Mains Powered Optical Smoke Alarm with Back-Up Battery - Kidde Firex Sentry KF21
The Kidde Firex KF21 and KF21R are 230V mains‑powered optical smoke alarms engineered for dependable, energy‑efficient fire detection. Designed for whole‑property protection, they can be hard‑wired and interlinked with up to 24 compatible units. The KF21 is supplied with a replaceable alkaline back‑up battery, while the KF21R features a long‑life rechargeable lithium back‑up that lasts for the full lifespan of the alarm.
- 230V optical smoke alarm for hallways, landings, and living areas
- Alkaline or lithium back‑up options to suit installation requirements
- 10 year warranty for long‑term reassurance
- Hard‑wire interlinking with up to 24 compatible units
- Kitemarked to
- Suitable for Grade D1 (KF21R) or Grade D2 (KF21) installations
- UKCA and CE marked
- Test / Hush button for routine testing and false‑alarm control
- Tamper-resistant locking to prevent unauthorised removal
- Supplied with dust cover for temporary protection during building work
- Includes fixings (2 x screws and 2 x rawl plugs)
- This alarm is also suitable for both the Welsh and Scottish updated 2022 legislation
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Review this product nowTechnical Data
| Product Code | KEKF21 |
|---|---|
| Brand | Kidde |
| Approvals & Markings | CE Marked |
| UKCA Marked | |
| Back-Up Battery Type | Alkaline |
| Battery Type | 9V Battery |
| British Standard Grade | Grade D2: Mains Powered (replaceable backup) |
| Colour | White |
| Compliance | BS 5839-6 |
| BS EN14604:2005+AC:2008 | |
| Connection | Wired |
| Display | LED Indicators |
| Fixing Options | Screws (included) |
| Installation Position | Ceiling |
| Wall | |
| Material | Plastic |
| Maximum Number of Linked Devices | 24 Devices |
| Operating Temperature | -10°C To +40°C |
| Positioning | Bedrooms |
| Hallways | |
| Living Rooms | |
| Power Type | Mains Powered (230V) |
| Recyclable | Yes - Valpak's WEEE Distributor Take-back Scheme |
| Relative Humidity | Up To 93% |
| Sensor Type | Optical |
| Sound Level | 85dB |
| Suitability | Home |
| Warning Type | Audible - Alarm Sounder |
| Warranty | 10 Years |
| Dimensions (Unit) |
|
| Weight | 295g |
| Datasheets |