Vaillant set – horizontal flue pipe 0.75 m + 87° elbow

Product detailed description

Vaillant assembly – horizontal flue pipe 0.75 m + 87° elbow – complete set for outlet through the facade

This assembly (code 0020219517) is a complete, pre-prepared combination of the two most commonly used components of the flue gas route for a horizontal flue pipe outlet of a condensing boiler through the external wall – a straight flue pipe section with a length of 0.75 m and an elbow with a direction change of 87°. This is a practical, cost-effective and installation-friendly solution for the most common method of installing Vaillant condensing boilers in family houses and apartments, where the boiler is located near the external wall and flue gases are led directly through the facade, not through the roof.

Why horizontal outlet through the facade is the most common solution

Horizontal routing of the flue gas path through the external wall is clearly the most frequently used solution in most residential and family house installations of condensing boilers, as the boiler is usually located in the kitchen, boiler room, utility room, or hallway near an external wall, and a short, direct route through the facade represents the simplest, least time-consuming and least costly option for flue gas discharge compared to vertical routing through the roof or connection to an existing chimney. This assembly is designed precisely for this type of installation, combining a straight section with the elbow needed to correctly direct the outlet outside the building.

Description of the assembly components

The straight flue pipe section with a length of 0.75 m serves to bridge the distance between the boiler outlet (or another route component) and the point of direction change or wall penetration. This length is one of the standard lengths offered by the manufacturer and, in practice, is often sufficient to bridge the typical distance between a wall-mounted boiler and the point of penetration through the external wall structure.

The elbow with an 87° direction change is the standard angle used when transitioning from a horizontal route outward through the wall, as the slight deviation from a right angle (90°) in the 87° type accounts for the necessary minimum slope of the route toward the outside of the building, which ensures that any condensate forming in the flue pipe drains outward, not back into the boiler, and that rainwater at the outdoor termination cannot leak into the pipe.

Typical uses of this assembly

• Outlet from the boiler directly through the nearest external wall – the most common scenario, where the boiler is located right next to the external wall and a short straight section and one elbow are enough to reach the facade,
• Change of route direction in the utility room – if the boiler is not mounted directly next to the external wall, the elbow allows the route direction to be changed so that it reaches the nearest suitable penetration point,
• Replacement of damaged parts during servicing – the assembly can also be used to replace existing, damaged, or outdated components as part of maintaining an older installation,
• New installations and renovations – the assembly is suitable both for new buildings, where the flue pipe route is designed from scratch, and for renovations, where an older heat source is being replaced with a condensing boiler with forced flue gas discharge.

Installation and technical principles

When installing this assembly, it is essential to maintain the minimum slope of the horizontal section toward the outside of the building (generally at least 3°, or the equivalent of approximately 5 cm per meter of length, exact value according to the manufacturer's technical documentation), which ensures that condensate formed during the operation of the condensing boiler does not accumulate in the pipe but flows smoothly back toward the boiler, where it is discharged through the condensate trap. An incorrectly, i.e., oppositely sloped section of the route could lead to condensate accumulating at a low point in the route, which in winter also poses a risk of freezing and blocking the flue pipe.

Another important aspect is ensuring the correct distance of the flue pipe outlet from windows, doors, ventilation openings, neighboring buildings, and sidewalks or public areas in accordance with applicable legislation and technical standards governing the placement of flue gas route outlets – these distances are set primarily with regard to safety (concentration of flue gases in the outdoor air near the outlet) and the comfort of the surroundings (noise, condensation mist from the outlet during operation).

Installation should be carried out by a professionally qualified person authorized to install gas appliances, who will also ensure proper mechanical anchoring of both components to the wall or ceiling structure to prevent undesirable bending or displacement of the joints.

Compatibility

This assembly is designed for concentric flue pipes with an outer diameter of 125 mm (typically 80/125 mm connection) used in most Vaillant condensing gas boilers of the ecoTEC, ecoTEC plus, ecoTEC exclusiv, and turboTEC series. Before ordering, we recommend verifying the exact flue pipe diameter used for a specific boiler model according to its technical documentation, as other diameter ranges also exist for other power categories.

Inspection access and future servicing

When designing a route with this assembly, it is worth considering whether it is necessary to add a separate inspection piece with an opening for checking and cleaning the inside of the pipe, or to choose a variant with an inspection elbow instead of the standard one, if the specific installation layout or the chimney sweep's requirements call for it. This standard (non-inspection) assembly does not include an inspection (control) opening, so for longer or more complex routes, we recommend adding a separate inspection element at a suitable point along the route.

Material and durability

Both components of the assembly are made from materials standardly used in the Vaillant flue pipe system – resistant to the acidic condensate formed during condensing operation, to weather effects at the outdoor, exterior end of the route (UV radiation, rain, frost), and to the operating temperatures of the flue gases. This durability guarantees long-term functionality and tightness of the assembly without the need for replacement throughout the expected service life of the boiler.

Why buy the assembly instead of separate parts

Buying the assembly instead of two separate components (the straight section and the elbow) brings the practical advantage of a single order number for the most commonly required combination of parts, which simplifies ordering for installation companies and end customers alike. At the same time, the assembly generally represents a slightly better price compared to the sum of the prices of individual parts purchased separately, as it is a standardized, frequently sold combination.

Frequently Asked Questions (FAQ)

Is this assembly enough for the entire flue pipe route from the boiler to the facade?
For boilers located right next to the external wall, this assembly may be sufficient for the entire route; for a greater distance between the boiler and the wall, additional extensions must be added according to the actual route length.

What is the difference between this assembly and an assembly with an inspection elbow?
This assembly includes a standard elbow without an opening for inspection, while an assembly with an inspection elbow allows access to the inside of the pipe for inspection and cleaning without having to dismantle the entire route.

Is a slope of the route needed even for such a short section as 0.75 m?
Yes, the minimum prescribed slope must be maintained regardless of the section length, as even a short horizontal section can retain condensate if the slope is incorrect.

Can I use this assembly for vertical routing through the roof as well?
This particular assembly is designed for horizontal routing through the facade; different components (roof penetrations, vertical extensions) are used for vertical routing through the roof, which are part of a separate product range.

How far from windows must the flue pipe outlet be located?
The exact clearance distances are set by the manufacturer's technical documentation and applicable technical standards; generally, these are minimum distances from windows, doors, and ventilation openings ranging from tens of centimeters to several meters, depending on the specific configuration – we recommend verifying this directly with the installation company or designer.

Can this assembly be used with multiple changes of route direction, i.e., with additional elbows?
Yes, the assembly represents a basic combination, to which additional elbows, extensions, or other components can be ordered as needed for a specific installation, if the layout of the route between the boiler and the facade requires it.

Summary

The Vaillant horizontal flue pipe assembly 0.75 m with an 87° elbow is a practical, standardized solution for the most common type of condensing boiler installation with flue gas discharge through the external wall. It combines a straight section and an elbow in a single order item, simplifying both installation and ordering for installation companies, while maintaining full compatibility and the quality of original Vaillant accessories.

Additional recommendations for choosing the wall penetration location

When choosing the location for penetration through the external wall, we recommend considering not only technical parameters (route length, number of elbows, clearance distances) but also practical aspects such as the visibility of the outlet from the street or from a neighbor's property, the direction of prevailing winds (which can affect how the condensation mist from the outlet disperses into the surroundings), and possible future developments in the surroundings of the building (for example, planned planting, an extension, or a change in the use of the adjacent land). These considerations are part of a comprehensive project design that should be addressed by an experienced designer or installation company together with the investor before the actual implementation.

Comparison with longer straight sections

In addition to the 0.75 m length, Vaillant also offers straight flue pipe sections in other standard lengths (for example, 0.5 m, 1.0 m, or 2.0 m) as part of its accessory range, which can be combined according to the exact distance between the boiler and the wall penetration point. The 0.75 m length featured in this assembly is a suitable compromise for medium distances, typical especially when the boiler is placed on a partition wall opposite the external wall or at a slightly greater distance from it than the shortest 0.5 m section would cover. For greater distances, the assembly must be supplemented with additional extensions purchased separately.

Why the elbow angle is 87°, not 90°

The choice of an 87° angle instead of the seemingly more natural right angle of 90° is not accidental – this slight deviation from a right angle ensures that the horizontal section of the route leading from this elbow outward from the building already has the minimum slope built in that is needed for proper condensate drainage, without the installer having to additionally tilt the entire route "by eye." This solution simplifies installation while ensuring that, even in a standard, typical installation, the slope of the route will meet the manufacturer's technical requirements for condensate drainage.

Practical experience with ordering this assembly

This particular combination of a straight section and an elbow is among the most frequently ordered Vaillant flue pipe accessory items precisely because it corresponds to the most common installation scenario – a boiler mounted on the wall in a utility room or kitchen with a relatively short distance to the nearest external wall. Installation companies therefore often order this assembly in larger quantities at once when carrying out multiple similar installations, for example when building terraced houses or apartment units with a similar utility room layout.

Relation to noise aspects of the outlet

When placing the flue pipe outlet on the facade, it is also worth considering the acoustic aspect – the operation of the condensing boiler's flue gas fan is generally quiet, but when the outlet is located very close to the windows of bedrooms or living areas, whether one's own or a neighbor's, it may be noticeable, especially at night when the ambient noise level is low. This consideration is part of a broader assessment of the suitability of a specific penetration location, which should take into account not only technical but also neighborly and comfort-related aspects.

Recommendations for winter operation

In outdoor climatic conditions with the occurrence of frost, it is important that the flue pipe outlet is not located where ice could form from condensate escaping from the outlet (for example, above a sidewalk or an entrance door, where frost could pose a slipping hazard). This consideration is part of a responsible design of the outlet's position, which should be taken into account by the installation company together with the investor already when planning the route, ideally before the final decision on the placement of sidewalks, terraces, and entrances around the house.

Relation to the building's energy certification

The placement of the flue pipe outlet on the facade can, in some cases, also affect the thermal assessment of the building's envelope, as penetration through the thermal insulation layer of the facade represents a potential thermal bridge if not properly resolved. Quality installation with an emphasis on proper sealing and possible additional insulation around the penetration can minimize this effect, which is particularly relevant for new buildings with high energy efficiency requirements.

Storage and handling before installation

Until installation, we recommend storing both components of the assembly in a dry environment protected from mechanical damage, especially in the area of the plug-in joints at both ends. During handling, it is advisable to avoid excessive mechanical stress on the elbow, which could cause micro-deformations affecting the later tightness of the joint with adjoining route components.

For transport to the construction site, we recommend transporting the components in their original manufacturer packaging, which is designed to protect the fittings from damage during normal handling and transport, and to unpack them only immediately before installation itself.

Relation to installation documentation for final building approval

During the final approval of a new building, or upon handover of the work after a renovation, it is common practice for the installation company or inspection technician to document the routing of the flue gas path, including the location of the outlet and compliance with clearance distances from surrounding structures. The use of original, certified Vaillant components, such as the parts of this assembly, facilitates this documentation, as the technical parameters of all components are clearly defined in the manufacturer's documentation and do not need to be additionally verified or justified before the inspection authority.

Summary of the main advantages of this assembly

In summary, this assembly offers a proven, standardized combination of the two most frequently needed components for a horizontal flue pipe outlet in a single order item, a built-in correct route slope thanks to the 87° elbow angle, full material resistance to condensate and weather effects, and simple, quick installation suitable for the most common scenario of placing a condensing boiler near an external wall, making it a practically standard part of most new installations and renovations with Vaillant condensing technology.