TEST CO and Smoke Detectors MAINS

For Westermill Consideration Only
CO and Smoke Detectors Mains vs Batteries

In the UK, the requirements for carbon monoxide (CO) and smoke alarms in rental cottages with wood burners, specifically regarding whether they need to be mains-powered or can be battery-operated, are outlined by various regulations and standards.

Smoke Alarms
  • The Smoke and Carbon Monoxide Alarm (England) Regulations 2015: These regulations do not specify that smoke alarms must be mains-powered. Therefore, landlords can use either mains-powered or battery-operated smoke alarms as long as they are properly installed and maintained.

  • Building Regulations (Approved Document B): For new builds and significant refurbishments, the regulations typically require mains-powered smoke alarms with battery backup. However, for existing rental properties, battery-operated smoke alarms are generally acceptable if they meet the required standards.

Carbon Monoxide Alarms
  • The Smoke and Carbon Monoxide Alarm (England) Regulations 2015: Similar to smoke alarms, these regulations do not mandate that carbon monoxide alarms must be mains-powered. Battery-operated CO alarms are acceptable if they comply with British Standards (BS EN 50291).
Specific Requirements and Recommendations
  • Installation and Placement:
    • Both smoke and CO alarms should be installed according to the manufacturer's instructions and positioned correctly to ensure optimal detection of smoke and carbon monoxide.
    • CO alarms should be installed in any room where a solid fuel-burning appliance (such as a wood burner) is located.
  • Maintenance:
    • Regular testing and maintenance of both types of alarms are essential. Landlords are responsible for ensuring alarms are in good working order at the start of each new tenancy.
    • Batteries should be checked and replaced as needed. Even if using battery-operated alarms, it is advisable to opt for long-life sealed battery units to reduce maintenance issues.
Advantages and Considerations
  • Mains-Powered Alarms:
    • Pros: They offer a continuous power supply and typically come with battery backup in case of a power outage.
    • Cons: Installation can be more complex and costly, especially in existing buildings not wired for such alarms.
  • Battery-Operated Alarms:
    • Pros: Easier and cheaper to install, especially in existing properties.
    • Cons: Require regular battery checks and replacements to ensure functionality.
Practical Application

For rental cottages with wood burners, while mains-powered alarms are generally recommended for new builds and major refurbishments, battery-operated alarms are acceptable and often used in existing properties due to their ease of installation and lower cost.


Both mains-powered and battery-operated smoke and CO alarms are permissible in rental cottages with wood burners under current UK regulations. However, it is crucial for landlords to ensure that whatever type of alarm is used, it must be installed correctly, regularly tested, and maintained to ensure the safety of the occupants.

For more detailed information, landlords can refer to the following resources: