---
product_id: 53089982
title: "Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up"
brand: "kidde"
price: "₨1176"
currency: SCR
in_stock: true
reviews_count: 8
category: "Kidde"
url: https://www.desertcart.sc/products/53089982-kidde-firex-kf20-optical-smoke-alarm-mains-operated-with-battery
store_origin: SC
region: Seychelles
---

# Photoelectric optical sensor Battery backup for power cuts Interlink up to 23 alarms Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up

**Brand:** kidde
**Price:** ₨1176
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with Kidde KF20 — safety that never sleeps! 🔥

## Quick Answers

- **What is this?** Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up by kidde
- **How much does it cost?** ₨1176 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sc](https://www.desertcart.sc/products/53089982-kidde-firex-kf20-optical-smoke-alarm-mains-operated-with-battery)

## Best For

- kidde enthusiasts

## Why This Product

- Trusted kidde brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Smart Smoke Detection:** Photoelectric sensor minimizes false alarms from steam or cooking
- • **User-Friendly Control:** Combined test/hush button for easy maintenance and peace of mind
- • **Tamper-Resistant Design:** Secure locking device keeps your safety system intact
- • **Uninterrupted Vigilance:** Mains powered with battery backup ensures 24/7 reliability
- • **Seamless Networked Safety:** Interlink up to 23 alarms for whole-home protection

## Overview

The Kidde Firex KF20 is a mains-operated optical smoke alarm with a battery backup, designed for reliable detection of slow smouldering fires. It supports interlinking up to 23 units, features a photoelectric sensor to reduce false alarms, and includes a tamper-resistant locking device. Certified to BSi Kitemark standards, it meets current building regulations and offers easy installation and maintenance for comprehensive home fire safety.

## Description

Product Description Kidde Firex smoke alarms offer the very best in quality and reliability. Certified to the highest BSi Kitemark standards and offering a wide range of alarms to suit most applications you can be assured that you are in safe hands. The KF20 is compliant with the latest in building regulations for new housing. The KF20 utilises photo-electric (optical) detection facility. They are best suited where there is a danger of slow smouldering fires such as those caused by cigarettes for example on foam filled furniture or bedding. They are less prone to nuisance alarms caused by steam or cooking particles. They can be disposed of with general household waste. Box Contains 1 x KF2, Battery & Instructions

Review: They work and are easy to install. - Firs,t you need to check the regulations for your area. These directly exchange for for the older models if you have them (screw into existing baseplate) but would also not be too difficult to fit as new items - again, though, check if you can do this or whether you need a registered electrician,
Review: Good quality - Well, I'd like to say it works perfectly. But I don't want it to go off unless theirs a fire haha. But seems absolutely fine. 😊 thanks

## Features

- Interlink with up to 23 Firex hard-wired alarms
- Combined test/hush button
- Auto reset
- Tamper-resistant locking device
- Mains operation
- The Kidde KF2 smoke alarm is a mains powered alarm contains battery in it as a backup in case of a power cut.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B006J56XQU |
| Alarm | Visual |
| Best Sellers Rank | 5,239 in DIY & Tools ( See Top 100 in DIY & Tools ) 30 in Smoke Alarms |
| Brand | Kidde |
| Colour | White |
| Country of Origin | China |
| Customer Reviews | 4.6 out of 5 stars 1,493 Reviews |
| Global Trade Identification Number | 00020967049737 |
| Item Type Name | Mains Optical Smoke Alarm |
| Item Weight | 280 Grams |
| Item weight | 280 Grams |
| Manufacturer | Kidde |
| Model Number | KF2 |
| Power source | Battery Powered |
| Product Style | Back Up |
| Sensor Type | Photoelectric |
| Style | Back Up |
| UPC | 020967049737 |
| Unit Count | 1.0 count |

## Product Details

- **Alarm:** Visual
- **Brand:** Kidde
- **Colour:** White
- **Global Trade Identification Number:** 00020967049737
- **Item weight:** 280 Grams
- **Manufacturer:** Kidde
- **Power source:** Battery Powered
- **Sensor type:** Photoelectric
- **Style:** Back Up
- **UPC:** 020967049737

## Images

![Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up - Image 1](https://m.media-amazon.com/images/I/515CCoZk4qL.jpg)

## Questions & Answers

**Q: Title says mains alarm. Does this actually work off the 240v mains domestic supply. There is nothing in the description that mentions transformer, ect**
A: The product voltage is 230, it works perfectly well off 240 volt with no need for a transformer as you mention.

**Q: Hi. The title of the listing says the smoke alarm is the optical kind. The listing's description says it is the ionisation kind. What is the product?**
A: The KF2 (which for your information is now the KF20 which is supplied) is an optical smoke alarm.I will amend the listing description.

**Q: Does this alarm come with a plug?**
A: It comes with a connection plug to connect the direct mains supply to the alarm.

**Q: Does it fit the plates of Deta 1111 model?**
A: No, you will need to change the mounting/base plate which is supplied with the alarm.

## Customer Reviews

### ⭐⭐⭐⭐⭐ They work and are easy to install.
*by U***K on 28 January 2026*

Firs,t you need to check the regulations for your area. These directly exchange for for the older models if you have them (screw into existing baseplate) but would also not be too difficult to fit as new items - again, though, check if you can do this or whether you need a registered electrician,

### ⭐⭐⭐⭐⭐ Good quality
*by I***N on 18 November 2025*

Well, I'd like to say it works perfectly. But I don't want it to go off unless theirs a fire haha. But seems absolutely fine. 😊 thanks

### ⭐⭐⭐⭐⭐ KF20 is a very easy to install replacement for old Firex 4973 due to matching base plate and plug
*by J***C on 14 June 2024*

I did my research so I could use the base plate and electric plug of the old one (a Firex 4973) and avoid the cost of an electrician and still be safe to DIY this job. The KF20 is that kind of simple to install replacement. I only needed ladder, a flathead screwdriver to push the little button in and turn the whole front cover anti-clockwise. Then I just gently (with a little nudge under the clip ) the plug off and voila... ready to receive the new one. The new one had a long yellow strip of plastic over the enclosed battery that needed to be removed when installing to get the battery to operate, but confusingly on the strip in small lettering it stated "permanently connect ac power before removing - which is impossible to do as the battery cover is held down by the plug when it is inserted. So I did a quick call to their technical department and the gentleman said "no go ahead remove it before installing the plug bit. No problem but we only write this on there because sometimes people remove this plastic strip and then wait weeks before installing the whole thing and without it being plugged into the mains the battery drains whilst it is laying around. Ok, once I knew that I pulled the strip, heard the loud beep of contact, sign the battery is working . Then got on the ladder attached the 3 pin plug, folded the wiring neatly and twisted clockwise the cover onto the base, nice little click ... And all done and dusted. I have gone and ordered a new one for upstairs too ( that was a ionised one, but they have been phased out ), but I checked and base plate for that one (he said on the phone) fits as well with this model too and so does the plug. Lets hope that one goes as smooth as this one : less that 10 minutes, including the call. Even a 59 yr old woman can do this installation, lol! Love how this brand keeps it simple and really customer friendly with same base plate and plugs.... some mobile phone companies could learn a thing of 2 from these guys : )

## Frequently Bought Together

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*Product available on Desertcart Seychelles*
*Store origin: SC*
*Last updated: 2026-03-11*