Assistant SDM API support for Protect devices (only Nest thermostats and cameras are currently exposed via the API); battery version does not meet Grade D for new builds.
The Nest Protect remains the gold standard for app-connected smoke and CO detection. It distinguishes between steam and smoke, whispers a Heads-Up warning before the full alarm sounds, and sends a push notification naming the affected room. Available as wired (mains) or battery versions — the wired version can count towards Grade D in a new installation alongside interlinked companions. Find Google Nest Protect on Amazon UK.
2. Aico Ei3016 — Best for New Builds and Electricians
Pros: 230 V mains with 10-year lithium rechargeable backup; Grade D1 compliant; RadioLINK wireless interlink via optional Ei3000MRF module; AudioLINK+ data extraction to smartphone; 85 dB(A) sounder; 10-year guarantee. Cons: No Wi-Fi or cloud app in the base unit; RadioLINK module sold separately; less polished consumer packaging than Nest.
Aico's Ei3016 is the alarm of choice for UK electricians fitting new builds and refurbishments to BS 5839-6 Grade D1. It uses optical detection and can interlink wirelessly with the full Aico 3000 series range — smoke, heat, and CO alarms — without any additional cabling. The AudioLINK+ feature lets you pull a diagnostics report directly from the sounder using a smartphone app, which is genuinely useful during annual testing. Find the Aico Ei3016 on Amazon UK.
3. Kidde FireX Mains (KF20) — Best Budget Mains Alarm
Pros: 230 V mains with 9 V alkaline battery backup; optical detection; hard-wired interlink with up to 23 Firex alarms; BSI certified to BS EN 14604:2005; test/hush button; meets Grade D BS 5839-6. Cons: No wireless interlink or app connectivity; alkaline backup battery (not sealed); basic feature set.
The Kidde FireX KF20 is a no-frills workhorse that ticks all the regulatory boxes for new builds at a considerably lower price per unit than Nest or Aico. It hard-wires to up to 23 other Firex alarms so that all units trigger simultaneously. If you want mains-grade protection without the premium, this is the practical choice — especially for landlords fitting multi-room systems. Find Kidde FireX Mains on Amazon UK.
4. X-Sense SD19-W — Best for Wireless Interlink Without Rewiring
Pros: 10-year sealed battery; wireless interlink of up to 24 units; 250 m open-air transmission range; photoelectric sensor; self-test every 60 seconds; very competitive price per unit. Cons: No Wi-Fi or app remote notifications; no CO detection; battery-only so Grade F rather than Grade D.
The X-Sense SD19-W fills a practical gap for homeowners who need a properly interlinked system throughout a large house but cannot or do not want to run new mains wiring. Up to 24 units communicate wirelessly — when one triggers, all sound. The 10-year sealed battery means no annual battery replacement faff. Note this is a Grade F system under BS 5839-6, which is acceptable for existing dwellings but not for new builds or major refurbishments. See X-Sense SD19-W at xsense.com or find it on Amazon UK.
5. Bosch Smart Home Smoke Detector II — Best for Bosch Ecosystem Users
Pros: Zigbee 3.0 connectivity; app push notifications via Bosch Smart Home app; networks with other Bosch Smart Home smoke alarms (all sound simultaneously); contamination compensation to reduce false alarms; replaceable 3 V lithium battery (up to 5 years). Cons: Requires Bosch Smart Home Controller (sold separately); no Amazon Alexa or Google Home integration; battery-only power supply; higher cost than X-Sense for similar detection capability.
If you already run a Bosch Smart Home setup, the Smoke Detector II integrates neatly — it uses Zigbee 3.0 and sends push notifications with room location via the Bosch app. Multiple units network together for simultaneous alarm activation. It does not currently integrate with Amazon Alexa or Google Home, and it does not work with Home Assistant's Nest integration (different protocol entirely). Find Bosch Smart Home Smoke Detector II on Amazon UK.
Interconnection Options
Wired interlink (used by Kidde FireX and Aico in hard-wired mode) carries a trigger signal along a dedicated wire — reliable and requires no RF spectrum. Wireless/RF interlink (Aico RadioLINK, X-Sense SD19-W) eliminates cabling and is ideal for retrofits. Wi-Fi/app interconnection (Nest Protect, Bosch) works differently — it's cloud-mediated, meaning remote notifications depend on your broadband being live. For life-safety purposes, any of the three wired or RF approaches is preferable to cloud-only interconnection.
Carbon Monoxide Detection
Only the Google Nest Protect in this list combines smoke and CO detection in a single unit. CO is odourless and kills quickly, so if you have gas appliances, a boiler, or an open fire, a combined smoke/CO alarm or a separate CO detector in each room with a fuel-burning appliance is strongly advised. BS 5839-6 does not mandate CO detection but references BS EN 50292 for placement guidance. If you are building a wider security setup, take a look at our smart home starter guide for the UK for advice on layering detection devices.
App Alerts and Smart Home Integration
Of the five picks, Nest Protect offers the richest smart home story — provided you manage your expectations about Home Assistant support. The Nest SDM API does not currently expose Protect devices, so HA users cannot read alarm state or trigger automations directly. Bosch Smart Home Smoke Detector II works within the Bosch ecosystem over Zigbee but lacks cross-platform support. X-Sense and Kidde FireX have no app integration. Aico's AudioLINK+ is a diagnostics tool, not a live notification system. If remote alerts are your primary requirement, Nest Protect is currently the only off-the-shelf option in the UK.
Verdict
For new builds and full rewires, the Aico Ei3016 is the most complete Grade D1 solution — professional grade, 10-year guaranteed, and RF-interlinkable without extra cabling hassle. For app connectivity and combined smoke/CO detection, the Google Nest Protect remains unmatched despite its premium price. Renters and homeowners who cannot rewire will find the X-Sense SD19-W the most cost-effective way to achieve whole-house wireless interlink. The Kidde FireX KF20 is the sensible budget option for mains-wired installs, and the Bosch Smart Home Smoke Detector II earns its place only if you are already invested in the Bosch ecosystem.
Related: best smart carbon monoxide detector, best home security system UK, and smart home security tips.
