Solving Chimney Draught Problems

Smoke coming inside? Your chimney lacks draught, and there is a reason for it

A stove that smokes when lit, smoke odours in the house, a fire that fails to catch or dies out as soon as the door closes: these are all classic symptoms of chimney draught problems. The flue fails to generate the negative pressure the appliance needs, forcing the smoke to take the path of least resistance: into your room, onto your walls, and into your lungs.

We identify the root cause with a draught measurement and full diagnosis for 100 to 200 euros, which is fully offset against the cost if we carry out the solution. No guesswork, just knowing exactly what is going on first.

Nine out of 10 chimney draught problems stem from 1 of 6 causes: measuring first means paying only once for the right solution.

How we resolve a chimney draught problem

1. Step 1: mapping symptoms and situation

   When does it smoke: during ignition, in windy weather, when reloading, or when the extractor hood is running? Each of these patterns points in a different technical direction, and your answers speed up the diagnosis considerably. Sending a short video clip of the smoke behaviour helps our technicians even before their visit.

2. Step 2: draught measurement and flue inspection

   We measure the draught cold and warm, inspect the flue for blockages and leaks, and evaluate the terminal, surrounding structures, and air supply. If there is any doubt about the interior condition, our camera inspection captures the flue metre by metre.

3. Step 3: identifying the cause, pricing the solution

   You receive the cause in black and white, along with the proposed solution and a fixed price. If multiple factors are involved, we prioritize them by impact so you never pay more than necessary.

4. Step 4: execution and re-measurement

   After completing the work, we measure the draught again during an actual fire. We only consider the job done once the values are correct and the room remains completely smoke-free.

The 6 most common causes of chimney draught problems

A dirty or blocked flue, resolved with a chimney sweep costing 60 to 90 euros via our chimney sweeping service. A chimney terminal that is too low or poorly positioned below the ridge line or adjacent to higher structures. A cold, uninsulated flue that cools the flue gases down before they reach the top. An incorrect diameter for the appliance. Negative pressure inside the home caused by an extractor hood or ventilation system. And wind effects pushing smoke back down the flue, especially with tall trees or buildings within 15 metres.

How much does fixing a chimney draught problem cost?

The diagnostic inspection with draught measurement costs 100 to 200 euros, fully credited upon execution of the repairs. Solutions vary depending on the cause: sweeping costs 60 to 90 euros, installing a draught cowl or anti-downdraught cowl costs 100 to 300 euros, a chimney extension or new chimney pot costs 500 to 1,500 euros, lining the chimney costs 900 to 1,800 euros, and installing an external air supply costs a few hundred euros.

You will know every price upfront before making a decision. You can read the complete story in our guide on wood stoves smoking indoors.

When the house itself causes the problem

In well-insulated homes, the kitchen extractor hood or ventilation system frequently overpowers the chimney: the negative pressure pulls smoke directly into the room, especially during lighting. In this case, the solution lies not in the flue, but in the air supply: an external air intake of 80 to 100 millimetres or a room-sealed appliance. Our diagnosis tests this scenario as standard, comparing results with the extractor hood turned on and off.

Draught issues with a new or replacement stove

If an appliance smokes from day 1, the fault almost always lies in mismatching: a flue that is too wide for the compact flue gas stream of a modern stove, a connection with too many bends, or a terminal ending right in the roof pressure zone.

Modern stoves burn more efficiently and send smaller volumes of cooler flue gas up the chimney: what was adequate for an old stove may be too much flue for a new one. Diagnostic measurement makes this difference clear in actual numbers.

A permanent structural fix beats fighting symptoms

Fitting a cowl on a flue that is fundamentally too narrow or too cold simply shifts the problem to the next wind direction. That is why we always recommend a permanent structural solution alongside any quick fix, even if it costs more, allowing you to make an informed choice. Structural projects are handled via our chimney renovation service or a complete flue calculation, using the standards outlined on the Buildwise standards page as our benchmark.

Soot, odours and health: why delaying is costly

Smoke spilling indoors introduces fine dust and carbon monoxide into your living space, and every smoking fire leaves deposits on walls and furniture. A draught problem is never just a matter of comfort: the longer it persists, the higher the hidden costs. We schedule most diagnostic appointments within a week, giving priority during the heating season to customers who are hesitant to light their fire. One measurement ends the guesswork.