---
product_id: 49932989
title: "Kidde Firex KF3 ( Mains/Battery Heat alarm )"
brand: "kidde"
price: "$U4785"
currency: UYU
in_stock: true
url: https://www.desertcart.uy/products/49932989-kidde-firex-kf3-mains-battery-heat-alarm
store_origin: UY
region: Uruguay
---

# BSI certified safety Compact 133mm design 230V mains + 9V backup Kidde Firex KF3 ( Mains/Battery Heat alarm )

**Brand:** kidde
**Price:** $U4785
**Availability:** ✅ In Stock

## Summary

> 🔥 Safety Meets Style: Your Home's Silent Guardian! 🔒

## Quick Answers

- **What is this?** Kidde Firex KF3 ( Mains/Battery Heat alarm ) by kidde
- **How much does it cost?** $U4785 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.uy](https://www.desertcart.uy/products/49932989-kidde-firex-kf3-mains-battery-heat-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

- • **Test with Ease:** Combined Test/Hush™ button for hassle-free maintenance.
- • **Compact & Sleek:** Designed to fit seamlessly into any home decor.
- • **Certified Protection:** BSI certified for your peace of mind.
- • **Stay Safe, Stay Smart:** With a dual power supply, never worry about safety.
- • **Long-lasting Assurance:** Enjoy a 6-year warranty for ultimate reliability.

## Overview

The Kidde Firex KF3 is a state-of-the-art heat alarm that combines mains power with a 9V alkaline battery backup, ensuring your home remains protected at all times. With a compact design and BSI certification, this alarm not only looks good but also meets the highest safety standards. The innovative Test/Hush™ button allows for easy testing and silencing of nuisance alarms, making it a must-have for any modern home. Plus, with a 6-year warranty, you can trust in its long-lasting performance.

## Description

Kidde Firex KF3 ( Mains/Battery Heat alarm )

## Features

- Power Supply 230V mains-powered with 9V Alkaline battery back-up
- Alarm Dimensions - 133 x 133 x 6mm. Bracket Dimensions - 127 x 127 x 39mm. (213g)
- Combined Test/HushTM button allows regular testing of alarm function and can be used to temporarily silence nuisance alarms
- Approvals - BSI certified to BS5446 Part 2: 2003. CE tested and certified
- Warranty - 6 years

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Part Number | STE04027 |
| Package Dimensions | 13.72 x 13.72 x 6.86 cm; 240 g |
| Batteries | 1 9V batteries required. (included) |
| Item model number | 4899 |
| Colour | White |
| Style | Classic |
| Power Source | Battery Powered |
| Item Package Quantity | 1 |
| Batteries included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Alkaline |
| Item Weight | 240 g |

## Product Details

- **Brand:** Kidde
- **Style:** Classic
- **Power source:** Battery Powered
- **Colour:** White
- **Item weight:** 0.24 Kilograms
- **Alarm:** Visual
- **Sensor type:** ionisation,optical
- **UPC:** 020967048990

## Images

![Kidde Firex KF3 ( Mains/Battery Heat alarm ) - Image 1](https://m.media-amazon.com/images/I/51Z5bcJ45QL.jpg)

## Questions & Answers

**Q: Can I use it with just the battery?**
A: No, it has to be mains connected and the battery is a back-up in case it loses the electricity mains supply.

**Q: I have three kf3 alarms, have these now been replaced with the kf30. thanks**
A: I'm not sure but my old one was approx. 16 yr old. I purchased the one that looked the same as mine and it fit without needing to change any wiring. All the fittings were exactly the same.

**Q: I have a120-1022f what unit will be  a straight swap.**
A: This is a very old part number. If this is a Firex heat alarm then the KF30 will be the current replacement as all Firex models are compatible with previous versions. However, the wiring loom and mounting plate will need to be replaced (these are included with the alarm).

**Q: Can I replace the 1240c with the kf3?**
A: The KF3 is a heat alarm - Kidde Firex I240C Mains / Battery Back Up Smoke Alarm -Ionisation (New model KF1)

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*Product available on Desertcart Uruguay*
*Store origin: UY*
*Last updated: 2026-02-05*