Kidde KF21R Mains Optical Smoke Alarm With Rechargeable Lithium Backup

The Kidde KF21R Sentry is a mains powered optical smoke alarm built for homes, rentals and new builds. The optical sensor is especially good at picking up slow, smouldering fires such as those started by soft furnishings, electrical faults or cigarettes.

If the mains supply fails, the sealed rechargeable lithium cell keeps the alarm working, so there are no batteries to change over its life. It can be interlinked with up to 23 compatible Kidde FIREX smoke, heat and carbon monoxide alarms so every alarm sounds together, and the Quick-Fit slide-on base makes installation and replacement fast and tidy.

Key Features

• Optical sensor - ideal for slow, smouldering fires
• 230V mains powered with sealed rechargeable lithium battery backup
• Interconnect with up to 23 compatible Kidde FIREX alarms
• Quick-Fit slide-on base for fast, tool-free fitting of the head
• Integrated cable management and 150mm flared base for neat retrofits
• Test/hush button to silence nuisance alarms
• Suitable for landlords, housing and new build installations

Technical Specifications

Frequently Asked Questions

Where should a smoke alarm be fitted?

Fit optical smoke alarms in hallways, landings and living areas. Use a heat alarm such as the Kidde KF31R in kitchens and garages where smoke or steam can cause false alarms.

Do I need to change the battery?

No. The KF21R uses a sealed rechargeable lithium cell that is charged by the mains supply, so there is no battery to replace.

How quickly will my order be dispatched?

This item is in stock and is usually dispatched within 1 working day. Orders over £40 ship free, and orders over 2kg go free Next Day.

What is the manufacturer part number?

This is the Kidde KF21R (EAN 0047871340238).