---
product_id: 531874932
title: "F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive Non-Toxic Compatible with Most Heating Systems Long-Lasting Seal"
brand: "kudos-trading"
price: "KD 20.18"
currency: KWD
in_stock: true
reviews_count: 13
category: "Kudos Trading"
url: https://www.desertcart.com.kw/products/531874932-f4-leak-sealer-500ml-liquid-seal-for-central-heating-pipe
store_origin: KW
region: Kuwait
---

# long-lasting leak protection 500ml ready-to-use liquid compatible with all pipe materials F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive Non-Toxic Compatible with Most Heating Systems Long-Lasting Seal

**Brand:** kudos-trading
**Price:** KD 20.18
**Availability:** ✅ In Stock

## Summary

> 💧 Seal leaks like a pro—because your heating system deserves the best!

## Quick Answers

- **What is this?** F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive Non-Toxic Compatible with Most Heating Systems Long-Lasting Seal by kudos-trading
- **How much does it cost?** KD 20.18 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.kw](https://www.desertcart.com.kw/products/531874932-f4-leak-sealer-500ml-liquid-seal-for-central-heating-pipe)

## Best For

- kudos-trading enthusiasts

## Why This Product

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

## Key Features

- • **Eco-Safe & Non-Toxic:** Non-corrosive, non-flammable, and environmentally friendly for worry-free use.
- • **Plug & Play Leak Fix:** Ready-to-use formula for instant application—no mixing, no fuss.
- • **Universal Compatibility:** Seals leaks in copper, brass, steel, plastic & more—one solution for all systems.
- • **Rapid System Circulation:** Quickly disperses through your heating system to seal hidden leaks fast.
- • **Blockage-Free Performance:** Unique formula prevents residue buildup, keeping your system efficient and smooth.

## Overview

F4 Leak Sealer is a 500ml polymer-based liquid designed for quick, effective sealing of small leaks in central heating and underfloor systems. Compatible with all common pipe materials, it offers long-lasting, non-toxic, and non-corrosive protection without causing blockages, ensuring optimal system performance and peace of mind.

## Description

Kudos-Trading - F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive Non-Toxic Compatible with Most Heating Systems Long-Lasting Seal : desertcart.co.uk: DIY & Tools

Review: Works well - Tried a cheaper make it stoppes a little bit, but was losing halve a pound pressure a week, drained the water filter on my Worcester oil boiler put 500ml in and maintained pressure 1 month now
Review: Stops those hard to find small leaks … - Over the years I’ve had a few of these and its worked for me stopping those annoying hard to fine leaks in the heating system. I always keep a spare one handy just in case the boiler starts to drop pressure regularly.

## Features

- Easy-to-use formula: Fernox F4 Leak Sealer is designed for quick and hassle-free application. It comes as a ready-to-use liquid that doesn't require any additional mixing or preparation, making it convenient for homeowners and professionals alike.
- Effective sealing performance: This high-quality leak sealer is engineered to efficiently and reliably seal small, inaccessible leaks and weeping joints in hydronic heating systems. Its advanced formulation ensures a long-lasting and dependable sealing effect on various materials, including metal, plastic, and composite pipes.
- Compatible with all metals and materials: The versatile Fernox F4 Leak Sealer is suitable for use in systems containing a wide range of materials, such as copper, brass, steel, iron, aluminium, and plastics. This makes it a perfect solution for diverse heating systems, regardless of their construction and components.
- Non-toxic and environmentally friendly: Developed with safety and sustainability in mind, Fernox F4 Leak Sealer is non-toxic, non-corrosive, and non-flammable. Its eco-friendly formulation means that it is safe for use in all domestic heating systems and poses no harm to the environment.
- Rapid dispersion and circulation: The liquid formulation of the Fernox F4 Leak Sealer allows for quick and even distribution throughout the system, ensuring that the product reaches all areas where leaks may be present. This rapid circulation ensures effective sealing and minimal downtime for your heating system.
- Effective in both open and closed systems: Whether your heating system is an open-vented or sealed system, the Fernox F4 Leak Sealer is designed to deliver optimal sealing performance. Its versatility makes it a go-to solution for a wide range of system types.
- Does not cause blockages or restrictions: Fernox F4 Leak Sealer's unique formulation prevents the formation of any solid residues, ensuring that it will not cause blockages or restrictions within the heating system. This means you can trust it to deliver excellent sealing without compromising the efficiency of your system.
- Long-lasting protection: With its superior sealing performance and compatibility with a wide range of materials, Fernox F4 Leak Sealer provides long-lasting protection against leaks and weeping joints. This helps extend the lifespan of your heating system and minimize the need for costly repairs.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0C4Q4KJ2S |
| Batteries Required? | No |
| Batteries included? | No |
| Best Sellers Rank | 11,329 in DIY & Tools ( See Top 100 in DIY & Tools ) 249 in Sealers |
| Colour | White |
| Customer Reviews | 4.4 4.4 out of 5 stars (79) |
| Date First Available | 9 May 2023 |
| Item Package Quantity | 1 |
| Item Weight | 500 g |
| Item model number | FER-56603 |
| Manufacturer | Kudos Trading |
| Material | Polymer-based |
| Part number | FER-56603 |
| Product Dimensions | 18.2 x 8.8 x 5 cm; 500 g |
| Style | Brass,Work |

## Product Details

- **Brand:** Kudos-Trading
- **Item dimensions L x W x H:** 18.2 x 8.8 x 5 centimetres
- **Item weight:** 500 Grams
- **Material:** Polymer-based
- **Style:** Brass,Work

## Images

![F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive Non-Toxic Compatible with Most Heating Systems Long-Lasting Seal - Image 1](https://m.media-amazon.com/images/I/61Op0ICOl1L.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works well
*by T***Y on 23 September 2025*

Tried a cheaper make it stoppes a little bit, but was losing halve a pound pressure a week, drained the water filter on my Worcester oil boiler put 500ml in and maintained pressure 1 month now

### ⭐⭐⭐⭐⭐ Stops those hard to find small leaks …
*by M***A on 6 September 2025*

Over the years I’ve had a few of these and its worked for me stopping those annoying hard to fine leaks in the heating system. I always keep a spare one handy just in case the boiler starts to drop pressure regularly.

### ⭐⭐⭐⭐ Does what i says on the plastic bottle but not for as long as I would want
*by G***E on 25 January 2025*

Definitely stops leaks but only seems to last for 8 to 12 months. So, a new application is required annually - not a big problem, as it’s probably as good as it gets regarding leak prevention in a radiator system.

## Frequently Bought Together

- Fernox F4 Leak Sealer 500ml Liquid Seal for Central Heating Pipe Work Leaks Water Underfloor Heating Non-Corrosive, Non-Toxic, Compatible with Most Heating Systems, Easy to Use, Long-Lasting Seal.
- Just Dose It Central Heating Dosing Tool, Radiator Dosing Funnel - For Adding Chemicals Like Fernox Central Heating Inhibitor, Sludge Remover, Leak Sealer & Sentinel X100
- Fernox 56599 F1 500 ml Central Heating Protector

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---

*Product available on Desertcart Kuwait*
*Store origin: KW*
*Last updated: 2026-03-01*