SKU: 49395378060

Kidde Sentry 4x KF21 Optical Smoke & 1x KF31 Heat Alarm Kit Mains Powered with 9V Alkaline Battery Back-Up c/w Quick Fit Base

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Description

Kidde Sentry 4x KF21 Optical Smoke & 1x KF31 Heat Alarm Kit Mains Powered with 9V Alkaline Battery Back-Up c/w Quick Fit BaseKidde Sentry 4x KF21 Optical Smoke & 1x KF31 Heat Alarm Kit with 9V Battery Back Up The Kidde Sentry Alarm Kit includes four KF21 Optical Smoke Alarms and one KF31 Heat Alarm, providing a complete mains powered fire detection solution for larger residential properties. Designed to deliver reliable smoke and heat detection throughout the home, each alarm features a 9V alkaline battery back up and can be interconnected with up to 23 compatible Kidde

Kidde Sentry 4x KF21 Optical Smoke & 1x KF31 Heat Alarm Kit with 9V Battery Back-Up

The Kidde Sentry Alarm Kit includes four KF21 Optical Smoke Alarms and one KF31 Heat Alarm, providing a complete mains-powered fire detection solution for larger residential properties. Designed to deliver reliable smoke and heat detection throughout the home, each alarm features a 9V alkaline battery back-up and can be interconnected with up to 23 compatible Kidde FIREX alarms.

This interlinked alarm system ensures that when one alarm detects danger, all connected alarms sound simultaneously, helping to provide earlier warning and improved occupant safety across multiple rooms and floors.

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

Kit Contents

  • 4 x Kidde KF21 Optical Smoke Alarms
  • 1 x Kidde KF31 Heat Alarm

KF21 Optical Smoke Alarm Features

The Kidde KF21 optical smoke alarm is ideal for detecting slow, smouldering fires caused by electrical faults, furniture or cigarettes. Suitable for escape routes and living spaces, the optical sensor provides dependable early warning protection.

  • Mains-powered optical smoke alarm with 9V alkaline 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 areas
  • BSI certified to BS EN14604:2005
  • 10-year warranty

KF31 Heat Alarm Features

The Kidde KF31 heat alarm is designed for kitchens, garages and loft spaces where smoke alarms may be unsuitable due to steam, dust or cooking fumes. Its thermistor heat sensor provides reliable temperature detection while helping reduce nuisance alarms.

  • Mains-powered heat alarm with 9V alkaline battery back-up
  • Thermistor heat sensor for dependable 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

Key Benefits

  • Complete smoke and heat alarm solution for larger homes
  • Interlinked alarms provide whole-home warning when danger is detected
  • Quick-Fit bases for fast and efficient installation
  • Integrated cable management for tidy wiring
  • Suitable for compliance with UK Building Regulations
  • Grade D domestic fire alarm system solution
  • Fully compatible with Kidde FIREX smoke, heat and CO alarms

Technical Specifications

KF21 Optical Smoke Alarm

  • Model: KF21
  • Power Supply: 230V mains with 9V alkaline battery back-up
  • Sensor Type: Optical
  • Alarm Volume: 85dB minimum at 3 metres
  • Dimensions: 150mm x 53mm
  • Weight: 295g
  • Operating Temperature: -10°C to +40°C
  • Warranty: 10 Years

KF31 Heat Alarm

  • Model: KF31
  • Power Supply: 230V mains with 9V alkaline battery back-up
  • Sensor Type: Thermistor heat sensor
  • Alarm Volume: 85dB minimum at 3 metres
  • Dimensions: 150mm x 150mm x 66mm
  • Weight: 281g
  • Operating Temperature: -10°C to +40°C
  • Warranty: 10 Years

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

Downloads

KF21 Data Sheet:
Download KF21 Data Sheet

KF31 Data Sheet:
Download KF31 Data Sheet

KF21 Instruction Manual:
Download KF21 Instruction Manual

KF31 Instruction Manual:
Download KF31 Instruction Manual

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 49395378060

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Lucio Lemus
Fort Morgan, US
★★★★★ 5
This is it
For the longest time I’ve STRUGGLED with finding a mount the works in my Tacoma. I don’t do off reading but every mount I use just can’t hang!! I got this and immediately impressed with the build quality. It’s entirely metal and can tell it’s sturdy. It took me 1 minute to install and the give you the one tool you need to install. I have an iPhone 13 Pro Max that baby isn’t going anywhere. You can adjust it with out unscrewing anything and it stays put. If you have a Tacoma stop wasting money on cheap mounts this is the last one you need I promise you
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 29, 2024
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Verified Purchase
Suraj
Whiting, US
★★★★★ 5
The only phone mount for a taco
This is a really quality product. So quality that I wish they made this for some of my other cars, I don't ever wanna use another phone holder. I was a bit skeptical on the longevity of the spring that holds it open, but a few months later and it feels just as sturdy as new. Fit is immaculate, the phone stays put. Worth the price. You will see when you see the machine finish on this product.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 25, 2025
K
Verified Purchase
Keith M
Los Angeles, US
★★★★★ 5
Fantastic Mount especially on rough Roads
Robust and discretely positioned mount. This mount is the real deal. It is by far the highest quality most stable mount that I've ever had in my Tacoma pickup. I also really like that it's positioned closer to the steering wheel in instead of in the windshield, making it easier to view. Very highly recommended!!
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Reviewed in the United States on January 27, 2026
R
Verified Purchase
Rosati
Chelsea, US
★★★★★ 5
Perfecto Product!!
I rarely write reviews, however on this product I need too. This clearly is a pricey phone mount, but after reading so many reviews I went for it & purchased. After opening, I immediately could see & feel the quality of material used. Installation was surprisingly easy & quick to my Tacoma. The mount is very firm, sturdy, very adjustable, perfectly designed product. For as costly as this was, I have absolutely no regrets! Totally can recommend this product to anyone with a Tacoma within the stated production years. So as so many others have said accurately in reviews, I am beyond satisfied even with the cost in mind.
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Reviewed in the United States on June 8, 2023
R
Verified Purchase
Ren Bolln
Omaha, US
★★★★★ 5
Perfect fit for my 2018 sr5 Tacoma. Great quality!
Extremely well made. Doesn't rattle or slide off. Holds the phone tightly. Finally found a phone mount that works great for my Tacoma (2018 sr5). I highly recommend this product.
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Reviewed in the United States on December 5, 2025

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