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Combined smoke and CO alarm landlord rules in the UK

Updated: 21 October 2026

You are about to hand over keys, or you have just moved into a private let, and a combination alarm on the landing is being treated as the whole legal fit-out. Combined smoke and CO alarm rules for a landlord are four different statutes. The disc can count as the smoke point or the carbon monoxide point only in the room and the nation where that duty sits. It does not, on its own, satisfy Wales’s mains smoke alarms or Scotland’s interlinked layout. Cards and prices stay on the [smoke and CO detector comparison](/hub/fire-protection/smoke-and-co-detector). A qualifying purchase can earn a commission at no extra cost to you.

You are about to hand over keys, or you have just moved into a private let, and a combination alarm on the landing is being treated as the whole legal fit-out.

Our top picks

AEGISLINK AEGISLINK SC200

Best overall

AEGISLINK AEGISLINK SC200
7.7/10about £23.19
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X-Sense X-Sense SC07

Alternative

X-Sense X-Sense SC07
8.6/10about £27.71
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FireAngel FireAngel SCB10-R

Rank 3

FireAngel FireAngel SCB10-R
9.0/10about £29.99
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On this page
  1. 1.A combination alarm is not a UK-wide legal sticker
  2. 2.England since 1 October 2022
  3. 3.Scotland: interlinked fire alarms, and a combo only as an extra
  4. 4.Wales wants mains smoke; Northern Ireland follows a 2024 timetable

A combination alarm is not a UK-wide legal sticker

Each nation states where smoke must be, where carbon monoxide must be, and whether the smoke alarms must be mains and interlinked. A unit to BS EN 14604 and BS EN 50291 can fill one of those points when the duty allows it. The FireAngel SCB10-R, at about £29.99, prints a Kitemark and both EN numbers, and it does not interlink. How to read the listing is the buying guide.

England since 1 October 2022

From 1 October 2022 the England regulations cover private and social rented homes. You need a smoke alarm on each living storey, and a carbon monoxide alarm in any living room with a fixed combustion appliance other than a gas cooker. A fine can reach £5,000. One landing disc is not both duties when the boiler is in another room. Do not carry the gas-cooker exclusion into Wales, where a gas hob counts. A reported fault has to be repaired or replaced.
AEGISLINK AEGISLINK SC200

Testsieger

AEGISLINK AEGISLINK SC200
7.7/10about £23.19
View offer

Scotland: interlinked fire alarms, and a combo only as an extra

Every Scottish home is expected to have interlinked smoke alarms in the living room and circulation spaces, plus a kitchen heat alarm. Carbon monoxide detection is for a carbon-fuelled appliance other than a cooker or hob, and a battery model must be sealed for life. A combined detector may meet BS EN 14604 and BS EN 50291, but the smoke and heat alarms still have to interlink. A standalone FireAngel is not that layout, and Wi-Fi is not radio interlink.

Wales wants mains smoke; Northern Ireland follows a 2024 timetable

Wales requires mains smoke alarms on each storey, interlinked with each other, and a carbon monoxide alarm in each room with a gas, oil or solid-fuel appliance. A battery combo from this set does not replace that mains minimum. Northern Ireland private tenancies follow the Scottish fire layout from late 2024, with a sealed battery if the carbon monoxide alarm is battery-powered. The AEGISLINK 3-year cell fails that sentence. The 1–3 m measurement is on where to fit a combined alarm.

Common questions

Can one combination alarm meet both the smoke duty and the carbon monoxide duty?
Only when both duties sit in the same room and the nation allows that type of alarm there. A landing combo can be the smoke alarm for that storey in England. It is not the carbon monoxide alarm for a boiler in another room. In Scotland and Northern Ireland it is not the interlinked smoke and heat system. In Wales it is not the mains interlinked smoke alarm. The FireAngel SCB10-R can show both product standards and still fail those layout rules because it does not interlink.
Does England allow a battery combination alarm?
Yes, where a battery alarm is enough for that duty. The England regulations do not prescribe mains power for the private-rented smoke alarm on each living storey, and they do not ban a combination unit. You still need the carbon monoxide alarm in the room with the fixed combustion appliance, gas cookers excepted, and a reported fault has to be repaired. A sealed cell is preferred in the official guidance. It is not a reason to skip the second room.
Is a combination alarm enough for a Scottish home?
No. Guidance allows a combined detector that meets BS EN 14604 and BS EN 50291, and the carbon monoxide part need not be interlinked. The home still needs interlinked smoke alarms in the living room and circulation spaces, and a heat alarm in the kitchen. A sealed life battery is required for battery alarms, including carbon monoxide. An amazon standalone disc, including a Kitemarked FireAngel, does not replace that interlinked set. A Wi-Fi model is not the interlink.
Can a Welsh landlord skip mains smoke by fitting battery combos?
No. Wales requires mains smoke alarms on each storey, linked to each other. A battery combination alarm can appear in the records for a space it actually covers, and it does not remove the mains smoke minimum. Carbon monoxide alarms are still required in rooms with gas, oil or solid fuel, and a gas hob counts. Budget for an electrician for the smoke circuit, then decide whether a sealed combo is only the carbon monoxide point.
Do gas cookers need a carbon monoxide alarm?
It depends on the nation. England’s landlord duty excludes a gas cooker. Northern Ireland’s private-tenancy guidance excludes a gas cooker or oven. Wales treats a gas appliance as including a hob, so a kitchen hob can add a carbon monoxide alarm of its own. Scotland’s carbon monoxide trigger is a carbon-fuelled appliance other than a cooker or hob. Read the let’s nation before you copy an English cooker line onto a Cardiff inventory.
What did the 2022 English amendment add?
From 1 October 2022 the amended regulations cover social rented homes as well as private lets, require a carbon monoxide alarm for fixed combustion appliances other than a gas cooker, and require repair or replacement once a fault is reported. The smoke rule remains at least one alarm on each living storey. A penalty can reach £5,000.

Related pages

Best smoke and CO detector

Smoke and CO detector

Buying a smoke and carbon monoxide alarm in the UK

Where to fit a combined smoke and CO alarm in the UK

When a combined vs separate smoke and CO alarm fits

Sources

Public UK sources from the research digest, last checked on 19 October 2026. Prices, stars, and review counts are the amazon.co.uk lines captured that day.

  1. GOV.UK — Smoke and Carbon Monoxide Alarm (England) Regulations, landlord booklet (retrieved 19 October 2026)
  2. Approved Document B, volume 1, dwellings (retrieved 19 October 2026)
  3. Approved Document J circular, 2022 (retrieved 19 October 2026)
  4. Scottish Government — fire and smoke alarms in Scottish homes (retrieved 19 October 2026)
  5. Department for Communities — Northern Ireland private-tenancy alarms, 2024 (retrieved 19 October 2026)
  6. NHS — carbon monoxide poisoning (retrieved 19 October 2026)
  7. FireAngel SCB10 datasheet (retrieved 19 October 2026)