SKU: 61658278347

Kidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Alkaline Battery Back-Up c/w Quick Fit Base

Sale price$19.24 Regular price$21.38
Save 10%

Pay in installments of $5.34 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 11 - Aug 16

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Kidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Alkaline Battery Back-Up c/w Quick Fit BaseKidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Battery Back Up The Kidde KF21 Sentry Optical Smoke Alarm is a reliable mains powered smoke detector designed to provide early warning of slow, smouldering fires within residential properties. Featuring an advanced optical sensor, the KF21 is ideal for hallways, landings, bedrooms, living areas and loft spaces, helping to improve fire safety throughout the home. This interconnectable smoke

Kidde KF21 Sentry Mains Powered Optical Smoke Alarm with 9V Battery Back-Up

The Kidde KF21 Sentry Optical Smoke Alarm is a reliable mains-powered smoke detector designed to provide early warning of slow, smouldering fires within residential properties. Featuring an advanced optical sensor, the KF21 is ideal for hallways, landings, bedrooms, living areas and loft spaces, helping to improve fire safety throughout the home.

This interconnectable smoke alarm can be linked with up to 23 compatible Kidde FIREX smoke, heat and carbon monoxide alarms, ensuring that when one alarm detects danger, all connected alarms sound simultaneously for maximum protection.

Designed with installers in mind, the KF21 includes a Quick-Fit Slide-On Base for fast and tidy installation, while the 150mm flared base plate neatly covers marks left by larger existing alarms during retrofit projects.

Key Features

  • Mains-powered optical smoke alarm with 9V alkaline battery back-up
  • Interconnects with up to 23 compatible Kidde FIREX alarms
  • Advanced optical sensor for detecting slow, smouldering fires
  • Quick-Fit Slide-On Base for rapid installation
  • 150mm flared base plate for clean retrofitting
  • Integrated cable management for secure and tidy wiring
  • Alarm memory identifies the triggered alarm within the network
  • Combined Test/Hush button for testing and silencing nuisance alarms
  • Auto reset following alarm activation
  • Tamper-resistant locking mechanism
  • Suitable for lofts, hallways, bedrooms and living rooms
  • Fully compatible with Kidde FIREX smoke, heat and CO alarms
  • 10-year manufacturer warranty

Ideal Applications

The Kidde KF21 optical smoke alarm is suitable for installation in:

  • Hallways and circulation routes
  • Bedrooms
  • Living rooms
  • Attics and loft spaces
  • Residential properties requiring Grade D2 fire detection

Optical smoke alarms are particularly effective at detecting slow-burning fires caused by upholstery, electrical faults or cigarettes, making them ideal for living spaces and escape routes.

Technical Specifications

  • Model: KF21
  • Power Supply: 230V mains with 9V alkaline battery back-up
  • Sensor Type: Optical with dust compensation and bug screen
  • Alarm Volume: Minimum 85dB at 3 metres
  • Alarm Frequency: 3.2 kHz typical
  • Interconnectivity: Up to 23 compatible alarms
  • Alarm Grade: D2
  • Approvals: BSI certified to BS EN14604:2005
  • Dimensions: 150mm x 53mm
  • Weight: 295g including battery
  • Operating Temperature: -10°C to +40°C
  • Humidity Range: Up to 93% RH non-condensing
  • Warranty: 10 Years

Compliance & Installation

The Kidde KF21 complies with UK Building Regulations and BS 5839 Part 6 requirements for Grade D domestic fire alarm systems. Installation should be carried out by a qualified electrician. For kitchen installations, a dedicated Kidde FIREX heat alarm is recommended instead of a smoke alarm.

Downloads

Data Sheet:
Download Data Sheet

Instruction Manual:
Download 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]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 61658278347

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.8 ★★★★★
Based on 23 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
T
Verified Purchase
the revJ
Natrona Heights, US
★★★★★ 5
Wow it's smooth, soft, not overly scented
Scent: Hair Styler (1 Pack)
I rarely try new hair products. I use Aveda sculpting clay and when I tell most stylists this they simply stop trying to sell me their sponsored hair product since they know how good Aveda is. I've never seen a product as smooth as this; it feels like hand lotion and goes in super easy and has a nice hold with really minimal residue. Feels great to put hand through hair after putting this in. This stuff is really different - I'm a fan!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 24, 2024
S
Verified Purchase
Stephen H. Gorman
Boise, US
★★★★★ 5
Huron
Scent: Hair Styler (1 Pack)
Great product
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 30, 2025
T
Verified Purchase
Timothy
Lexington, US
★★★★★ 3
Not bad but read my full review if you are experimenting with different brands
Scent: Hair Styler (1 Pack)
So I am middle of the road on this product. First, I love the products from this brand and use some of their other products quite regularly. I was on a search for an alternative to the Crew Forming Cream (which I have used for maybe 20 years) and decided to purchase this product by Huron as well as the much cheaper medium hold styling cream by Cremo. All three are great products but you will need to decide for yourself how much hold you need as I have discovered that each are quite different and really shouldn't be compared to one another. I will say that if I had to put them all into two categories then Crew is heavy hold and Huron and Cremo is medium / light hold. I must admit that I was skeptical that the cheaper of the three, Cremo, would win me over but it has. For the record it has a very subtle scent (hardly noticable), just enough hold and does not leave you feeling like you have product in your hair. This is similar to Huron as well (although Huron is a very creamy in texture and you can tell its a higher quality product) but at the end of the day all that matters is great hold from a product that is affordable and does not leave a sticky texture in your hair. Cremo wins hands down. As for Crew, well it was a good ride but too expensive and way too heavy...time to move on.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 1, 2025
C
Verified Purchase
coronad0
Boise, US
★★★★★ 5
So lightweight. Perfect for extra thick hair.
Scent: Hair Styler (1 Pack)
Its almost mousse like in how light weight it is and smells fantastic. I wanted something just above light weight hold and not weigh my thick hair down and this does a great job. A little pricey but SO much better than the usual store brands out there. And my wife is totally in love with how great it smells when I put it on, so bonus!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 22, 2024
J
Verified Purchase
Jason Kearns
Waukegan, US
★★★★★ 5
Smells good and doesn’t feel greasy
Scent: Hair Styler (1 Pack)
Product didn’t leave a greasy feeling to the hands or the hair. Kept hold all day for my hair style but I knew it was light hold going in. It has a great scent
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 15, 2024

recommand products