Kidde Firex Sentry Mains Powered Heat Alarm with Rechargeable Battery (KF31R)

The Kidde Firex Sentry KF31R is a 230V mains-powered heat alarm engineered specifically for high-risk, high-nuisance areas such as kitchens, boiler rooms, converted or unconverted lofts, and garages. Utilising a fast-acting thermistor heat sensor, it triggers upon sensing rapid temperature rises or ambient heat exceeding 57°C, avoiding the false alarms common to standard smoke detectors in steam- or fume-heavy environments.

Designed with installer efficiency in mind, the KF31R includes a Quick-Fit slide-on base with built-in cable management for rapid mounting without requiring a separate pattress. A flared 150mm base plate easily covers old fixture marks for a clean retrofit finish. Powered by 230V AC mains, it features a long-life sealed rechargeable lithium backup battery that delivers continuous protection during power outages and removes the need for regular battery replacements.

The unit can be hardwire interlinked with up to 23 other Kidde Firex mains-powered smoke, heat, or carbon monoxide alarms, triggering all interconnected units when heat is detected. A combined test/hush button allows for simple testing and temporary silencing, while an integrated alarm memory function quickly identifies the activating unit across the interlinked circuit. Certified to Grade D1 standards (BS 5446-2:2003), it offers dependable fire compliance for modern domestic installations.