Pellet stove · Naples and Campania
Flue for a pellet stove: rules, cleaning and costs
The flue is half of the system: if it is wrong or dirty, even a good stove smokes, uses more pellet and goes into alarm. We inspect and clean it in Naples and Campania and, if it has to be rebuilt, we explain the compliant route up above the roof.
Quote before we start about 1 hour 30 minutesFull cleaning of the stove and a check of the flue
A dirty or blocked flue can push the stove's fumes and carbon monoxide, which has no smell, into the house. If you smell smoke, your eyes sting or you get a headache with the stove on, switch it off, throw the windows open and leave the room. A carbon monoxide detector near the stove raises the alarm before you notice.
Recognise the problem
- Smoke comes out of the door or the joints when the stove lights
- The stove goes into a draught alarm or a blocked flue alarm
- Little smoke, or dark smoke, comes out of the chimney cap
- The stove was fitted with a pipe that comes out of the wall and ends there
- You want to reuse the flue of an old fireplace or wood stove
The most common causes
- 1
Soot and ash
Even good pellet leaves residues in the flue duct, the pipe between stove and flue, and in the flue itself. They build up mostly in the bends and in the T-connector.
- 2
Chimney cap blocked or badly placed
Nests, leaves or a damaged cap close the outlet. If the cap is too low or close to obstacles, it ends up in the backflow zone, where the wind sends the fumes back.
- 3
Wrong route
Too many horizontal runs, too many bends or a diameter smaller than the one the manufacturer asks for take away draught. The stove's fan helps, but it does not make up for a badly made route.
- 4
Shared or leaking flue
A flue also used by another appliance, or an old masonry flue with cracks, can let fumes into rooms or neighbouring homes. With a fan pushing the fumes, tightness matters a great deal.
What you can safely check yourself
- Look behind the stove: there should be a T-connector with an inspection cap, through which the ash is removed.
- If the manual says so, with the stove cold open the cap and empty the ash: some manufacturers ask for this every 500 kg of pellet.
- With the stove on for a while, watch the chimney cap from the street or the balcony: the smoke should leave freely and clear, almost invisible.
- Look among your documents for the declaration of conformity of the flue and the logbook with the date of the last cleaning.
Never open the boiler or the gas water heater, and always switch off the power before touching an electrical appliance. If in doubt, call us.
When you need a technician at home
- Nobody has cleaned the flue in the last year
- The outlet goes through the wall or ends under a balcony
- You have to connect a new stove to an existing flue
- You smell smoke in your home or in the neighbours' flat
How much it costs
Cleaning a pellet stove flue
ProntoPro 2026 quotes: the low figure is for a short flue, the high one also includes cleaning the stove
85-180 €
New flue
ProntoPro range: a few metres on the outside are at the low end, an internal run up to the roof with masonry work at the high end
200-3.000 €
Market figures are indicative for the Naples area. You know our exact price before we start; prices apply near our base in Parete, and further away you see them in full when you choose your town.
Wall outlet or roof outlet?
For a pellet stove installed after 31 August 2013 the flue gases must exit above the roof, as DPR 412/1993 as updated that year states. The exceptions for wall discharge apply to some gas boilers, not to biomass.
The hole in the wall is acceptable only as a passage: the pipe crosses the wall and then rises vertically along the facade, usually in double-wall insulated steel, until it clears the roof with a chimney cap.
How far it must stick out depends on the slope of the roof and what is around: UNI 10683:2022 sets the outlet heights also according to obstacles, dormers and skylights, and on a usable terrace the heights change.
What the standard asks of the flue
The flue must serve only the stove, be made of materials suitable for pellet flue gases and stay accessible for inspection, with horizontal runs reduced to a minimum and slightly rising.
At the base a collection and inspection point is needed, and in the room an opening for air or a duct bringing outside air to the stove. At the end of the work the installer applies the flue plate with the data of the flue system and issues the declaration of conformity.
The flue of an old fireplace must first be inspected, often with a camera, and almost always lined with a steel duct suitable for pellet: UNI 10683 provides different checks for new flues, existing flues never used and flues already used.
Cleaning: how often and how we do it
The flue of a pellet stove must be cleaned at least once a year, as manufacturers' manuals indicate, and more often if the stove runs many hours a day. It is best done together with servicing the stove, so the final test is made with a clear outlet.
We clean the flue duct, the T-connector and the flue with brushes of the right diameter and an ash vacuum, and check the chimney cap when it can be reached safely. Camera inspections or complicated roof access are flagged to you beforehand, in the quote. The cleaning is noted in the logbook.
In Naples buildings a flue that starts on the lower floors rises the whole height of the building: the longer it is, the more it matters that it is straight, sealed and clean.
Want to know what it is first? Show us
Cleaning and inspection are done on site. On a video call, though, we can look with you at the connection behind the stove, the route of the flue and the chimney cap, and see whether there is an obvious defect, such as a wall discharge, before arranging the site visit.
Video consultation, up to 15 minutes: €9.90 (€14.90 on Sundays), deducted from the bill if we then come to your home.
Book the consultationDIY guides
Frequently asked questions
Can a pellet stove discharge through the wall?
No: since 31 August 2013 the outlet of a pellet stove must reach above the roof. The hole in the wall is only for the pipe to pass through, which then rises along the facade.
Can I connect the pellet stove to the boiler's flue?
No. The stove needs a dedicated flue that serves no other appliance. Two appliances on the same outlet disturb each other's draught and can bring fumes back into the house.
Do I need permission for an external flue in an apartment building?
It depends on the condominium rules and on how much the flue changes the facade. Usually it is best to go through the owners' meeting, and the Comune may ask for a building filing. For a listed building the opinion of the Soprintendenza is also needed.
How much does a flue for a pellet stove cost?
On ProntoPro quotes for a new flue run from about 200 to 3,000 €, depending on length, route and masonry work. Cleaning an existing flue starts from about 85 €.
You may also be interested in
Pellet stove all over Campania
We work in Naples, Posillipo, Caserta and all over the region. Near our base in Parete there is no travel cost; further away you see the full price before you confirm.
Ready when you need us.
Book your visit by choosing a day and time. For emergencies we answer 24 hours a day, across Campania.