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Home Safety & Fire Protection · Accessories & Add-ons

Smoke & Carbon Monoxide Alarms: What Else You'll Need

By the Nest & Yard editorial teamUpdated 2026-08-093 min read

Our pick: the FireAngel Optical Smoke Alarm 2-Pack — FA6620 10-Year Battery Smoke Alarms for Home with Test/Silence Button, Replacement for FireAngel ST-622/ST-620 — the best Smoke & Carbon Monoxide Alarms we tested, from £22.16.

Protecting your home from smoke and carbon monoxide requires more than just the alarm itself – ensuring it’s properly fitted and maintained is crucial for its effectiveness. This guide explores essential accessories and consumables that often get overlooked when setting up a smoke or carbon monoxide alarm, covering everything from wall mounts and extending cables to protective cases and spare batteries. Considering these supplementary items alongside your chosen alarm can significantly enhance your home's safety setup and provide peace of mind.

See the full range in Smoke & Carbon Monoxide Alarms.

Pros

  • Twin pack covers two rooms in one purchase
  • Sealed 10-year lithium battery, no replacements needed
  • Test/silence button for easy false-alarm hushing

Cons

  • Standalone units, no wireless interlink between the two alarms
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FireAngel FA6620 Optical, Battery Powered Fire/Smoke Alarm for Home, 10-Year Battery
Best Budget

#2 Pick

FireAngel FA6620 Optical, Battery Powered Fire/Smoke Alarm for Home, 10-Year Battery
Rated 4.3 out of 5 stars (12,666)
  • Standalone
  • 10 years

£11.98

Pros

  • Sealed 10-year battery, no replacements needed
  • Very high review volume backs up reliability claims
  • Replacement model for the popular ST-620/ST-622 series

Cons

  • Standalone unit, no wireless interlink with other alarms
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Kidde 10LLDCO Ten Year Life Carbon Monoxide Alarm, Digital Display with Sealed Longlife Battery
Best Value

#3 Pick

Kidde 10LLDCO Ten Year Life Carbon Monoxide Alarm, Digital Display with Sealed Longlife Battery
Rated 4.6 out of 5 stars (3,871)
  • Standalone
  • 10 years

£22.94

Pros

  • Digital display shows live CO readings at a glance
  • Sealed 10-year battery removes the need for replacements
  • 10-year manufacturer warranty backs the sensor life

Cons

  • Slightly pricier than a basic indicator-light CO alarm
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Kidde 7DCOC Carbon Monoxide Alarm, White

#4 Pick

Kidde 7DCOC Carbon Monoxide Alarm, White
Rated 4.6 out of 5 stars (3,521)
  • Standalone
  • 2 years

£18.25

Pros

  • Digital display shows live CO readings
  • Loud 85dB alarm with test button
  • Trusted long-standing safety brand

Cons

  • Requires AA batteries, not sealed for 10-year life
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FAQ

What's usually included in the box with a new smoke alarm?

Typically, you’ll find the alarm unit itself, mounting fixings (screws and wall plugs), an instruction manual, and possibly a battery. However, it often doesn't include a test button cover or any spare batteries – so check these aren’t missing.

Do I need to buy a different type of battery?

Most alarms use 9V batteries, but some newer models utilize AA or AAA batteries; always confirm the required battery type before purchasing your alarm.

What if my smoke alarm doesn't have a test button cover?

A test button cover protects the button from dust and accidental activation, which can be easily purchased separately to maintain functionality.

Should I buy spare batteries proactively?

It’s highly recommended to purchase a pack of spare 9V batteries (or the appropriate battery type) to ensure continuous operation if your alarm needs replacing.

Are there any specific mounting accessories I might need?

Depending on your wall construction, you may require additional adhesive pads or sealant for a more secure fit, particularly with plasterboard walls.

Do all smoke alarms require professional installation?

While many alarms are designed for DIY installation, some models – especially interconnected systems – might benefit from electrical expertise to ensure proper wiring and connectivity.

What if I need to replace the mounting screws?

Ensure you purchase replacement screws that are compatible with your wall type; different screw sizes and materials are suitable for various constructions.

Are there any accessories to improve the sound of the alarm?

While not essential, some users find a louder external siren or amplifier useful for alerting occupants in larger homes or noisy environments.

Do I need to factor in the cost of extending the range of interconnected alarms?

If you're installing multiple interconnected alarms, consider purchasing range extenders to maintain communication between them throughout your property.

What if my alarm needs replacing due to a fault after a short period?

Refer to the manufacturer’s warranty details for information on product defects and potential replacements; typically, Amazon handles returns according to their standard terms.

In depth

Let’s explore the supplementary items frequently required alongside smoke and carbon monoxide alarms for UK homes. Often overlooked during initial purchase, these accessories can significantly enhance the system's functionality and overall safety.

Many alarm installations begin with the core device itself – the sensor that detects dangerous gases – but a comprehensive safeguarding strategy necessitates consideration of additional components. Firstly, there’s the matter of mounting. While some alarms come with basic wall fixings, different surfaces (plasterboard, brickwork, smooth walls) require varied methods for secure installation. Supplementary fixing kits, often including various screw types, adhesive pads, or even template plates for precise positioning, are frequently needed to ensure a stable and reliable connection. It’s crucial to assess the installation surface before committing to a single fixings solution; a robust mounting is paramount for accurate gas detection.

Then there's the issue of power. While battery-operated alarms offer convenience and portability, they require periodic replacement. Consider stocking up on spare batteries – typically AA or 9V depending on the model – alongside a small storage container to maintain an adequate supply. It’s also wise to investigate whether the alarm features a low-battery warning signal; if so, ensure you have readily available replacement batteries before the original unit alerts you to its depleted state. Furthermore, some systems incorporate mains power options, and in these cases, a spare fuse or extension cable might be prudent to safeguard against electrical issues.

Beyond immediate installation needs, ongoing maintenance is key to alarm performance. This includes consumables like test buttons – alarms require regular testing to confirm they’re functioning correctly – and replacement detectors. Smoke alarms have a finite lifespan (typically 10 years), while carbon monoxide alarms usually last around 5-7 years depending on the manufacturer. Keep a record of purchase dates for each unit, allowing you to proactively replace them before their expiry date. Alongside this, consider purchasing cleaning supplies specifically designed for alarm sensors – dust and debris can significantly impede detection capabilities.

Furthermore, effective monitoring relies on clear communication. Many alarms feature integrated sirens, but backup solutions are advisable. Consider investing in a loud personal alarm or ensuring you have a designated escape route clearly marked with hazard signs. It’s also useful to maintain a readily accessible checklist of alarm testing procedures – this can be particularly helpful for homeowners unfamiliar with the system or for those who live alone.

Finally, think about broader environmental factors. Areas prone to high humidity or condensation may require additional protective measures, such as sealant or damp-proofing around the alarm housing to prevent corrosion and ensure long-term operational integrity. Regular visual inspections of the alarm unit itself are also recommended – check for signs of damage, dust accumulation, or any other irregularities that could compromise its performance. Maintaining a proactive approach to both installation and ongoing care will significantly contribute to the overall effectiveness of your smoke and carbon monoxide alarm system, providing invaluable protection for you and your family.

The Nest & Yard editorial team

Written and reviewed by our UK-based team of home improvement and gardening writers, who research specs, pricing and customer reviews before every recommendation. Reviewed and updated on 2026-08-09.

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