Vaillant 80/125mm Horizontal Flue Kit | 303209 | ecoTEC Compatible

Description

The Vaillant 80/125mm Horizontal Flue Kit is a complete concentric air/flue solution for compatible Vaillant ecoTEC boiler installations. Supplied with the horizontal terminal duct, 87° boiler elbow and wall rosettes, it provides a neat, reliable route for combustion air intake and safe dispersal of flue gases through an external wall.

Designed for professional installation, this 80/125mm flue system supports extended horizontal runs when used with approved Vaillant extensions and elbows. The room sealed concentric design helps maintain efficient boiler operation while keeping flue components protected and neatly finished inside and outside the property.

80/125mm

Concentric flue size

87°

Boiler elbow included

970mm

Terminal duct length

ecoTEC

Compatible flue system

303209

Vaillant part number

Complete

Horizontal flue kit

Installation information: The horizontal flue must be installed with the correct downward gradient back to the boiler to allow condensate management, in accordance with the boiler and flue installation instructions.

Compatibility note: This kit is intended for Vaillant 80/125mm concentric flue systems. Always confirm the required flue configuration, maximum permissible length and boiler connection details against the installation instructions for the specific appliance.

Safety and compliance: Flue installation must be carried out by a competent, suitably qualified installer in accordance with current UK building regulations, manufacturer instructions and applicable gas safety requirements.

Key Features

Complete Horizontal Flue Kit

Includes the horizontal terminal duct, 87° elbow, inner and outer rosettes for a coordinated wall through installation.

80/125mm Concentric Design

The concentric air/flue arrangement supplies combustion air and expels products of combustion through a single external wall penetration.

Vaillant ecoTEC Compatibility

Manufactured for use with compatible Vaillant ecoTEC boilers that specify an 80/125mm flue connection.

Extended Run Capability

Can form part of a longer horizontal flue run using approved Vaillant extensions, subject to the maximum length and elbow allowances stated in the appliance instructions.

Neat Internal and External Finish

Supplied rosettes help deliver a tidy finish where the flue passes through the wall, supporting a professional installation appearance.

Genuine Vaillant Component

A genuine Vaillant flue accessory, identified by part number 303209, designed to integrate with the manufacturer’s flue system.

Technical Specifications

Product Identification

Brand

Vaillant

Manufacturer part number (MPN)

303209

EAN / barcode

4024074343432

Product type

Horizontal concentric flue kit

Flue System

Flue diameter

80/125mm concentric

Flue orientation

Horizontal

Terminal duct length

970mm to face of outer wall

Included elbow

87° boiler elbow

Included rosettes

Inner and outer wall rosettes

Compatibility and Installation

Compatible system

Vaillant 80/125mm concentric flue systems

Typical application

Compatible Vaillant ecoTEC boiler installations

Installation gradient

Downward gradient back to the boiler, as specified by Vaillant

Installer requirement

Suitably qualified competent installer

Physical Details

Approximate weight

5.223kg

Finish

Standard white concentric flue finish

Frequently Asked Questions

What is included with this Vaillant 80/125mm horizontal flue kit?

The kit includes the horizontal terminal duct, 87° boiler elbow, inner rosette and outer rosette, providing the core components for a horizontal wall through flue installation.

Which boilers is this flue kit compatible with?

It is designed for Vaillant 80/125mm concentric flue systems and is commonly used with compatible Vaillant ecoTEC appliances. Always check the specific boiler’s installation instructions to confirm flue type, connection and maximum run length.

Can the flue run be extended?

Yes, the system can generally be extended using approved Vaillant 80/125mm flue extensions and elbows. The maximum permissible flue length is reduced by each additional elbow, so the final configuration must be calculated from the appliance manufacturer’s instructions.

Does the flue need to be installed at an angle?

Yes. The horizontal flue should be installed with the required downward gradient back towards the boiler to support correct condensate handling and comply with the installation instructions.

Who should install this flue kit?

Installation should be completed by a competent, suitably qualified heating engineer, following the boiler and flue manufacturer’s instructions along with current UK regulations and best practice.

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Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

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