Best Smoke & Carbon Monoxide Alarms for Flats
Working smoke and carbon monoxide alarms are the single most important safety kit in any flat. UK rules require a smoke alarm on each storey and a CO alarm in rooms with a fuel-burning appliance — but whether you rent or own, it’s worth making sure yours are present, modern and tested. This guide rounds up reliable, easy-to-fit alarms for flats.
QUICK ANSWER
Fit a sealed 10-year-battery optical smoke alarm on each level of your flat, and a carbon monoxide alarm in any room with a boiler, gas hob, fire or other fuel-burning appliance. Sealed 10-year units need no battery changes; test them monthly. In a rented flat, your landlord is responsible for providing them — but check they work.
Who this guide is for
Every flat dweller. Especially useful if your alarms are old, missing, or battery types you keep having to replace — and for renters checking their flat is properly protected.
Our picks at a glance
| Pick | Product | Best for |
|---|---|---|
| BEST SMOKE ALARM | FireAngel Optical Smoke Alarm FA6620 (10-Year) | Fit-and-forget smoke protection |
| BEST SMOKE 2-PACK | FireAngel Optical Smoke Alarm (2-Pack, 10-Year) | Covering a whole flat at once |
| BEST SMOKE VALUE | X-Sense Smoke Alarm | Affordable, dependable cover |
| BEST CO ALARM | FireAngel Carbon Monoxide Alarm | Reliable CO protection |
| BEST CO BRAND | Kidde 5CO Carbon Monoxide Alarm | A well-known CO specialist |
| BEST CO DIGITAL | X-Sense Carbon Monoxide Detector | A clear digital readout |
How we chose
We compared these products on the features that matter for UK flats — size, practicality, running or maintenance needs, renter-friendliness and value — using published specifications and brand reputation. We haven’t tested every product hands-on, and we don’t quote prices or star ratings here because they change; tap through to Amazon for the current figures and reviews.
The best smoke and carbon monoxide alarms for UK flats
FireAngel Optical Smoke Alarm FA6620 (10-Year)
Best for: Fit-and-forget smoke protection
FireAngel is a leading UK alarm brand, and this optical smoke alarm has a sealed 10-year battery so there’s nothing to replace — ideal for hallways and landings where flats need cover.
Pros
- Trusted UK alarm brand
- Sealed 10-year battery
- Optical sensor (good for smouldering fires)
- No battery changes
Cons
- Replace the whole unit after 10 years
- One per storey needed
FireAngel Optical Smoke Alarm (2-Pack, 10-Year)
Best for: Covering a whole flat at once
A twin pack of the same sealed 10-year FireAngel optical alarms — a cost-effective way to cover the hallway and another level or room in one go.
Pros
- Two alarms for value
- Sealed 10-year batteries
- Cover multiple areas
- Reliable brand
Cons
- Still replace after 10 years
- Not interlinked by default
X-Sense Smoke Alarm
Best for: Affordable, dependable cover
A budget-friendly smoke alarm from X-Sense with a photoelectric sensor and long-life battery, offering dependable cover at a lower price.
Pros
- Affordable
- Photoelectric sensor
- Long-life battery
- Simple to fit
Cons
- Check battery/lifespan spec
- Fewer smart features
FireAngel Carbon Monoxide Alarm
Best for: Reliable CO protection
A FireAngel carbon monoxide alarm to place near boilers, gas hobs and fires, warning you of this invisible, odourless gas with a loud alarm and long sensor life.
Pros
- Trusted brand
- Detects invisible CO
- Long sensor life
- Easy to place or mount
Cons
- Needs siting near fuel appliances
- Replace at end of sensor life
Kidde 5CO Carbon Monoxide Alarm
Best for: A well-known CO specialist
Kidde is a major name in fire and CO safety, and this CO alarm offers dependable detection with a clear alert — a reassuring choice for a flat with gas.
Pros
- Established safety brand
- Reliable CO detection
- Clear alarm
- Simple to use
Cons
- Basic display on some versions
- Sensor has a finite life
X-Sense Carbon Monoxide Detector
Best for: A clear digital readout
An X-Sense CO detector with a digital display showing CO levels, useful if you want to see readings as well as hear an alarm.
Pros
- Digital CO-level display
- Affordable
- Long battery life
- Easy to place
Cons
- Display drains battery faster
- Still needs periodic replacement
How to choose
- Where to fit: A smoke alarm on each storey (hallways/landings), and a CO alarm in any room with a boiler, gas hob, fire or fuel-burning appliance.
- Sealed 10-year batteries: These need no battery changes for a decade and can’t be left flat — the most hassle-free choice.
- Optical/photoelectric smoke sensors: Good at detecting the smouldering fires common in homes; site away from kitchens to reduce false alarms.
- Test monthly: Press the test button once a month, whoever provides the alarm.
- Renters: In England, landlords must provide a working smoke alarm on each storey and a CO alarm where there’s a fixed combustion appliance — rules vary across the UK. Report any missing or faulty alarms.
Frequently asked questions
Does my flat legally need smoke and CO alarms?
In England, landlords must provide a working smoke alarm on each storey of a rented home and a carbon monoxide alarm in any room with a fixed combustion appliance; rules differ across the UK nations. Whether you rent or own, every flat should have working smoke alarms and a CO alarm where there’s a fuel-burning appliance.
What’s the difference between a smoke and a carbon monoxide alarm?
A smoke alarm detects smoke from fire; a carbon monoxide alarm detects CO, an invisible, odourless gas produced by faulty fuel-burning appliances. They protect against different dangers, so you need both where relevant — one is not a substitute for the other.
Are sealed 10-year alarms better?
For most people, yes. A sealed 10-year-battery alarm needs no battery changes and can’t be disabled by removing a battery, so it’s more reliable and hassle-free. You replace the whole unit at the end of its life.
Our recommendation
Fit FireAngel sealed 10-year optical smoke alarms (single or the twin pack) on each level, with the X-Sense as a budget option. For CO, choose the FireAngel or Kidde alarm near fuel appliances, or the X-Sense digital model if you want a live readout.
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