A wood burning stove can be a brilliant addition to any home — providing reliable heat, reducing reliance on the central heating system, and adding charm and comfort to a space. But like any major home upgrade, the installation process comes with its own set of challenges. Even small mistakes during installation can have big consequences for safety, performance, and legal compliance.
Whether you're taking the DIY route or hiring a professional, being aware of the most common pitfalls can save you time, money, and future headaches. Here are the top five mistakes people make when installing a wood burning stove — and how you can avoid them.
1. Failing to Line the Chimney Properly
If your property has an existing chimney, it might be tempting to skip installing a chimney flue especially if the chimney looks solid from the outside. But this is one of the most critical mistakes homeowners make.
A flue liner is essential for ensuring that smoke, gases, and soot are safely transported out of your home. It protects the inside of the chimney from corrosive condensates, improves the stove’s efficiency, and helps create a stable draft. Most importantly, it reduces the risk of carbon monoxide leakage and chimney fires.
Without a liner, old chimneys — especially those designed for open fires — are often too large or cracked to safely serve a modern stove. This can result in poor draw, creosote build-up, and hazardous leaks.
How to avoid it:
Always install a proper flue liner when fitting a wood burning stove into an existing chimney flue, unless you have written confirmation from a HETAS-certified installer that it is not necessary. In most cases, a flexible stainless steel liner will be used, sized according to your stove’s requirements.
2. Choosing the Wrong Size Stove for the Room
Bigger isn’t always better. One of the most common buyer mistakes is choosing a stove with too high a heat output for the space.
A stove that’s too powerful will overheat your room quickly, leading to discomfort and encouraging people to underfire the stove — causing incomplete combustion, more smoke, and increased creosote build-up. Conversely, a stove that’s too small may struggle to warm the room and tempt users to overfire, which can damage both the appliance and the flue system.
How to avoid it:
Measure your room and calculate the required kilowatt output using an online calculator or with help from your stove supplier. As a rough guide: for every 14 cubic metres of space, you’ll need 1kW of heat. Factor in insulation, windows, ceiling height, and how airtight your home is.
3. Poor Flue Pipe Design and Layout
The design of the flue system is just as important as the stove itself. If the flue pipe is too short, too horizontal, or contains too many bends, it will struggle to create a proper draft. This can result in sluggish fires, excessive smoke, and even backdrafting of dangerous gases.
How to avoid it:
Follow Building Regulations Part J, which provides detailed guidance on minimum flue heights and configurations. Ensure your flue:
● Is at least 4.5 metres in height (from stove to terminal)
● Has no more than two 45-degree bends
● Terminates above the roofline at the required height (typically 600mm above the ridge or 1,000mm from flat roofs)
● Has enough clearance from windows, vents, and neighbouring buildings
These details are especially important if you're installing a twin-wall external flue or making significant changes to the chimney flue structure.
4. Ignoring Ventilation Requirements
Wood burning stoves need a steady supply of air to maintain a clean and efficient burn. In modern, airtight homes, a lack of airflow is a common cause of poor stove performance. Without sufficient ventilation, the stove may burn erratically, produce more smoke, and increase the risk of carbon monoxide build-up.
How to avoid it:
UK Building Regulations require that stoves over 5kW output must have a dedicated air vent. But even for smaller stoves, it’s wise to ensure adequate airflow — especially in newer properties. Install a permanent, non-closable vent that feeds fresh air from outside, and avoid placing extractor fans in the same room as your stove.
5. DIY Installations Without Certification
With so much online advice available, it's easy to believe you can install a stove yourself. And while it is legally possible to do a DIY installation, it’s a risky move unless you’re extremely experienced — and even then, you’ll need to go through the right channels.
A poorly installed stove can result in leaks, chimney fires, smoke damage, or worse. Insurance companies may also refuse to cover damages from uncertified work.
How to avoid it:
Hire a HETAS-registered installer, who is trained to meet all safety and building code standards. If you do choose to install it yourself, you must submit a Building Notice to your local council and have the installation inspected and approved. Only then will it be legal and insurable.
Final Thoughts
A wood burning stove can transform your home — but only if it’s installed correctly. Whether it’s skipping a flue liner, underestimating ventilation, or misjudging flue pipe layout, the mistakes covered here are all too common but completely avoidable.
Take the time to plan carefully, follow UK Building Regulations, and consult with certified professionals when needed. That way, your stove won’t just look great — it will heat your home safely, efficiently, and legally for years to come.