Wood Pellet Stove Flue Pipe Size Considerations in Ireland
Choosing the correct flue pipe size for a wood pellet stove matters because it affects safe operation, clean combustion, and whether your installation aligns with Irish Building Regulations, including Part J requirements for heat producing appliances.
You are balancing manufacturer specifications with the realities of your home, such as whether you can use an existing chimney or need a twin-wall stainless-steel flue, the route to the roof, and the clearances required where the flue passes near combustible materials. Flue diameter and overall height work together to maintain stable draught and minimise issues like poor ignition, smoke spillage, or excessive condensation in the flue. In practice, many pellet stoves are designed around an 80 mm or 100 mm flue connection, with the final selection depending on the stove’s kW output, total flue run, and the number of bends.
You also need to account for ventilation, a reliable electrical supply for the stove and controls, and ongoing servicing so efficiency stays high and safety checks are routine. Once you have these constraints clear, it becomes easier to match your stove to a compliant flue setup that performs well in an Irish home.
Flue Requirements for Wood Pellet Stoves in Ireland
A wood pellet stove flue system is the pipework that safely carries exhaust gases outdoors while maintaining a stable draught for clean, efficient burning. It matters because the flue controls fumes, condensation, and fire risk, not just “where the smoke goes”. In practice, the right setup depends on your stove’s tested flue diameter and your route (straight up is usually simplest, rear-exit needs more planning). If the flue is undersized, poorly sealed, or badly terminated, you can end up with poor ignition, sooting, and nuisance shutdowns, which is why the details matter before you price anything.
Legal and safety baseline
A good starting point is that Irish Building Regulations guidance for heat-producing appliances is set out in Technical Guidance Document J – Heat Producing Appliances. That is why installers are so fussy about clearances, supports, suitable materials, and proper terminals, because a pellet stove is only as safe as the flue system it is connected to.
Typical Irish installations (and what you’ll price up)
Most homeowners end up choosing either a flexible liner in an existing chimney or a factory-made stainless twin-wall system, depending on the condition of the chimney, the route available, and the stove manufacturer’s requirements. If you’re costing parts, a 125mm complete flue kit for two-storey installations shows the kind of components that often get bundled together before you decide between relining a chimney or going with a stainless-steel flue system, and it also highlights why it is worth planning the full route before you commit to a stove.
Frequently Asked Questions About Wood Pellet Stove Flue Requirements in Ireland
Do pellet stoves need a flue in Ireland?
Yes. A pellet stove needs a suitable flue system to safely remove combustion gases to the outside and to maintain the correct draught for the appliance. The exact flue type, diameter, and termination details depend on the stove model and the manufacturer instructions, and the overall approach should align with Irish Building Regulations guidance in Technical Guidance Document J, so it is something you should confirm with a qualified installer before buying.
Can you run a pellet stove into an existing chimney?
Often, yes, but it depends on the chimney condition, sizing, and suitability for the specific stove. Many Irish installations use a flexible liner in an existing chimney to improve performance and help manage condensation and deposits, particularly in older or oversized chimneys. Your installer will normally check the chimney route, clearances, and terminal, and will match the liner and adaptor to the stove’s tested flue diameter so the system draws properly.
What flue size do pellet stoves typically use?
Pellet stoves vary by model, so you should always follow the manufacturer specification for the tested flue diameter. Many room-heater pellet stoves commonly use flue sizes around 80mm to 100mm, while some installations and component systems you’ll see in the market use 125mm parts depending on the appliance and setup. The key point is that you should not “upgrade” or “downsize” the flue based on guesswork, because the stove is tested to perform safely with a specific flue arrangement.
Is a twin-wall flue required for a pellet stove?
Not always. Twin-wall insulated flue is typically used when you do not have a suitable masonry chimney route, or where you need to run a flue externally or through different parts of the building while maintaining safe clearances and a stable flue temperature. If you already have a sound chimney, a flexible liner may be the more common solution. The right choice comes down to the route, the property, and the stove’s installation instructions, and it is best decided with an installer once the flue path is agreed.
Why do pellet stoves suffer from nuisance shutdowns if the flue is wrong?
Pellet stoves rely on controlled combustion and consistent draught. If the flue is undersized, restricted, leaking, or terminated in a spot that causes downdraught, the stove can struggle to ignite cleanly, the flame can become unstable, and the appliance may detect poor combustion and shut down for safety. In Irish conditions, condensation can also become an issue in colder or oversized flues, which is another reason correct sizing and an appropriate flue route make a noticeable difference in day-to-day reliability.
Get the Right Flue Parts for Your Pellet Stove Setup
If you are planning a pellet stove install, it pays to line up the flue route and components early so you are not forced into compromises later. Browse StoveBoss’s Flue Pipes & Accessories collection to compare liners, adaptors, bends, terminals, and full kit options, and shortlist what matches your stove’s specified diameter and your installer’s preferred approach. When you are ready to choose the appliance itself, the Wood Pellet Stoves Ireland collection is a handy place to narrow down models that suit Irish homes and real-world installation routes.
Choosing the right outlet matters because pellet stoves rely on stable, safe exhaust to run efficiently in Irish homes. Use what you already have where it is suitable, or add a purpose-built stainless-steel system where it gives you a cleaner, more reliable route. A full masonry chimney can work very well in older houses, but it often needs a liner and careful checks for leaks, poor draw, and damp-related issues. A stainless-steel flue system suits extensions, bungalows, and renovations because it can be routed internally or externally with more predictable performance. In both cases, the flue size and route should follow the stove manual and be designed and installed by a competent professional in line with Irish Building Regulations requirements for heat producing appliances and safe discharge of combustion products, including Part J provisions on air supply and carbon monoxide risk control in dwellings as amended in S.I. No. 133/2014.
How do chimney and stainless systems compare overall?
This choice usually comes down to what your house already has and how clean a flue route you can achieve. A good route reduces start-up smoke, nuisance smells, condensation in the flue, and maintenance headaches over a wet Irish winter, which is where the practical differences start to show.
Full chimneys
This route can be cost-effective if the chimney is structurally sound and correctly lined for the appliance. It also keeps the stove looking traditional in a fireplace opening, which many people prefer. The key is that “existing” does not automatically mean “ready”, especially where older chimneys have rough internal surfaces, historic leaks, or have been partly blocked or altered over the years, so condition and suitability are what decide whether it is genuinely the simpler option.
Stainless-steel flue systems
This option gives you a known flue path and modern components that are easier to inspect. It is also a common solution where you do not have a usable chimney, where the best stove position is away from the original fireplace, or where you are trying to avoid the unknowns of an older stack. If you are pricing parts, a typical basket starts with a kit like this 125mm complete flue kit for two-storey installations, and the final spec is usually dictated by the stove manufacturer’s required diameter, the route, and required clearances for the chosen system.
Which is best for you?
This decision is best made after an on-site look at clearances, termination point, and condensation risk. If you have no usable chimney, stainless is usually the straightforward answer, and if you do have a chimney, a proper assessment can confirm whether relining and remedial work will give you the same dependable draw and day-to-day cleanliness you would expect from a modern system.
Frequently Asked Questions About Chimneys vs Stainless-Steel Flue Systems
Can I use my existing chimney for a pellet stove in Ireland?
Often yes, but only if it is suitable for the appliance and in good condition. Many older Irish chimneys need a correctly sized liner and repairs to address leakage, poor draw, or damp penetration, and the installer will typically want to confirm the route, integrity, and termination arrangement before signing off. The stove manual matters here because pellet appliances can be sensitive to flue sizing and resistance, so the “it worked for an open fire” assumption is not a safe basis for a pellet installation.
Do pellet stoves need a stainless-steel flue system?
Not always. A pellet stove can be installed into a suitable masonry chimney with an appropriate liner, but a stainless-steel system is commonly chosen where there is no chimney, where the stove position is in an extension, or where you want a controlled, inspectable flue route with predictable performance. In Irish renovations, stainless twin-wall systems are a practical solution when you are trying to avoid structural changes to an existing chimney or when the original chimney is not economically repairable.
What flue diameter should I use for a pellet stove?
Use the diameter specified in the manufacturer’s installation manual and match the full system design to it. Pellet stoves vary, and a small change in diameter, length, or number of bends can affect draught and combustion performance, particularly in colder, wetter conditions where condensation can become an issue. A competent installer will design the route to meet the stove’s requirements and the relevant safety expectations under Irish Building Regulations Part J, including adequate air supply and safe discharge of combustion products as set out in S.I. No. 133/2014.
Is an external stainless flue a good idea in Ireland’s weather?
It can be, but it needs proper specification and installation. External runs can be more exposed to wind and low temperatures, which can increase condensation risk and affect performance if the route is marginal, so insulation, routing, termination height, and component quality matter. Many homeowners still choose external stainless systems because they avoid disrupting internal rooms and they give a clear, accessible path for inspection and maintenance, which becomes valuable over time.
Why does my installer keep talking about “draw” and “condensation”?
Draw is the natural movement of air and exhaust gases through the flue, and it is what helps the appliance run cleanly and safely. Condensation is the moisture that can form inside a cooler flue when warm exhaust meets cold surfaces, and Ireland’s damp climate can make this more noticeable where the flue cools quickly or the route is poorly insulated. Getting the route and sizing right reduces nuisance smells, tar deposits, corrosion risk, and the kind of intermittent issues that usually only show up on cold, still evenings.
Do I need a carbon monoxide alarm with a stove or flue installation?
In Ireland, carbon monoxide risk control is treated seriously under Building Regulations requirements for heat producing appliances in dwellings, including Part J provisions as amended in S.I. No. 133/2014. Your installer should advise on what is appropriate for your setup and where alarms should be located, and you should follow the alarm manufacturer’s instructions as well. Even with a well-designed flue, an alarm is a sensible last line of defence in day-to-day use.
Choose the Right Flue Parts for Your Installation
If you are planning a pellet stove installation or trying to decide whether your existing chimney is usable, it helps to price the correct components early, based on the diameter and route your installer recommends. Browse StoveBoss flue components and kits to shortlist what suits your layout and stove spec, and keep your basket aligned with manufacturer requirements and safe clearances from the start: Flue Pipes & Accessories.
Flue Height and Diameter Requirements
A flue needs enough height and the right diameter because that is what creates steady draught, keeps smoke and combustion gases moving safely outdoors, and stops your stove from running lazy and sooty. Proof matters here because manufacturers and Irish installers lean on published minimums and tested flue sizes to avoid poor combustion and fume spillage. The nuance is that elbows, long horizontal runs, and exposed twin-wall sections can all weaken draught even if you technically “meet the numbers”, so the route matters as much as the measurement.
Why does flue height have a minimum in Ireland?
Minimum height is about reliable updraught in real Irish weather, especially in windy or damp conditions where downdraught can be more of a nuisance. One Irish-market stove manual states that the minimum height of the flue or chimney must be 4.5 m from the hearth, which is why installers often treat 4.5 m as a practical baseline unless the specific appliance instructions say otherwise. Where the installation includes bends, offsets, or a more exposed external run, it is common to see the flue height and terminal choice doing more of the heavy lifting to keep draw stable.
What flue diameter is typical for solid-fuel and pellet stoves?
Diameter matters because it influences flue gas speed and temperature, and the same manual specifies a 150 mm flue outlet, which is a common benchmark across many solid-fuel models in Ireland. Pellet stoves often use smaller diameters, but the only safe way to choose is to follow the manufacturer’s stated flue size and any approved adapters, because reducing or incorrectly transitioning a flue can cause poor performance and increase the risk of fume spillage. Once you have the appliance outlet size pinned down, the real decision becomes choosing a suitable chimney liner or a stainless-steel twin-wall system that matches the route you actually have available.
Frequently Asked Questions About Flue Height and Diameter in Ireland
Is 4.5 m a legal minimum flue height in Ireland?
It is commonly treated as a practical minimum because many solid-fuel stove manuals supplied in the Irish market specify 4.5 m from the hearth to the top of the flue, such as this example from Henley Stoves: minimum height of the flue or chimney must be 4.5 m from the hearth. In reality, compliance is driven by the manufacturer installation instructions, the flue system certification, and the overall installation meeting Irish Building Regulations expectations, so your installer will size the height to the appliance and the route rather than chasing a single one-size-fits-all number.
Can you reduce the flue diameter if you cannot fit a 150 mm liner?
In general, you should not reduce the flue diameter below the appliance manufacturer’s specified outlet size unless the manufacturer explicitly allows it with an approved adapter and configuration. Undersizing can slow the evacuation of smoke and combustion gases, weaken draught, and increase the risk of fume spillage, especially in marginal chimneys or short flue runs. If space is tight, the sensible fix is usually choosing an appliance designed for a smaller outlet, or revisiting the flue route and system type with a qualified installer.
Do bends and horizontal runs really make that much difference?
Yes. Bends, offsets, and long horizontal sections add resistance and can cool the flue gases, both of which reduce effective draught. That is why two installations with the same total height can behave very differently in day-to-day use, particularly in exposed Irish locations where wind effects at the terminal can be unpredictable.
Is flue size the same as chimney size?
Not always. “Flue size” is the internal diameter that the gases actually travel through, such as a stainless-steel liner inside a masonry chimney or the internal diameter of a twin-wall insulated flue. A large old chimney can still have a correctly sized flue if it is lined to suit the stove, which is often done to improve safety, performance, and ease of sweeping.
Does a taller flue always mean a better stove draw?
A taller flue can improve draught, but it is not a magic cure on its own. Too much draw can make some stoves harder to control and can burn fuel faster, while poor terminal placement, cold external runs, or an oversized flue can still cause sluggish performance. The best results come from matching the appliance, the flue diameter, the height, and the route as a complete system.
Get Your Flue Plan Right Before You Buy
If you have your stove picked out, take five minutes to confirm the outlet size and sketch your flue route, including any bends and whether the run is internal or external. When you are ready to match parts properly, browse the flue pipes and accessories collection to shortlist the liners, twin-wall sections, adaptors, bends, and terminals that suit Irish installs, then sanity-check the full setup with a qualified installer before ordering.
Flue Regulations for Various Stove Types
Flue regulations are the safety rules that control how combustion gases are contained and discharged from your home. In practice, they govern flue sizing, materials, clearances, and termination so the appliance drafts properly and does not overheat nearby structure. Pellet stoves add an extra nuance because the flue must suit a fan-assisted, often lower-temperature exhaust, not just any chimney, and that changes what “compatible” really means when you are shopping.
Pellet vs wood/multi-fuel: what changes in the real world
Flue safety in Ireland is guided by national building standards, and the Government’s Technical Guidance Document J on Heat Producing Appliances sets out core requirements around the safe discharge of products of combustion for heat-producing appliances, including solid fuel. The key difference day-to-day is that wood-burning and multi-fuel stoves typically rely on natural draught and higher flue gas temperatures, while most pellet stoves use a combustion fan, have specific flue temperature and pressure characteristics, and can be far less forgiving of incorrect pipe, termination, or long, resistance-heavy runs.
That is why pellet stove manufacturers are usually very particular about:
The exact flue diameter and approved system (often a room-sealed or concentric option on some models).
Maximum equivalent flue length and limits on bends, because every bend adds resistance.
Condensate considerations in cooler flues, as lower-temperature exhaust can increase the risk of condensation if the system is not designed for it.
Termination location and wind effects, since fan-assisted appliances can still suffer from poor siting at the terminal.
Those points are not “extra nice-to-haves” in an Irish context. They are what keeps the appliance running cleanly and safely in damp weather, while also helping you avoid nuisance shutdowns, soot issues, or smell around the house when conditions are against you.
The practical takeaway before you buy pipe
If you are matching parts, start by confirming the manufacturer’s stated flue diameter and system type, then compare options in a single place like Flue Pipes & Accessories so your stove pipe, adapters, and terminal all stay within the same tested system. If anything about your route is unusual, like a long horizontal run, multiple offsets, a short chimney, or a tight clearance situation, it is worth getting an installer to sanity-check the design before you commit to components, because small changes in flue layout can make a big difference to performance.
Frequently Asked Questions About Flue Regulations for Stove Types in Ireland
Do pellet stoves have different flue requirements than wood-burning stoves in Ireland?
Yes, in practice they often do. Many pellet stoves are fan-assisted and may operate with lower flue gas temperatures than a traditional wood-burning or multi-fuel stove, so the flue system has to suit the appliance’s specified operating conditions. The safe approach in Ireland is to follow the stove manufacturer’s installation manual and ensure the overall installation aligns with the principles set out in Technical Guidance Document J, especially around safe discharge of combustion products and protection of the building fabric.
Can I use my existing chimney for a pellet stove?
Sometimes, but not automatically. Whether an existing chimney is suitable depends on the pellet stove model, the chimney condition, the liner requirement, and whether the route and termination meet the appliance manufacturer’s rules. Pellet appliances can be sensitive to flue resistance and condensation risk, so an installer will usually assess the chimney, recommend a suitable liner where required, and confirm that the final setup matches the stove’s tested configuration.
Is it OK to mix flue parts from different brands?
It is strongly discouraged. Flue components are designed and tested as a system, and mixing parts can create fit issues, unknown clearance requirements, or joints that are not properly rated for the appliance. Sticking with one compatible system, including the correct adapters and terminal, is a straightforward way to reduce avoidable problems and keep the installation easier to verify.
What is the main regulation I should know for solid-fuel flues in Ireland?
A key reference point is Technical Guidance Document J, which supports compliance with Ireland’s Building Regulations for heat-producing appliances. It sets out guidance on safe discharge of combustion products and broader safety expectations around the appliance and its connection to the building, while the manufacturer’s instructions remain essential for the exact flue diameter, layout limits, and required components for a specific stove.
Do I need a professional installer for flue work?
For most households, yes. Solid-fuel installations involve fire safety, safe clearances, correct termination, and ensuring the appliance works properly under Irish weather conditions. A qualified installer can confirm your flue route, specify the right system, and help avoid common issues like poor draw, condensation-related staining, or nuisance shutdowns on pellet stoves, all of which are harder and more expensive to fix after the fact.
Choose the Right Flue System for Your Stove Setup
If you have your stove model picked out, the most useful next step is to match a compatible flue system and keep all components within the same tested range. Browse Flue Pipes & Accessories to shortlist the right diameter pipe, adapters, and terminal for your intended route, then confirm the final layout against the manufacturer’s instructions and Irish guidance in Technical Guidance Document J before you buy.
Plan a safe pellet stove installation in Ireland by sizing the stove to how you use the room, confirming you have adequate ventilation and a compliant flue route, and making sure there is a suitable electrical supply for ignition and the pellet feed. Keep everything aligned with the manufacturer’s installation manual and Irish Building Regulations guidance for heat-producing appliances, including Technical Guidance Document J (Part J). If anything feels “nearly right”, stop and get it checked before you buy parts, because small compromises on clearances, air, or flue design are where problems tend to start.
1. Match kW output to the room
Start by sizing for comfort, because an oversized stove tends to cycle, run inefficiently, and can leave the room feeling stuffy. Browse typical outputs in wood pellet stoves for Irish homes and note whether you’re heating one room only or trying to move heat into other spaces, as that decision changes the type of unit and the install approach.
2. Confirm ventilation and air supply
Check ventilation early, because pellet stoves still need dependable combustion air and negative pressure in the room can lead to poor burning and nuisance issues. Your installer should assess existing vents, the impact of draught-proofing, and whether an external air kit is needed, especially in tighter, upgraded Irish homes where the stove can end up competing with extractor fans and other appliances for air.
3. Plan electrics and use a professional installer
Confirm a suitable socket location, cable route, and safe isolation, because pellet stoves rely on power for ignition, controls, and the pellet feed system. Use a competent, suitably qualified installer to sign off clearances to combustibles, hearth and floor protection, and flue commissioning in line with the manufacturer’s instructions and Irish guidance, as that practical sign-off is what gives you confidence when weighing up chimney use versus a dedicated stainless-steel flue system.
Maintenance and Efficiency of Pellet Stoves
Experts generally agree that pellet stoves stay safest and cheapest to run when you treat “after installation” as the start of a routine, not the finish line. SEAI’s domestic technical standards are a good yardstick because they reflect what’s expected in Irish homes, where airtightness and ventilation can be a tricky balance. What you actually need to do varies with your flue route, pellet quality, and how many hours a day you burn, so it pays to keep the basics consistent and build from there.
Post-installation safety checks
Start with commissioning checks, because a small leak at a joint can become a big CO risk. SEAI notes that a carbon monoxide (CO) alarm should be provided for solid-fuel installations under its Domestic Technical Standards and Specifications, and that is a simple layer of protection you will actually notice day-to-day. Once you have safety covered, the same attention to detail shows up again in cleaning and servicing, which is where efficiency is won or lost.
Cleaning, servicing, and efficiency tips (Ireland)
Empty ash little-and-often, vacuum the burn pot, and keep air inlets clear so ignition stays quick and smoke stays low.
Book an annual service before winter; it protects parts, stabilises fuel use, and catches gasket wear early.
Run steady, not stop-start, and use dry, consistent pellets; if you are comparing options, the wood pellet stoves range shows typical control features that help modulate heat smoothly, which can make day-to-day running feel a lot more predictable.
How Flue Choices Impact Heating Efficiency
Choose the wrong flue and you’ll feel it fast: the stove runs lazy, lights poorly, and you burn more fuel to get the same warmth. The proof is simple installer reality: poor draught and leaky routes steal heat and upset combustion. Over a winter, that shows up as higher running costs and more soot, and it can be worse in older Irish homes with oversized chimneys.
Draft and air leaks: where efficiency quietly disappears
Draught control matters because too much pull drags warm room air up the chimney. SEAI’s BER methodology flags fireplaces and chimneys as major ventilation pathways in the DEAP Manual, which is why a sealed, correctly routed flue pays back in comfort. That same “sealed and sound” thinking also helps you keep flue gases hot enough to behave properly.
Condensation and deposits: the long-tail cost
Flue temperature matters because cooler, poorly insulated runs encourage condensation and tar. SEAI notes that changes to airtightness can affect ventilation and heating system performance in its Domestic Technical Standards and Specifications, so the “cheap” flue choice often becomes a cleaning-and-servicing bill later, especially in Ireland’s damp, shoulder-season weather when stoves are run at lower burn rates. Keeping the system warm, stable, and correctly matched is what supports clean combustion day to day.
What flue or chimney does a wood pellet stove require in an Irish home?
A wood pellet stove in Ireland must be connected to a dedicated flue system that is suitable for solid-fuel combustion products, correctly sized to the stove’s outlet, and installed to comply with Irish safety guidance for heat producing appliances.
In practice, that usually means either using an existing, sound chimney that has been appropriately lined for the appliance, or installing a purpose-made factory-built flue system (commonly an insulated stainless-steel system) designed for stoves, with the final specification driven by the stove manufacturer’s installation instructions and the site layout. If you want a practical checklist view of what installers look at, see our guide to wood pellet stove installation in Ireland.
Do pellet stoves in Ireland need a full chimney, or can they use a stainless-steel flue system instead?
You do not need a full masonry chimney to install a pellet stove in many Irish homes, provided you can install a compliant flue system that safely conveys the products of combustion to outside air.
A stainless-steel flue system is commonly used for retrofits and extensions because it can be routed internally or externally and insulated where required, but it still needs to meet the stove’s technical requirements and the same core Irish safety principles around flue integrity, termination position, and separation from combustibles. Where a chimney already exists, relining is often the safer route than trying to use an unlined, oversized, or degraded flue. Related background is covered in our overview of solid-fuel stove regulations in Ireland.
What minimum flue height is required for a stove installation in Ireland?
There is not a single universal flue height that suits every stove and every house, so the minimum is set by a combination of Irish guidance and the specific appliance instructions.
Many stove manuals used in Ireland specify a minimum overall flue height of 4.5 m measured from the hearth to the flue terminal, which is why installers commonly treat 4.5 m as a practical baseline where the manufacturer allows it and the termination position is suitable for the roofline and nearby openings (Henley Stoves manual).
Do the same flue regulations apply to wood pellet stoves as to wood-burning and multi-fuel stoves?
Broadly, yes. A pellet stove is still a heat producing appliance that must safely discharge combustion gases, so the same Irish safety themes apply around using the correct flue type, maintaining separation from combustible materials, providing suitable access for inspection and cleaning, and following the appliance manufacturer’s instructions.
Where pellet stoves can differ is in how the appliance is designed to operate and what the manufacturer allows for flue layout, diameter, and components, so you should treat the installation manual as non-negotiable and use Irish guidance as the framework around it. Our pellet stove installation guidance for Ireland explains what tends to be checked on real installations.
What clearances to combustibles and hearth dimensions are required by Irish Building Regulations?
Irish requirements depend on the appliance type, tested clearances stated by the manufacturer, and whether the stove is installed in front of a non-combustible recess, on a constructional hearth, or on a suitably rated superimposed hearth.
As a common baseline used in Irish guidance for solid-fuel roomheaters, a hearth typically needs to project at least 300 mm in front of the appliance and 150 mm to each side, unless the appliance instructions allow a reduced dimension for a tested installation (StoveBoss guidance on Irish stove regulations).
Clearances to combustibles are also manufacturer-led, but the key is that any combustible wall, beam, or mantel within the stove’s declared clearance zone must be protected or moved so the installation remains within the tested distances, which is where a quick expert sense-check can save a lot of rework and worry before you commit to a stove and flue plan.
If you want practical, Ireland-specific tips on cleaner heat, stove sizing, and what to look out for on flue and installation planning, subscribe to our newsletter and keep your options open.
When you are ready to compare models and choose an efficient appliance for your home, browse our range of wood pellet stoves.