Product Description

100mm to 125mm Black Stove Pipe Increaser – VIT-Smooth

Model: 67-100-002

The VIT-Smooth 100mm to 125mm black stove pipe increaser connects a 100mm flue pipe to a 125mm flue pipe. Also known as a 4-inch to 5-inch flue adaptor, it increases the flue diameter by 25mm while keeping a neat connection within a compatible VIT-Smooth system.

Made from 1.2mm zero-carbon steel, the adaptor has vitreous enamel on its internal and external surfaces. In addition, its matt black finish coordinates with many wood-burning stoves, fireplace appliances and visible stove-pipe installations.

VIT-Smooth Flue Increaser Features

• Increases a 100mm (4-inch) flue connection to 125mm (5-inch)
• Manufacturer model number: 67-100-002
• Designed for compatible VIT-Smooth flue components
• Made from 1.2mm zero-carbon steel
• Approximately 1.4mm total thickness, including the enamel coating
• Internal and external vitreous enamel coating
• Heat-resistant matt black finish
• Friction-fit connection
• Suitable for compatible gas, oil and solid-fuel appliances
• Maximum continuous operating temperature: 600°C
• Product designation: EN 1856-2 T600 N1 Vm L80120 G375
• Minimum declared distance from combustible materials: 375mm
• Manufactured in the UK
• 12-year warranty, subject to the manufacturer’s terms

Technical Specification

• Product type: Increasing flue adaptor
• Lower connection: 100mm (4 inches)
• Upper connection: 125mm (5 inches)
• Diameter increase: 25mm
• Material: Zero-carbon steel
• Steel thickness: 1.2mm
• Coating: Internal and external vitreous enamel
• Finish: Matt black
• Joint type: Friction fit
• Temperature classification: T600
• Standard: EN 1856-2
• Product weight: Approximately 900g
• EAN: 5060795860475

What Is This Flue Increaser Used For?

This adaptor lets an installer continue from a 100mm VIT-Smooth stove-pipe connection into a compatible 125mm VIT-Smooth component. Therefore, it may help where the approved flue design requires the connecting pipe to increase from four inches to five inches.

However, the adaptor does not make an unsuitable flue system compliant. The appliance instructions, chimney design and current Building Regulations determine the required flue diameter. Therefore, ask a competent installer to confirm the correct size before ordering.

Why Choose VIT-Smooth?

VIT-Smooth combines strong steel with a smooth vitreous enamel coating. As a result, it provides a durable, heat-resistant finish for visible connecting flue pipes. Its matt black colour also complements many traditional and modern stove installations.

Furthermore, the internal coating helps protect the steel against combustion gases and condensates. The friction-fit design also creates a tidy connection between compatible parts when the system is assembled correctly.

Installation and Safety Information

Use VIT-Smooth only as a single-wall connecting flue pipe between a compatible appliance and a chimney, flexible liner or insulated twin-wall system. Never use this single-wall component to pass through a wall, ceiling, roof or concealed void.

Maintain at least the declared 375mm distance from combustible materials unless an approved installation method states otherwise. In addition, fit the smaller or male end downwards so moisture and condensate remain inside the flue system.

A competent installer should design and install the complete system. For solid-fuel work, use a suitably qualified installer, such as a HETAS-registered installer, or notify Building Control where required. Finally, follow the appliance instructions, the VIT-Smooth guide and current Building Regulations.

Product Guide

• Download the VIT-Smooth brochure

Why Buy from SNH Tradecentre?

• Competitive prices: We aim to offer excellent value across our flue and chimney range.
• Helpful product advice: Our team can help you identify compatible flue parts and diameters.
• Trade and public sales: We welcome installers, homeowners, landlords and property professionals.
• Collection available: IN STOCK Collect eligible in-stock products from our Birchington trade counter.
• UK delivery: Choose from available delivery services at checkout.
• Independent merchant: Buy from an established UK plumbing and heating supplier.

Need help checking compatibility? Call SNH Tradecentre on 01843 842727 before ordering. Our team can help you compare VIT-Smooth adaptors, pipes and other flue components.

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Frequently Asked Questions

What sizes does this stove-pipe increaser connect?

It connects a compatible 100mm VIT-Smooth flue pipe to a compatible 125mm VIT-Smooth component. Therefore, it increases the system diameter from four inches to five inches.

Can I use this adaptor with a wood-burning stove?

It may suit compatible solid-fuel appliances. However, the stove manufacturer’s instructions must permit the flue sizes and component type. A competent installer should confirm compatibility before installation.

Can this stove pipe pass through a wall or ceiling?

No. VIT-Smooth is a single-wall connecting flue system. Therefore, it must not pass through walls, ceilings, roofs or concealed spaces. These areas normally require a suitable insulated chimney system and the correct building components.

What is the maximum operating temperature?

The VIT-Smooth system carries a T600 classification, which indicates a maximum continuous operating temperature of 600°C. Always remain within the limits stated by the appliance and flue manufacturers.

How far should it be from combustible materials?

The product designation states a minimum distance of 375mm from combustible materials. However, the installer must assess the complete installation and follow the latest manufacturer guidance and Building Regulations.

Does the joint need fire cement?

The component uses a friction-fit connection, so fire cement is not normally required between compatible VIT-Smooth parts. However, the installer must follow the latest manufacturer instructions for the complete flue system.

Who should install this flue adaptor?

A competent installer should fit the adaptor as part of a properly designed flue system. For solid-fuel installations, consider using a HETAS-registered installer or arranging Building Control notification where required.

Manufacturers may update specifications and installation requirements. Therefore, check the latest VIT-Smooth literature and confirm compatibility before ordering or installing this component.