Kidde Firex Sentry Mains Powered Heat Alarm with 9V Backup Battery (KF31)

The Kidde KF31 (Firex Sentry series) is a mains-powered Grade D2 heat alarm featuring a 9V alkaline battery backup, engineered to provide reliable thermal detection in environments where optical smoke alarms are prone to false triggering.

Certified to BS 5446 Part 2:2003, the unit utilises an advanced thermistor sensor to respond rapidly to dangerous temperature rises, making it the ideal fire safety solution for kitchens, garages, utility rooms, and lofts exposed to dust, steam, or cooking fumes.

Designed for fast installation and clean retrofitting, the KF31 includes a Quick-Fit slide-on mounting base with integrated cable management and a 150mm flared base plate to conceal ceiling marks left by older units. The alarm supports hardwired interlinking with up to 24 compatible Kidde and Firex smoke, heat, and carbon monoxide alarms across a single network.

Routine maintenance and event diagnostics are streamlined via a combined Test/Hush button, backed by an automatic reset and an alarm memory function that pinpoints the initiating unit following an activation. Complete with a tamper-resistant base locking mechanism and mini-trunking knockouts, the unit features an 85dB sounder at 3 metres and is covered by a 10-year manufacturer warranty.