Product detailed description

Vaillant elbow 45°, Ø 110 mm

The 45° elbow is the most commonly used angled fitting wherever the route of the Ø 110 mm shaft flue needs to be diverted more significantly from a straight line – for example when transitioning from a vertical shaft into a connection position at the side or top of the boiler, or when bypassing a larger obstacle in the shaft.

Vaillant LAS Ø 110 mm shaft flue gas exhaust system

This part is part of the original Vaillant shaft flue gas exhaust system (abbreviated LAS – from the German "Luft-Abgas-System"), which is used with large-capacity condensing boilers (typically higher-output ecoTEC exclusiv/pro/plus series and ecoCRAFT exclusiv floor-standing boilers, as well as equivalent-output Protherm models from the same manufacturing group). Unlike a common concentric flue (pipe-in-pipe) used with small wall-mounted boilers, the shaft system carries flue gases through a single-wall pipe with a diameter of 110 mm inside an existing structural chimney shaft (most often an older masonry chimney no longer used for its original purpose), while combustion air is drawn in through the free space of the shaft around this pipe.

The advantage of this solution is that it requires no new penetration through the façade or roof in addition to the existing shaft, and in multi-storey buildings it allows the exhaust to be routed to the required height without the need to build a new chimney. All parts of the system are made of durable polypropylene (PP), which withstands long-term contact with the mildly acidic condensate produced during the operation of a condensing boiler, and are joined by a simple socket-to-socket push-fit system with an integrated sealing ring, without the need for gluing or additional sealing compound.

Why 45° is the most versatile angle

In the practice of designing flue gas exhausts, the 45° angle proves to be a good compromise between a sufficiently pronounced change of direction and maintaining favourable flue gas flow – a sharper bend (for example a full 90°) would in some systems increase resistance and the risk of condensate settling in the bend. Additionally, two 45° elbows connected by a short straight section can replace one 90° bend with more favourable flow characteristics.

This part is therefore usually the first choice for an installation company when dealing with any larger deviation of the route – finer adjustments are handled by the 15° or 30° elbow, while a full turn from vertical to horizontal uses the already mentioned 87° elbow (inspection or support type).

Installation and recommendations

Before final insertion, the elbow can be freely rotated around the axis of the pipe, allowing the direction of the 45° deviation to be aligned precisely according to the needs of the specific location. When using two 45° elbows instead of one sharper bend, make sure there is enough space in the shaft for the short connecting section between them.

Step-by-step installation procedure

1. Identify the point in the route design where a more pronounced deviation is needed (for example connecting to a boiler outside the direct axis of the shaft).
2. Before inserting, rotate the elbow to the required direction of deviation around the longitudinal axis of the pipe.
3. Apply a suitable lubricant for plastic systems to the sealing ring and push the elbow fully home.
4. If you plan to replace one sharp bend with a pair of 45° elbows, leave enough space between them for a short connecting section.
5. After insertion, check the correct orientation and continue connecting the rest of the assembly.

Practical example

When connecting a boiler positioned outside the direct axis of the shaft outlet (offset of approximately 40 cm to the side), instead of one sharp bend, a pair of 45° elbows was used with a short horizontal section between them, achieving a smooth lateral shift of the route to the boiler connection with more favourable flue gas flow than a single sharp bend.

How to choose between the 45° elbow and the 87° elbow

The 45° elbow is suitable when the route needs to be diverted significantly, but still within the original approximate orientation (for example tilting the route towards the side of the boiler), while a complete change of orientation from vertical to horizontal belongs to the 87° elbow (support or inspection type). If the planned change of direction exceeds 45°, it is usually more efficient and flow-favourable to use a single 87° elbow rather than a combination of several 45° pieces. We recommend preparing a simple sketch of the route with the angles marked at each point of direction change before ordering, to be sure of the correct choice of individual elbows.

When ordering, it is also worth considering that each 45° elbow adds two additional socket joints to the assembly (at both of its ends) compared to the originally planned straight section – when calculating the total number of sealing rings and the required assembly lubricant, therefore account for this extra item, especially if you plan to use several elbows in one assembly.

When to reach for the 45° elbow

• a more pronounced bypass of an obstacle (beam, protrusion, other piping) in the shaft cross-section,
• replacing one 90° bend with a pair of 45° elbows with more favourable flow,
• connecting the route to a boiler positioned outside the direct axis of the shaft.

Compatibility and use in the system

This part belongs to the closed range of original Vaillant accessories for the Ø 110 mm shaft flue exhaust and is designed to be combined with other parts from the same range – extensions (0.5 m, 1.0 m and 2.0 m), elbows of various angles, inspection pieces, the support elbow, spacer holders, mounting clamps and the wall rosette. It is used primarily when installing or replacing large-capacity condensing boilers from Vaillant (ecoTEC exclusiv, ecoTEC pro/plus higher-output versions and ecoCRAFT exclusiv floor-standing boilers), as well as corresponding Protherm models (Panther Condens, Tiger Condens, Bizon Condens in higher outputs) – Vaillant and Protherm belong to the same manufacturing group, so parts of the exhaust system are commonly identical, however always verify the exact type and size of the connection in the installation manual for the specific boiler.

Before ordering, we recommend having our customer service or an installation company prepare a simple assembly design according to the height and diameter of your existing shaft – the correct number and combination of parts (length of straight sections, number and angle of elbows, number of spacer holders and mounting clamps) is key for the safe and standards-compliant operation of the entire exhaust system.

Shaft flue gas exhausts of this type are designed and assessed in Slovakia and the Czech Republic according to the STN EN 1443 (Chimneys – General requirements) and STN EN 14471 (Chimneys – System chimneys with plastic flue liners) series of standards, which, among other things, define the designation of the so-called temperature, pressure and resistance classes of components (for example resistance class to condensate "W" – wet operation, typical precisely for condensing boilers). Original Vaillant parts of this range comply with the relevant classes stated in the manufacturer's documentation and the installation manual of the specific boiler with which the system is supplied – this compliance is exactly why it is recommended to use only parts from one closed range for a shaft flue exhaust, rather than combining them with products from other manufacturers.

Comparison with the 30° elbow and the support/inspection 87° elbow

The 45° elbow provides a more pronounced deviation than the 30° elbow, yet still more favourable flue gas flow than a sharp bend close to 90°. Where the route needs to be fully turned from vertical to horizontal, the 87° elbow (inspection or support type) is used instead – the 45° elbow is therefore typically an intermediate step or an alternative to one sharp bend in the form of a pair of elbows.

Technical parameters

Maintenance and service checks

The polypropylene shaft flue exhaust is low-maintenance, but as part of the flue gas path it is, like a masonry chimney, subject to regular inspection by a chimney sweep according to applicable regulations and intervals set by the boiler manufacturer and local chimney inspection regulations. During the inspection, the tightness of the joints, the patency of the pipe (deposits, possible foreign objects), the condition of the sealing rings in the socket joints, and the functionality of the condensate drainage from the lower part of the system are checked in particular. Parts made of PP are not usually cleaned with aggressive solvents – mechanical removal of deposits and rinsing with water, or a mild detergent, is sufficient.

The condensate produced during the operation of a condensing boiler is mildly acidic (typically in the range of pH approximately 3 to 5, depending on the type of gas being burned and the operating state of the boiler), therefore the entire route of the system is designed with a slope towards the collection point and condensate drainage either directly into the boiler (where it is usually neutralised or discharged into the sewage system via a siphon), or into a separate collection point at the base of the shaft. During regular inspection, therefore, also pay attention to whether the condensate is actually draining freely and not standing at lower points of the route, which could indicate an incorrect slope or a blockage in some section.

Safety notes

A standard, non-load-bearing part – correct orientation during installation is the only important factor, while anchoring the assembly to the wall itself is handled by the support elbow.

Why an original part and not a universal replacement

The angle and dimensions of the socket joints of the original elbow correspond exactly to the rest of the Ø 110 mm range and to the certification of the entire system – a universal replacement from a different product range may have different socket joint tolerances, which is not worth risking on a flue gas path.