SKU: 67584308352

Kidde Sentry 5x KF21R Optical Smoke & 1x KF31R Heat Alarm Kit Mains Powered with Sealed-In Rechargeable Battery Back-Up c/w Quick Fit Base

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Description

Kidde Sentry 5x KF21R Optical Smoke & 1x KF31R Heat Alarm Kit Mains Powered with Sealed-In Rechargeable Battery Back-Up c/w Quick Fit BaseKidde Sentry 5x KF21R Optical Smoke & KF31R Heat Alarm Kit with Rechargeable Lithium Battery Back Up The Kidde Sentry Alarm Kit includes five KF21R Optical Smoke Alarms and one KF31R Heat Alarm, providing a complete fire detection solution for larger homes and multi storey residential properties. Designed for mains powered installation, each alarm features a sealed rechargeable lithium battery back up and can be interconnected with up to 23 compatible

Kidde Sentry 5x KF21R Optical Smoke & KF31R Heat Alarm Kit with Rechargeable Lithium Battery Back-Up

The Kidde Sentry Alarm Kit includes five KF21R Optical Smoke Alarms and one KF31R Heat Alarm, providing a complete fire detection solution for larger homes and multi-storey residential properties. Designed for mains-powered installation, each alarm features a sealed rechargeable lithium battery back-up and can be interconnected with up to 23 compatible Kidde FIREX alarms.

When one alarm detects danger, all connected alarms sound simultaneously, helping to provide early warning throughout the property. This makes the system ideal for improving fire safety across multiple rooms, floors and escape routes.

Each alarm is supplied with Kidde’s Quick-Fit Slide-On Base for fast installation and includes integrated cable management to keep wiring tidy and secure. The 150mm flared base plate also provides a clean retrofit finish when replacing existing alarms.

Kit Contents

  • 5 x Kidde KF21R Optical Smoke Alarms
  • 1 x Kidde KF31R Heat Alarm

KF21R Optical Smoke Alarm Features

The Kidde KF21R optical smoke alarm is designed to detect slow, smouldering fires caused by electrical faults, furniture or cigarettes. Ideal for hallways, bedrooms, lofts and living areas, the optical sensor provides reliable early warning protection.

  • Mains-powered optical smoke alarm with sealed rechargeable lithium battery back-up
  • Optical sensor with dust compensation and bug screen
  • Interconnects with up to 23 Kidde FIREX alarms
  • Alarm memory identifies the activated alarm
  • Combined Test/Hush button
  • Auto reset after activation
  • Tamper-resistant locking mechanism
  • Suitable for hallways, bedrooms, lofts and living rooms
  • BSI certified to BS EN14604:2005
  • 10-year warranty

KF31R Heat Alarm Features

The Kidde KF31R heat alarm is designed for kitchens, garages and loft spaces where smoke alarms may be unsuitable due to steam, cooking fumes or dust. The thermistor heat sensor provides dependable heat detection while helping minimise nuisance alarms.

  • Mains-powered heat alarm with sealed rechargeable lithium battery back-up
  • Thermistor heat sensor for reliable heat detection
  • Interconnects with up to 23 Kidde FIREX alarms
  • Alarm memory identifies the activated alarm
  • Combined Test/Hush button
  • Auto reset after activation
  • Tamper-resistant locking mechanism
  • Ideal for kitchens, garages and loft spaces
  • BSI certified to BS 5446 Part 2:2003
  • 10-year warranty including battery

Key Benefits

  • Complete smoke and heat alarm solution for larger residential properties
  • Sealed rechargeable lithium battery back-up for maintenance-free operation
  • Interlinked alarms provide whole-home warning when danger is detected
  • Quick-Fit bases for fast and efficient installation
  • Integrated cable management for organised wiring
  • Suitable for compliance with UK Building Regulations
  • Grade D1 domestic fire alarm system solution
  • Fully compatible with Kidde FIREX smoke, heat and CO alarms

Technical Specifications

KF21R Optical Smoke Alarm

  • Model: KF21R
  • Power Supply: 230V mains with sealed rechargeable lithium battery back-up
  • Sensor Type: Optical
  • Alarm Volume: 85dB minimum at 3 metres
  • Dimensions: 150mm x 150mm x 53mm
  • Weight: 260g
  • Operating Temperature: -10°C to +40°C
  • Warranty: 10 Years

KF31R Heat Alarm

  • Model: KF31R
  • Power Supply: 230V mains with sealed rechargeable lithium battery back-up
  • Sensor Type: Thermistor heat sensor
  • Alarm Volume: 85dB minimum at 3 metres
  • Dimensions: 150mm x 66mm
  • Weight: 245g
  • Operating Temperature: -10°C to +40°C
  • Warranty: 10 Years including battery

Please Note: Alarms are supplied individually within the kit. Installation should be completed by a qualified electrician.

Downloads

KF21R Data Sheet:
Download KF21R Data Sheet

KF31R Data Sheet:
Download KF31R Data Sheet

KF21R Instruction Manual:
Download KF21R Instruction Manual

KF31R Instruction Manual:
Download KF31R Instruction Manual

Shipping Notes
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Exchange/Return Notes
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SKU: 67584308352

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Gabrielle Grim
Waukegan, US
★★★★★ 5
Excellent product for dry mouth
Scent Name: Berry, Size: 100 Count
If you are having trouble with dry mouth, especially while sleeping, this is definitely the product for you. I have severe dry mouth and have tried multiple things including hard candy (yes, I know not very smart) as well as different biotin products, the mouthwash, the spray and the gel, which all do work, but do not last for very long. These stay in place open the corner of your mouth, last for hours and truly work. I highly recommend it if you are having a dry mouth issue
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Reviewed in the United States on February 5, 2026
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Sharon
Cuba, US
★★★★★ 5
Works great
Scent Name: Berry, Size: 100 Count
I have to use these for about 1/2 a year. I keep bronchitis and sinusitis from about Oct. to April every since I was a child. When I am suffering with these I can't breath through my nose, epically at night while sleeping and would wake up several times a night with dry mouth so bad ir was literally painful. My mom turned me on to these because she was using the with her CPAP. I sometimes have a bit of difficulty getting them to stay put but overall they are great. I have tried the OG, cinnamon, and berry. The OG have no real taste, but you wake up with a sweet taste in your mouth. I tried the cinnamon because I love cinnamon and didn't listen to the reviews stating how strong the flavor is, big regret, it's like putting two or three fireballs in your mouth, won't be making that mistake again. The berry ones are actually best in my opinion. They have a light berry flavor that isn't overpowering, isn't quite as sweet as the OG. Whichever one you choose you won't wake up in pain. I do suggest using only one at first as opposed to the two they recommend, unless you like waking up with your head on a water logged pillow. One generally gets me through the night unless my congestion is super bad, then I will sometimes have to use a 2nd one about 1/2 way through my night when I wake up for the bathroom and realize it's already completely dissolved.
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Reviewed in the United States on September 21, 2025
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KT
Battle Creek, US
★★★★★ 5
Get traction in your life work
Format: Paperback
This book is the best book I've read this year, giving concrete ideas on how to get more, I do mean more, in your life. Whatever your passion, be it starting a business, or in his case businesses, hobbies, relationships. One exercise Koch suggests is coming up with a list of your 10 best friends and rate them 1-10 (that in itself was fascinating) then put a percentage next to each friend. Are you spending the right amount of time with your closest, or more time with those less dear to you? His many insights will lead you in new ways to think about your life, your business, your family and friends. If you want to find new ways to think about your life, if you are in a rut and can't figure out what to do, if you are like me always busy and sometimes wondering am I doing the right things--this is a book for you. Richard Koch has written on this subject before and this is the best book for the individual.
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Reviewed in the United States on February 21, 2011
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Amazon Customer
Omaha, US
★★★★★ 5
Great Book
Format: Kindle
Excellent points to consider in leadership. The 80/20 principle is a great read for leaders everywhere. I liked the book.
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Reviewed in the United States on November 20, 2012
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Matt Bailey
Louisville, US
★★★★★ 4
Interesting Follow Up to the 80/20 Principle
Format: Paperback
If you enjoyed the 80/20 Principle this is a good guide to applying it in your life. He does make some bold predictions like highly competent individuals will soon make public corporations obsolete. Some of this book is highly speculative and other parts are very practical. Luckily it is pretty easy to tell which is which. Very interesting book.
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Reviewed in the United States on July 14, 2012

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