---
product_id: 50590449
title: "Twin Pack Kidde Firex KF20 Mains Powered Optical Smoke Alarm with 9V Back Up Batteries | KF2 | 4973"
brand: "kidde"
price: "€ 110.34"
currency: EUR
in_stock: true
reviews_count: 11
category: "Kidde"
url: https://www.desertcart.com.cy/products/50590449-twin-pack-kidde-firex-kf20-mains-powered-optical-smoke-alarm
store_origin: CY
region: Cyprus
---

# Mains-powered with low energy use 9V battery backup included Interlink up to 23 alarms Twin Pack Kidde Firex KF20 Mains Powered Optical Smoke Alarm with 9V Back Up Batteries | KF2 | 4973

**Brand:** kidde
**Price:** € 110.34
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with Kidde’s smart, interconnected smoke alarms 🔗

## Quick Answers

- **What is this?** Twin Pack Kidde Firex KF20 Mains Powered Optical Smoke Alarm with 9V Back Up Batteries | KF2 | 4973 by kidde
- **How much does it cost?** € 110.34 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.cy](https://www.desertcart.com.cy/products/50590449-twin-pack-kidde-firex-kf20-mains-powered-optical-smoke-alarm)

## 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

- • **Energy Smart Design:** Reduced energy consumption means lower lifetime running costs
- • **Reliable Power Backup:** 9V alkaline batteries keep you safe even during outages
- • **Tamper-Proof Security:** Locking device prevents unauthorized removal, ensuring continuous protection
- • **User-Friendly Control:** Combined Test/Hush™ button for easy testing and nuisance alarm silencing
- • **Seamless Safety Network:** Interconnect up to 23 Kidde alarms for whole-home protection

## Overview

The Kidde Firex KF20 is a mains-powered optical smoke alarm with 9V battery backup, designed to interlink with up to 23 other Kidde alarms for comprehensive home safety. Featuring energy-efficient operation, a combined test/hush button, tamper-resistant locking, and dust/bug screens to reduce false alarms, it meets UK Building Regulations and comes with a 6-year warranty for trusted, long-term protection.

## Description

Mains-powered optical smoke alarm that can be interlinked with up to 23 other Kidde mains alarms, be they ionisation, optical or heat. Once interlinked, the detection of the relevant danger by an individual unit will sound across all the connected alarms. Optical alarms are for use in escape or circulation routes and in areas where there is a danger of ignition of furniture and surroundings by cigarettes producing slow, smouldering fires. This mains-powered unit should be installed by a qualified electrician and can be used throughout the home, except in the kitchen where a Firex Heat Alarm is recommended. These alarms comply with UK Building Regulations for new housing and associated standards (Grade D BS 5839, Part 6).

Review: Great replacement for older models - Perfect replacement for 20 year old Firex FADC230 smoke alarms that should have been replaced 10 years ago. They fitted the existing base plate and wiring although these are included with the pack. Wish I had done this earlier, but thought I needed an electrician as ours are interconnected but no need, replaced in a matter of minutes. Photos show old onesthat were replaced for reference.
Review: Delivery promise by desertcart on Prime not achieved. - desertcart Prime failed to deliver until late. Tracking for a delayed product leaves you in limbo. Not knowing when it will arrive. However, the product is excellent and compatible with earlier sensors. No problem with installation.

## Features

- Mains-powered optical smoke alarm that can be interlinked with up to 23 other Kidde mains alarms, be they ionisation, optical or heat. Once interlinked, the detection of the relevant danger by an individual unit will sound across all the connected alarms.
- Interlink with up to 23 Kidde Firex hard-wired alarms – all alarms sound if danger is detected
- Mains operation – 9V Alkaline back-up battery supplied as standard
- Reduced energy consumption – lower lifetime running costs (* compared to previous Firex alarms)
- Combined Test/HushTM button allows regular testing of alarm function and can be used to temporarily silence nuisance alarms
- Dust compensation and bug screen – reduces nuisance alarms
- Alarm memory – identifies source unit within interconnecting network
- Auto reset after activation
- Tamper-resistant locking device prevents unauthorised removal without the use of a tool
- Warranty 6 years, BSI certified to BS EN14604:2005 and CE tested and certified to 0086-CPD-535595 15 EN14604:2005

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00LGX1TSC |
| Batteries | 2 9V batteries required. (included) |
| Batteries Required? | No |
| Batteries included? | Yes |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | 2,598 in DIY & Tools ( See Top 100 in DIY & Tools ) 21 in Smoke Alarms |
| Colour | White |
| Customer Reviews | 4.6 4.6 out of 5 stars (865) |
| Date First Available | 2 July 2014 |
| Delivery information | We cannot deliver certain products outside mainland UK ( Details ). We will only be able to confirm if this product can be delivered to your chosen address when you enter your delivery address at checkout. |
| Item Package Quantity | 1 |
| Item Weight | 500 g |
| Item model number | KF2 4973 |
| Package Dimensions | 16.4 x 16 x 11.7 cm; 500 g |
| Part Number | KF2 4973 |
| Power Source | Battery Powered |
| Style | Classic |
| Voltage | 240 Volts |

## Product Details

- **Alarm:** Audible
- **Brand:** Kidde
- **Colour:** White
- **Item weight:** 500 Grams
- **Power source:** Battery Powered
- **Sensor type:** Photoelectric
- **Style:** Classic
- **UPC:** 799441946892

## Images

![Twin Pack Kidde Firex KF20 Mains Powered Optical Smoke Alarm with 9V Back Up Batteries | KF2 | 4973 - Image 1](https://m.media-amazon.com/images/I/31Xv-Q7FuUL.jpg)

## Questions & Answers

**Q: Will this alarm fit on to existing backing plate of a firex 1240c series alarm?**
A: I bought my Kidde alarms to replace existing alarms from a different manufacturer and new backing plates were supplied. However I realised that there was little difference between the backing plates so I just used the ones that were already there.  Given you are talking about a firex alarm, I'm sure you'd be ok but you might like to check the manufacturer's website to check.

**Q: Are you selling 2 x kf2 or 2 x kf20 ?**
A: The KF2 is discontinued and the newer version is the KF20. You will receive 2x KF20 alarms.

**Q: Are these same fittings for firex padc240 ?**
A: Yes they will replace the old Firex model

**Q: My alarms are slightly different but need replacing but my wires are different colours mine are blue white and brown is this a problem?**
A: All alarms now have a "Link" wire, they are used to couple up (or link) numbers of alarms together, so if one alarm sounds, all sound. That is what the white wire is used for. If you don't need or want to link alarms, just make safe the white wire with a connector and leave it disconnected. The brown is the permanent live, the Blue is the neutral, both have to be supplied from your mains electric circuit.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great replacement for older models
*by T***M on 6 September 2025*

Perfect replacement for 20 year old Firex FADC230 smoke alarms that should have been replaced 10 years ago. They fitted the existing base plate and wiring although these are included with the pack. Wish I had done this earlier, but thought I needed an electrician as ours are interconnected but no need, replaced in a matter of minutes. Photos show old onesthat were replaced for reference.

### ⭐⭐⭐⭐⭐ Delivery promise by Amazon on Prime not achieved.
*by S***D on 31 August 2025*

Amazon Prime failed to deliver until late. Tracking for a delayed product leaves you in limbo. Not knowing when it will arrive. However, the product is excellent and compatible with earlier sensors. No problem with installation.

### ⭐⭐⭐⭐ Easy to install, easy to use.
*by T***N on 8 July 2017*

very easy to swap in where my older 12yr old Kidde smoek alarms were. Very easy to fit, but one came with a dud battery - so be sure to check that before fitting. I didn't know smoke alarm detectors only had a 10yr lifespan, My old ones had started to go off at random a lot. It wasn't until I took them down that I saw the sticker on the back advising they be changed every 10years. Since I swapped these new ones in no such problem. The new ones clicked right into the same fitting that was still screwed to the ceiling.

## Frequently Bought Together

- Twin Pack Kidde Firex KF20 Mains Powered Optical Smoke Alarm with 9V Back Up Batteries | KF2 | 4973
- Kidde Firex KF20 Optical Smoke Alarm - Mains Operated with Battery Back Up
- Firex KF30 Kidde Firex Alarm, White

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.com.cy/products/50590449-twin-pack-kidde-firex-kf20-mains-powered-optical-smoke-alarm](https://www.desertcart.com.cy/products/50590449-twin-pack-kidde-firex-kf20-mains-powered-optical-smoke-alarm)

---

*Product available on Desertcart Cyprus*
*Store origin: CY*
*Last updated: 2026-02-03*