How to choose the right flue and accessories for solid fuel stoves

When setting up a solid fuel stove, selecting the correct flue and accessories is essential for ensuring efficiency, safety, and long-term performance.

Flues are designed to expel the combustion gases from your stove, and choosing the right one depends on the type of stove, the fuel used, and the installation requirements.

In this article, we’ll explore the different types of flue systems available and match them with the appropriate stoves to help you make the best choice for your heating setup.

The Difference Between Flues

Flues are essentially pipes that vent the smoke and gases produced by a stove, ensuring proper air circulation and keeping the air inside your home safe.

Flue systems are made from various materials and have different properties that make them suitable for specific applications.

• Single Wall Flue (System 1): This is a more basic option, typically made from stainless steel, and is used to connect a stove to an existing chimney and is suitable for multi fuel and wood burning appliances. It’s ideal for situations where the stove is already connected to a traditional flue or chimney system.
• Twin Wall Flue (System 2): Twin wall flues are insulated, making them more efficient for keeping heat within the pipe and allowing the gases to vent at higher temperatures. These are ideal where there is no existing chimney or the building of one may not be possible, or for stoves installed in a variety of environments, including residential, commercial, or industrial applications.
• Vitreous Enamelled Steel Flue (System 7): This system is specially designed to connect stoves to an existing lined chimney or to a twin wall flue pipe. It’s produced using carbon steel coated with an enamel for added durability and resistance to high temperatures, making it a good choice for stoves that will be used frequently. It’s more aesthetically pleasing as it’s coloured and often matched to the colour of the stove
• Pellet Stove Flue (System 8): Specifically designed for pellet stoves, this system is built to handle the high pressure created by the fan in the combustion circuit. These flues are also known for their high-efficiency properties, ideal for homes looking to use pellets as a sustainable fuel source.
• Flexible Flue Liners (System 35): System 35 flue liners are made from 904 grade stainless steel and are flexible, making them perfect for relining existing masonry chimneys. These liners are suited for solid fuel, oil, gas, and multi-fuel appliances and are particularly effective in condensing applications, where lower temperatures are required for efficient venting.

Which Flue System Is Best for Your Stove?

When selecting a flue system for your stove, it’s important to choose one that matches both the stove and the fuel being used.

For example, pellet stoves require a flue system that can handle the higher pressure generated by the combustion fan, so System 8 is a great match.

If installed within an existing masonry chimney, solid fuel insert stoves require a combination of system 1 and system 35 in order to direct the new flue correctly.

The Difference Between Stoves

Stoves come in various types and sizes, each with unique features to suit different heating needs.

The two main categories are multi-fuel stoves and wood stoves, but they can also include pellet stoves and boiler stoves that are specifically designed to heat water for central heating systems.

• Multi-fuel Stoves: These are designed to burn a variety of fuels, including wood, coal, peat, or even compressed logs. Multi-fuel stoves tend to require a more versatile flue system due to the various gases and particulate matter produced by different fuels.
• Wood Stoves: These stoves are designed specifically for burning wood, and they require flue systems that are capable of handling the moisture content and acidity that comes from burning wood logs.
• Pellet Stoves: These stoves are powered by pellets, which are compressed from wood waste, and they require specific flue systems designed to handle the high pressure created by the fan in the combustion circuit.
• Boiler Stoves: These are larger units designed to heat both the room and provide hot water for use in a central heating system and domestic hot water. They generally use the same flue systems as multi-fuel stoves that do not include a back boiler. However, the specific flue system or combination of systems used depends on the physical layout of the building. For example, if there’s an existing chimney, the system can connect directly to it, while in other cases, additional systems might be required to adapt to the building’s structure and ensure safe and efficient venting.

Matching the Right Flue to Your Stove

Now that we’ve looked at the different types of flues and stoves, let’s see how to pair them effectively for optimal performance in various scenarios:

Henley Severn 8kW Multi-Fuel Eco Stove installed in a setting without an existing chimney

Flue Match: Combination of Mi-Flues System 7 and System 2 Twin Wall Insulated Stainless Steel Chimney.

This multi-fuel stove, suitable for burning wood, coal, and other solid fuels, requires a robust flue setup. Typically, Mi-Flues System 7 is used for the initial connection directly to the stove, as it provides the necessary durability and heat resistance for the immediate venting needs. Beyond this point, System 2, with its twin wall insulation, is ideal for continuing the flue through external walls, attic spaces, or through the roof, ensuring safe and efficient venting in residential installations.

Henley Pellet Stove 8kW ELM 8

Flue Match: Mi-Flues System 8 Vitreous Enamelled Flue Pipes, with optional integration of System 35 or System 2.

As a pellet stove, this model requires a flue system that can handle the high pressure generated by the combustion fan. Mi-Flues System 8 is specifically designed for pellet stoves, ensuring safe and efficient operation. If the installation involves an existing masonry chimney, System 35 can be used to connect to it seamlessly. In settings without an existing chimney, System 2 can be employed to continue the flue through walls or up through the roof, providing flexibility and optimal performance for residential installations.

Stanley Reginald Stove 23kW with Boiler

Flue Match: Combination of Mi-Flues System 7 and System 35 Flexible Flue Liners

This large stove, designed for solid fuel use and equipped with a boiler for central heating, requires a robust flue setup to handle its higher heat output. Typically, Mi-Flues System 7 is used for the initial connection directly to the stove, providing the heat resistance needed at the appliance. From there, System 35 flexible flue liners are ideal for relining older chimneys, ensuring both durability and effective performance for central heating applications.

Henley Muckross Insert Stove 4.6kW

Flue Match: Mi-Flues System 7 Vitreous Enamelled Steel Flue, with optional adaptation to System 35.

The Muckross stove is an insert model, which typically connects to an existing chimney flue. Mi-Flues System 7 is an ideal choice for this type of installation, providing the durability needed for long-term performance. If the existing masonry or clay flue liners are in good condition, System 7 can connect directly. However, if the existing liners need reinforcement, System 35 can be adapted for added reliability.

Stanley Erin Boiler Stove 20kW / 14.2kW

Flue Match: Mi-Flues System 2 Twin Wall Insulated Stainless Steel Chimney

The Stanley Erin is a large boiler stove, which means it will generate substantial heat. The Mi-Flues System 2 twin wall system is ideal for handling the high heat output while maintaining efficiency and safety in both residential and commercial installations.

Choosing the right flue and accessories for your solid fuel stove is essential for ensuring safety, efficiency, and durability.

By understanding the different flue and matching them to the specific needs of your stove, you can optimise performance and enjoy warmth for years to come.

For any further questions or personalised assistance, don’t hesitate to reach out.

Our team is here to ensure you choose the best flue system for your stove, so you can enjoy efficient and safe heating all year round.

Just send an email to info@mybuildingsupplies.ie or call: 0818 888 000.