Product detailed description

Vaillant inspection elbow 87°, Ø 110 mm

The inspection elbow with a bend of approximately 87° combines a change of direction of the route from vertical to horizontal with an integrated inspection (control and cleaning) opening directly at the bend – exactly where condensate and any deposits are most commonly trapped in flue gas discharge systems.

Vaillant LAS shaft flue gas discharge system Ø 110 mm

This component is part of the original Vaillant shaft flue gas discharge system (abbreviated LAS – from the German "Luft-Abgas-System"), used with large-capacity condensing boilers (typically the higher output ranges of ecoTEC exclusiv/pro/plus and floor-standing ecoCRAFT exclusiv boilers, as well as equivalent output models of Protherm from the same production group). Unlike a common concentric flue (pipe within a 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 facade or roof penetration in addition to the existing shaft, and in multi-storey buildings it allows the flue 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 slightly acidic condensate produced during operation of a condensing boiler, and are joined using a simple socket-to-socket push-fit system with an integrated sealing ring, without the need for gluing or additional sealing.

Difference from the support 87° elbow

It is important not to confuse this component with the support elbow 87° with a 350 mm mounting rail – while the support elbow is a load-bearing, wall-anchored component without an inspection opening, this inspection elbow, on the other hand, does not have a mounting rail and is not intended to bear the weight of the assembly; its purpose is solely to allow a change of direction with inspection access. In practice, the inspection elbow is therefore used, for example, higher up in the route (where a load-bearing function is no longer needed, but an additional inspection point is useful), while the support elbow handles exclusively the lowest, statically loaded point of the assembly.

The inspection opening is fitted with a sealing cover that can be repeatedly opened during inspections by a chimney sweep or service technician without having to dismantle the surrounding parts of the assembly.

Recommended placement

Install the component so that the inspection opening remains accessible after the construction work is completed (for example, through an inspection door in the shaft cladding). The orientation of the bend can be freely adjusted by rotating it around the pipe axis before insertion; the position of the inspection cover itself should face a space with actual access.

Step-by-step installation procedure

1. Choose a location in the route where the inspection opening will be accessible after the construction work is completed, and where a change of direction of the route is also needed.
2. Before inserting, rotate the elbow so that the inspection opening faces an accessible space.
3. Apply a suitable lubricant to the sealing ring and push the elbow fully into the adjacent part.
4. Verify that the inspection opening cover is properly closed after installation and easily accessible for future opening.
5. Record the position of the inspection elbow in the documentation for future chimney sweep inspections.

Practical example

In an assembly routed through three floors of an apartment building, where a support component was installed at the base of the shaft, the chimney sweep recommended at the first inspection adding another inspection access point at the height of the second floor, where the route also slightly changed direction while bypassing a structural partition wall. This is exactly where an 87° inspection elbow was used, which solved both the change of direction and the required inspection access with a single component, without the need for a separate straight inspection piece and another elbow next to it.

How to tell when to use an inspection elbow and when a support elbow

The key question when choosing between an inspection and a support 87° elbow is whether the given point in the assembly must bear the weight of the components above it (in which case always use the support elbow with a mounting rail), or whether it only needs a change of direction with possible inspection access (in which case use this inspection elbow). A single assembly typically uses exactly one support elbow (at the lowest, statically decisive point) and, as needed, one or more inspection elbows higher up in the route, wherever a change of direction and inspection access are both desired. If in doubt about which type of component a given location requires, it is always worth consulting the installation company before ordering.

Typical placement in the assembly

• a change of direction of the route on an intermediate floor or technical floor, where an additional inspection point is also desired,
• an additional inspection access point alongside the main support elbow at the base of the shaft,
• the upper part of the assembly before connecting to a chimney cap or shaft termination.

Compatibility and use in the system

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

Before ordering, we recommend having our customer service or an installation company prepare a simple assembly design based on 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 brackets and mounting clamps) is key to the safe and standards-compliant operation of the entire flue system.

Shaft flue gas discharge systems of this type are designed and assessed in both 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 class of components (for example, condensate resistance class "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 installation manual of the specific boiler with which the system is supplied – this compatibility is precisely why it is recommended to use only parts from a single closed range for a shaft flue discharge, rather than combining them with products from other manufacturers.

Comparison with the 87° support elbow

As mentioned above, this is a functionally different component from the support elbow with a mounting rail – this inspection elbow is not used for anchoring or bearing weight, but solely for changing the direction of the route with inspection access. Both components have a similar bend angle, but they perform completely different roles in the assembly, and one cannot replace the other.

Technical parameters

Maintenance and service inspections

The polypropylene shaft flue gas discharge is low-maintenance, but as part of the flue gas path it is, just 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 inspection, particular attention is paid to the tightness of the joints, the patency of the pipe (deposits, any foreign objects), the condition of the sealing rings in the push-fit joints, and the proper functioning of condensate drainage from the lower part of the system. Parts made of PP are generally not cleaned with aggressive solvents – mechanical removal of deposits and rinsing with water, or possibly a mild detergent, is sufficient.

The condensate produced during operation of a condensing boiler is slightly acidic (typically in the range of approximately pH 3 to 5, depending on the type of gas burned and the operating state of the boiler), so 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 actually drains freely and does not remain standing at lower points of the route, which could indicate an incorrect slope or a blockage in some section.

Safety and regulatory notes

The presence of a sufficient number of inspection/control access points along the height of the assembly is part of the requirements for safe operation and regular inspection of the flue gas path by a chimney sweep – this elbow is one of the common ways to add such access to the route.

Why have an inspection point besides the base of the shaft

Relying on just one inspection access point along the entire height of a multi-storey shaft can in practice mean that more distant sections of the route remain without actual inspection. An inspection elbow placed higher up in the route eliminates this risk without any need to compromise on the load-bearing function of the support elbow.