Kidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Alkaline Battery Back-Up c/w Quick Fit BaseKidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Battery Back Up The Kidde KF21 Sentry Optical Smoke Alarm is a reliable mains powered smoke detector designed to provide early warning of slow, smouldering fires within residential properties. Featuring an advanced optical sensor, the KF21 is ideal for hallways, landings, bedrooms, living areas and loft spaces, helping to improve fire safety throughout the home. This interconnectable smoke

Kidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Battery Back-Up

The Kidde KF21 Sentry Optical Smoke Alarm is a reliable mains-powered smoke detector designed to provide early warning of slow, smouldering fires within residential properties. Featuring an advanced optical sensor, the KF21 is ideal for hallways, landings, bedrooms, living areas and loft spaces, helping to improve fire safety throughout the home.

This interconnectable smoke alarm can be linked with up to 23 compatible Kidde FIREX smoke, heat and carbon monoxide alarms, ensuring that when one alarm detects danger, all connected alarms sound simultaneously for maximum protection.

Designed with installers in mind, the KF21 includes a Quick-Fit Slide-On Base for fast and tidy installation, while the 150mm flared base plate neatly covers marks left by larger existing alarms during retrofit projects.

Key Features

• Mains-powered optical smoke alarm with 9V alkaline battery back-up
• Interconnects with up to 23 compatible Kidde FIREX alarms
• Advanced optical sensor for detecting slow, smouldering fires
• Quick-Fit Slide-On Base for rapid installation
• 150mm flared base plate for clean retrofitting
• Integrated cable management for secure and tidy wiring
• Alarm memory identifies the triggered alarm within the network
• Combined Test/Hush button for testing and silencing nuisance alarms
• Auto reset following alarm activation
• Tamper-resistant locking mechanism
• Suitable for lofts, hallways, bedrooms and living rooms
• Fully compatible with Kidde FIREX smoke, heat and CO alarms
• 10-year manufacturer warranty

Ideal Applications

The Kidde KF21 optical smoke alarm is suitable for installation in:

• Hallways and circulation routes
• Bedrooms
• Living rooms
• Attics and loft spaces
• Residential properties requiring Grade D2 fire detection

Optical smoke alarms are particularly effective at detecting slow-burning fires caused by upholstery, electrical faults or cigarettes, making them ideal for living spaces and escape routes.

Technical Specifications

• Model: KF21
• Power Supply: 230V mains with 9V alkaline battery back-up
• Sensor Type: Optical with dust compensation and bug screen
• Alarm Volume: Minimum 85dB at 3 metres
• Alarm Frequency: 3.2 kHz typical
• Interconnectivity: Up to 23 compatible alarms
• Alarm Grade: D2
• Approvals: BSI certified to BS EN14604:2005
• Dimensions: 150mm x 53mm
• Weight: 295g including battery
• Operating Temperature: -10°C to +40°C
• Humidity Range: Up to 93% RH non-condensing
• Warranty: 10 Years

Compliance & Installation

The Kidde KF21 complies with UK Building Regulations and BS 5839 Part 6 requirements for Grade D domestic fire alarm systems. Installation should be carried out by a qualified electrician. For kitchen installations, a dedicated Kidde FIREX heat alarm is recommended instead of a smoke alarm.

Downloads

Data Sheet:
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Instruction Manual:
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