Vaillant Flue Extension 2.0 m, Ø 160 mm

Product detailed description

Flue Extension 2.0 m Ø 160 mm – the longest module with a minimum of joints

The two-metre extension is the longest module in the range (0.5 m, 1.0 m, 2.0 m) and is used mainly on longer straight sections of the route, where it is advantageous in terms of tightness and ease of installation to use as few socket joints as possible – each joint represents a potential (although minimal when correctly installed) point of flow resistance and must be checked during service inspections in the same way as the rest of the route.

The 2-metre module is typically used when routing a vertical riser through a multi-storey building, or for longer horizontal sections between the boiler room and a more distant outlet point (façade or roof penetration, connection to an existing chimney).

Flue exhaust systems for Vaillant cascade boiler rooms

When a single condensing boiler is not sufficient to cover the heat demand of a building – an apartment building, hotel, operational hall, office building or a larger technological boiler room – this is usually solved not by one large boiler, but by a cascade of several smaller or medium-output Vaillant condensing boilers connected in parallel. The advantage of a cascade solution is higher operational reliability (the failure of one boiler does not mean a heating outage for the whole building), better output control according to current demand (the number of running boilers and the output of each is modulated), and easier future expansion of the boiler room with an additional boiler if heat demand increases.

Each boiler in the cascade has its own port for flue gas exhaust and combustion air intake, but for practical, economic and structural reasons, the flue gases of all boilers are usually led out through one common collecting flue (collector) into a single chimney or through a single roof/façade penetration. This is exactly the purpose of the range of components described below – these are parts of a separate (non-concentric) flue gas exhaust system with a diameter of 160 mm or 200 mm, which connects to the ports of individual boilers and joins them into one common pipe.

The system is modular – it consists of basic connection sets (for the first two boilers of the cascade, including the necessary fitting for condensate drainage), extension sets (for each additional boiler added to the cascade), individual elbows of various angles for avoiding obstacles and changing the direction of the route, extensions of various lengths for bridging the distance between the boilers and the riser, and finally a set for connecting the whole assembly to a masonry chimney shaft.

Use in the assembly

The 2.0 m extension is particularly useful for longer straight sections of a vertical riser routed through several floors or a technical shaft, or for longer horizontal runs in more spacious boiler rooms, where a greater distance needs to be bridged with a minimum number of joints and thus a minimum number of potential leak points.

The part is fully compatible with the other components of the Ø 160 mm range and connects with the same socket joint with a sealing ring as the shorter variants.

Material and construction – why polypropylene (PP)

All parts of this range are made of polypropylene (PP) – a plastic used in the flue exhaust systems of condensing boilers precisely because it withstands perfectly the chemically aggressive condensate that naturally forms during the operation of condensing technology. Compared to a classic (non-condensing) boiler, a condensing boiler also uses the latent heat contained in the water vapour of the flue gases – this is cooled below the dew point in the flue gas heat exchanger and condenses, and the resulting condensate is mildly acidic (pH approximately 3–5, depending on the type of fuel and operating conditions). Metal (e.g. stainless steel) flues can also withstand this load, but plastic PP systems are lighter to handle, faster to install thanks to sealing-ring joints without the need for welding or special tools, and, at comparable quality, are usually also more cost-effective.

The operating temperature of flue gases in condensing boilers is relatively low (roughly up to about 80–120 °C, depending on the operating mode and output of the boiler) – this is precisely why the use of plastic PP piping instead of a classic metal flue (common, for example, in older atmospheric or low-temperature boilers) is not only possible, but also more suitable in terms of resistance to condensate. The system is certified and dimensioned by the manufacturer directly for use with Vaillant condensing boilers of the corresponding output range and port designation.

The joints between the individual parts are made using a socket connection with a rubber sealing ring (a so-called socket joint) – this design allows simple, tight, yet detachable installation without gluing or welding, which significantly simplifies any future modifications to the route, replacement of a damaged part, or expansion of the cascade with an additional boiler.

Practical example

In a boiler room located in the basement of an office building, from where the cascade's collecting pipe runs through a vertical shaft up to the roof (for example, through 5–6 floors), a combination of several 2-metre extensions is used – significantly reducing the total number of joints on the long riser compared to a solution made up exclusively of shorter, 0.5 or 1-metre pieces, which also simplifies the subsequent inspection of the route's tightness during revision.

Comparison of available lengths of Ø 160 mm extensions

The two-metre extension is the longest module in the range (0.5 m, 1.0 m, 2.0 m) and is particularly worthwhile on longer straight sections, where a smaller number of longer parts means fewer socket joints on the route – and thus fewer potential points that need to be checked during revision. For shorter distances or in confined spaces where handling a 2-metre piece would be impractical, shorter modules (0.5 m or 1.0 m) are recommended instead.

Ordering: When ordering for long vertical risers (for example, through several floors of a building), we recommend using this longest module as the main building block of the route, supplemented by shorter pieces only for precise adjustment to revision points or connections.

Assembly and installation

The installation of a flue gas exhaust system for gas appliances (including cascade boiler rooms) in Slovakia is subject to the requirements of the standards STN EN 1443 (Chimneys), STN 73 4201 (Chimneys and flues) and related gas industry technical rules (TPP), and must be carried out by an authorised and professionally qualified person – an authorised service technician or installation company with the relevant authorisation to install gas appliances and their flue exhaust systems. Commissioning the boiler room also includes an inspection of the chimney/flue carried out by a chimney sweep company and the issuance of the relevant inspection report.

When designing the route of a cascade flue, it is necessary to take into account in particular: the total rated heat output of all boilers in the cascade (this determines the required diameter of the collector pipe – 160 mm or 200 mm), the maximum permissible length of the route and number of elbows (the manufacturer states equivalent lengths for individual fittings), the slope of horizontal sections back towards the boiler or the condensate separator (generally at least 3° so that condensate can drain by gravity and does not remain standing in the pipe), sufficient fastening of the pipe with spacer brackets at regular intervals (typically every 1–1.5 m) to prevent sagging or excessive stress on the socket joints, and maintaining access to inspection openings and inspection elbows for regular cleaning and checking of patency.

When connecting several boilers in a cascade to a single collector pipe, it is also essential to respect the order and direction of feed of individual branches according to the manufacturer's installation instructions (including the recommended use of check flaps in cascades with three or more boilers, so that when one boiler is shut down, flue gases from running boilers do not flow back into the shut-down unit) and to maintain the prescribed minimum rise and direction towards the common chimney or façade/roof outlet.

Care of the extension during operation

For the two-metre extension, it is particularly important to fasten it thoroughly with spacer brackets along the entire length of the section (typically at least at two points) to prevent sagging under its own weight, especially with horizontal routing. During the annual inspection, the maintenance of the prescribed slope and the strength of these brackets are checked, together with the tightness of the socket joints at both ends.

Storage and handling before installation

The two-metre section is the longest and bulkiest part in the range of extensions, so it requires the most space and care during transport and storage – we recommend transporting and storing it lying flat, supported along its entire length, to prevent sagging or permanent deformation before installation. Handling it with several people at once (given its length) also reduces the risk of damage to the socket ends with sealing rings when carrying it to the installation site.

Service, cleaning and service life

Regular inspection and cleaning of the flue exhaust system is part of the standard annual service inspection of a condensing boiler room. Thanks to the inspection openings and inspection elbows in the assembly, individual sections of the pipe can be checked and, if necessary, cleaned (e.g. of any deposits) without the need for complete disassembly of the entire route. If included in the assembly, the condensate separator must be regularly checked and, if necessary, emptied/flushed to prevent it from clogging and condensate backing up into the pipe.

The service life of a quality PP flue exhaust system from the manufacturer, directly compatible with the given boiler range, is comparable to the service life of the boiler itself when properly installed and regularly serviced – that is, roughly 15 years or more of operation. When replacing or adding individual parts in the future (for example, when expanding the cascade with an additional boiler), it is advisable to use original components of the same manufacturer and diameter to maintain full joint compatibility and the validity of the warranty on the entire flue exhaust system.

Frequently asked questions

Why buy this Vaillant accessory at ATRIA.SK

We recommend the 2.0 m Ø 160 mm flue extension for longer straight sections of the route, where you will appreciate the lower number of joints and the simplified future inspection of the tightness of the whole assembly.

When purchasing any part of the flue exhaust system, we are happy to advise you on choosing the right combination of components for your specific boiler room – just contact us with details about the type and number of boilers, or with project documentation. We usually dispatch goods within 24–48 hours of ordering, and for larger assemblies we will inform you in advance of the delivery date if necessary.