ATTACK KT chimney, diameter 60/100, lacquered

Product detailed description

ATTACK KT chimney, diameter 60/100, painted finish is part of the original flue gas exhaust and combustion air intake system ATTACK KT / KT PLUS, designed for wall-mounted condensing gas boilers ATTACK Condensing. This part belongs to the category: chimney – final roof/facade element with a storm collar, diameter 60/100 mm, made of galvanized steel with a painted surface finish.

Closed combustion chamber and flue gas exhaust for ATTACK condensing boilers

ATTACK condensing gas boilers operate with a closed (turbo) combustion chamber – unlike older atmospheric boilers, they do not need air from the room in which they are installed, nor a functional masonry chimney. They draw combustion air directly from outside the building and exhaust flue gases outside also by forced draught, provided by a fan built into the boiler. In practice, this closed circuit is solved in two ways: by a coaxial (concentric) pipe, where a smaller pipe for air intake runs inside a larger pipe and the annular space serves for flue gas exhaust, or by a separate system with two independent pipes. The coaxial version with a diameter of 60/100 mm is the most common solution for boilers up to approx. 35 kW, as it allows both exhaust and intake to be routed through a single opening in the wall or roof, is quick to install and aesthetically unobtrusive.

Every element of the exhaust assembly – bend, extension, condensate collector, chimney end piece and manifold – must be airtight, resistant to flue gas temperatures as well as to condensate, which forms in large quantities during operation of a condensing boiler precisely because the boiler is able to utilize the latent heat of the water vapour in the flue gas. It is this condensate that is the reason why the ATTACK KT system cannot be safely replaced with an ordinary chimney part intended for atmospheric boilers – such parts are not designed for permanent contact with acidic condensate, nor for the correct gradient that drains the condensate back to the boiler or to the collector.

Chimney end piece – the final element of the route through the roof or facade

The chimney part is the last link of the exhaust route where the pipe leaves the building – most often through the roof structure. It contains a storm collar (sleeve), which is overlapped by the roof covering during installation and ensures the watertightness of the penetration, and an end grille/cover, which prevents rainwater, snow and insects from entering the intake part of the pipe while maintaining a free cross-section for both intake and exhaust.

During installation, it is crucial to observe the minimum height of the outlet above the roof plane and the minimum clearance distances from windows, ventilation openings and neighbouring property boundaries according to the applicable standard (EN 15287) and according to the installation manual of the specific boiler – an incorrectly positioned end piece can cause re-intake of its own flue gases or cause nuisance to neighbours from odour and moisture.

Example of a typical connection in a real installation:
boiler → 1 m extension → 90° bend → vertical riser pipe through the roof → chimney (roof end piece with collar).

Step-by-step installation procedure

1. Determine the exact location of the roof penetration with regard to the minimum height above the roof plane and clearances according to EN 15287.
2. Cut an opening in the roof covering and fit the storm collar so that it overlaps the covering to the extent specified by its manufacturer.
3. Connect the chimney part to the vertical riser pipe from below, seal the joint and secure it mechanically.
4. Check the watertightness of the penetration (visually, or by a water test) before finishing the roof covering around the collar.
5. After the first rain following installation, we recommend a visual check of the penetration's tightness from the attic.

Material and construction

This part is made of galvanized steel with an additional painted surface finish, which increases resistance to weather conditions on the exterior part of the route (e.g. the chimney end piece on the roof) and at the same time gives the part an aesthetic, uniform appearance matching the design of ATTACK Condensing boilers. The surface finish withstands normal flue gas temperatures from a condensing boiler and short-term contact with condensate, provided the correct pipe slope is maintained, which ensures that condensate does not stand in the part for long periods.

System classification: coaxial (concentric). Design: vertical, penetration through the roof or facade.

Compatibility with ATTACK boilers

The PR39 part is intended for the connection system common to the entire range of wall-mounted condensing boilers ATTACK ACKT20, ACKT28 and ACKT48 (Condensing KT range), ATTACK KST24 (Condensing KST) and ATTACK KZT25 (Condensing KZT). Before ordering, we recommend verifying in the installation manual for the specific boiler model the exact type of connection socket and the maximum permitted length of the exhaust route, as this may vary slightly depending on the boiler output (20, 28 or 48 kW for the KT range).

Installation and warnings

When installing the chimney end piece, the storm collar is first fitted so that it overlaps the roof covering by at least the extent specified by the roof covering manufacturer, and only then is it connected to the vertical riser pipe. It is important to observe the minimum height of the outlet above the roof plane (generally at least 0.4 – 0.5 m depending on the roof pitch and the EN 15287 standard) and the clearance from windows, terraces and property boundaries.

As a general rule, horizontal sections of the exhaust must have a gradient of at least 3° towards the boiler or towards the nearest condensate collector, so that condensate does not accumulate in the pipe. Installation should be carried out by a person qualified to install gas appliances and their exhaust systems, in accordance with the installation manual for the specific boiler and with the EN 15287 standard.

Standards and safety requirements

Installation of flue gas exhaust for condensing boilers in Slovakia is governed primarily by the EN 15287 standard (Chimneys – Design, installation and commissioning of chimneys – Part 1: Chimneys for fan assisted appliances), which sets out the minimum clearances of the outlet from windows, ventilation openings, neighbouring properties and ground level, as well as the minimum height of the outlet above the roof plane. The boiler itself and its exhaust system must also meet the requirements of EN 483 (type C gas boilers) and be installed in accordance with the technical operating regulations applicable to gas appliances.

Installation may only be carried out by a person qualified to install and service gas appliances, who, upon completion, issues an inspection report or commissioning protocol. In the event of any change to the route compared to the originally approved design (e.g. additional extension of the route, change in the number of bends), it is necessary to check whether the boiler is still within the parameters permitted by the manufacturer – otherwise there is a risk not only of boiler malfunction but also of loss of warranty and, in extreme cases, a safety risk of flue gas leakage.

Maintenance and service inspection

The chimney end piece is the most exposed to weather conditions, so it is recommended to check its condition (grille, collar, seal) at least once a year – especially before and after the winter period, when it may become blocked by snow or ice, or mechanically damaged by ice falling from the roof.

The recommended inspection interval for the entire exhaust route is once a year, usually as part of the regular boiler service inspection carried out by an authorized service technician. On this occasion, this specific part is also checked, along with the patency of the condensate path and the overall condition of the joints along the entire route from the boiler to the outlet outside the building.

Typical usage scenarios

Scenario 1 – new building with a vertically routed path through the attic: the boiler is located in a utility room on the top floor, the route rises directly to the roof, and the chimney end piece handles the final penetration through the covering.

Scenario 2 – renovation of a house with an original masonry chimney: the masonry chimney is no longer used as a functional draught, but as a shaft for routing the new plastic-aluminium pipe; the chimney end piece is fitted on top of the original chimney body.

Related parts in the ATTACK KT range

The coaxial chimney end piece PR39 is intended for roof penetration; for facade (horizontal) outlets, the end pipe PR44 is used instead. When switching to a separate Ø80/Ø80 system (e.g. via the manifold PR51), a chimney set for diameter 80 mm, PR50, is used instead of PR39.

A complete overview of all parts of the ATTACK KT / KT PLUS flue gas exhaust system (bends, extensions, chimney end pieces, condensate collectors and manifolds for diameters 60/100 mm and 80 mm) can be found in the category Condensing boilers > flue exhausts, flue pipes > accessories by brand > Attack on this e-shop.

Summary

ATTACK KT chimney, diameter 60/100, painted finish (code PR39) is a chimney-type part – final roof/facade element with a storm collar with a diameter of 60/100 mm made of galvanized steel with a painted surface finish, belonging to the coaxial (concentric) system. Recommended installation orientation: vertical, penetration through the roof or facade. The part is intended for boilers ATTACK ACKT20, ACKT28 and ACKT48 (Condensing KT range), ATTACK KST24 (Condensing KST) and ATTACK KZT25 (Condensing KZT), and is part of the broader range of ATTACK KT exhaust parts available on this e-shop, allowing you to assemble a complete flue gas exhaust route exactly according to the layout of the specific installation.

Frequently Asked Questions

Can the PR39 chimney end piece also be used for a facade (non-roof) penetration?
The PR39 part is designed primarily for vertical penetration through the roof, including a storm collar to overlap the covering. For facade (horizontal) outlets, the horizontal end pipe PR44 is used instead, which does not have a roof collar but a side protective grille.

Does the PR39 chimney end piece also include protection against birds and insects?
Yes, the part's end grille prevents birds, insects and larger debris from entering the intake part of the pipe while maintaining a sufficient free cross-section for both air intake and flue gas exhaust according to the boiler's dimensioning.

Do I need a functional chimney for an ATTACK condensing boiler?
No. ATTACK Condensing KT, KST and KZT condensing boilers have a closed combustion chamber with forced draught – they draw combustion air from outside and exhaust flue gases through their own exhaust system (coaxial 60/100 mm or separate Ø80/Ø80). A masonry chimney is therefore not required; a penetration through the wall or roof for the plastic-aluminium pipe is sufficient.

What is the maximum length of flue gas exhaust for a coaxial 60/100 mm pipe?
The exact value depends on the specific boiler model (ACKT20, ACKT28, ACKT48, KST24 or KZT25) and is stated in the installation manual – typically the equivalent length is 10 – 15 m, with a 90° bend counted as approx. 1 – 1.5 m and a 45° bend as approx. 0.5 m of straight pipe. Exceeding the limit increases resistance and may cause a boiler fault message.

Why does water actually drip from the flue gas exhaust?
A condensing boiler cools the flue gas so much that the water vapour contained in it condenses – it is precisely from this heat that the boiler additionally gains its high efficiency. The resulting condensate is mildly acidic and must be drained via the condensate collector to the boiler's siphon; that is why all horizontal pipe sections are required to have a gradient towards the boiler or the collector.

Can the coaxial 60/100 mm pipe be combined with a separate Ø80/Ø80 system?
Yes, that is exactly the purpose of the manifold (e.g. PR51, PR51A or PR51B), which splits a single coaxial pipe from the boiler into two separate Ø80 mm pipes. It is used for longer routes or when the intake and exhaust need to be routed in different directions.

Can I combine parts of different diameters or from another manufacturer with the ATTACK exhaust system?
It is recommended to use a certified system from the same manufacturer as specified in the manual for the specific boiler (for ATTACK Condensing boilers this is the ATTACK KT/KT PLUS system). Combining parts of different diameters, materials or from other manufacturers may result in leaks, incorrect condensate drainage and loss of the boiler warranty.

How often should the exhaust pipe and condensate collector be checked?
A visual check of the tightness of the joints and the patency of the condensate collector is recommended at least once a year, ideally during the regular boiler service inspection. For facade or roof outlets, it is also necessary to check that the end piece grille is not blocked by leaves, insects or snow.

Does the flue gas exhaust need to be insulated?
When the exhaust runs through a heated space, insulation is usually not necessary, as the surface temperature of the coaxial pipe is low. For longer sections routed through an unheated space (attic, facade) or where there is a risk of moisture condensing on the pipe surface, additional insulation is recommended, especially at the condensate collector, to prevent it from freezing.

What happens if the flue gas exhaust is undersized or too long?
If the maximum equivalent exhaust length is exceeded or there are leaks, the boiler will generally report a fault related to flue gas/air flow (fan fault, pressure switch fault or flue path fault) and shut down for safety reasons. The solution is to recalculate the route according to the manual and possibly adjust it (shorter route, fewer bends, or switching to a separate Ø80/Ø80 system).

Can this part also be used in a cascade connection of multiple boilers?
In cascades with multiple boilers, a separate Ø80/Ø80 system with a common collecting chimney is generally used, or separate end pieces for each boiler according to the cascade project documentation. The specific components (extensions, bends, manifolds) are also compatible in this configuration, but the minimum outlet clearances according to EN 15287 must be observed.

How do I know exactly which parts I need for my installation?
The most reliable way is to follow the installation manual for the specific boiler model (ACKT20/28/48, KST24, KZT25), which contains diagrams of typical configurations and maximum permitted lengths. For a more complex or unusual layout (long route, penetration through multiple floors, cascade), we recommend consulting an installation company or directly the seller before ordering the exact number of pieces.

Does condensate from the flue gas exhaust need to be neutralized before being discharged into the sewer?
For typical family houses with a small boiler output, neutralization is generally not required due to the small amount of condensate and its dilution with other wastewater; however, applicable legislation and the requirements of the local sewer authority must be followed. For larger outputs or cascades of boilers, it is recommended to install a condensate neutralization device before discharging it into the public sewer.

Is operating a condensing boiler with this type of exhaust noisier than with a classic chimney?
Forced draught (from the boiler fan) may be associated with slight operational noise, but with a correctly installed and mechanically secured route (without freely vibrating pipe sections) this is minimal and generally comparable to or lower than the noise of a classic atmospheric boiler with chimney exhaust.

Can this part be installed by myself, or is a professional required?
The mechanical connection of the parts themselves (push-fit system) is simple, but connecting the exhaust to the condensing boiler, calculating the maximum route length and commissioning the boiler must be carried out by a person qualified to install gas appliances – this is both a manufacturer's requirement and a legal requirement for maintaining the warranty and ensuring safe operation.

Does the number and type of these parts affect gas consumption or boiler efficiency?
They do not directly affect consumption, but indirectly they do – the greater the resistance of the exhaust route (many bends, a long route close to the limit), the more energy the boiler's fan must expend to overcome this resistance, and the sooner the boiler may reduce output or report a fault. Designing the route with the smallest necessary number of parts is therefore also advisable from the point of view of operating economy.

Warranty

This part of the ATTACK exhaust system is covered by a 24-month warranty from the date of dispatch from the warehouse, the same as other accessories for ATTACK condensing boilers. In the event of a claim, we recommend keeping the proof of purchase and, if necessary, photo documentation of the installation method, as with exhaust systems the functionality is closely linked to the correctness of the installation (observing the slope, maximum route length and clearances according to the manual).