Vaillant – pump groups and accessories

Pump Groups and Manifolds Vaillant for Multi-Circuit Heating

In this category you will find genuine Vaillant accessories designed for professional installation of multi-circuit heating systems connected to ecoTEC plus and pro condensing boilers – highly efficient electronic pump groups from the VDM series (direct and mixing), dual-circuit manifolds with a built-in hydraulic separator (low-loss header) of the WHV type, standalone hydraulic separators from the WH series for separating the boiler and heating circuits, as well as supplementary installation and service material – spacer frames for wall-mounted boilers and cylinders, condensate drain siphons, circulation pumps for indirectly heated VIH R uniSTOR cylinders, and replacement softening granulate.

Why solve the heating circuit with a pump group

In houses and facilities with multiple heating circuits (for example a combination of radiators and underfloor heating, or two circuits with different temperatures), it is not possible to connect all circuits directly to the boiler – each circuit requires its own circulation pump, and in the case of a lower-temperature circuit, also a three-way mixing valve that blends cooler return water with the boiler outlet. The VDM pump group integrates these functions into a compact, thermally insulated block with a 120 mm mounting spacing, which can be easily connected to a manifold or low-loss header.

Frequently Asked Questions

• What is the difference between a direct and a mixing VDM pump group? The direct group (VDM 10) contains only a circulation pump and is used for a circuit with the same temperature as the boiler circuit (typically radiators). The mixing group (VDM 20 M, VDM 25 M) additionally contains a three-way mixing valve with an actuator, which regulates the temperature of the lower-temperature circuit, for example underfloor heating.
• What is the purpose of a hydraulic separator (low-loss header)? It hydraulically separates the flow of the boiler circuit from the flow of the heating circuits, so that changes in flow on the heating side (e.g. closing of thermostatic heads) do not affect the operation of the boiler. It also allows easy connection of multiple pump groups.
• When do I need a dual-circuit manifold WHV instead of a standalone low-loss header WH? The WHV combines a low-loss header with a manifold for two circuits in one compact body with a 120 mm spacing, saving both space and installation time compared to assembling separate components.
• Is installation by an authorized technician required? Yes, connecting pump groups and manifolds is part of the hydraulic scheme of the heating system and should always be carried out or at least checked by a heating company experienced with Vaillant condensing boilers, in order to maintain the boiler warranty.
• Can this accessory be used with boilers other than Vaillant? Hydraulically yes, these are standard components with common threaded connections, but in terms of design and installation they are adapted for cooperation with Vaillant ecoTEC wall-mounted boilers.

What to pay attention to when choosing

When choosing a pump group or manifold, take into account primarily the required flow rate (m3/h) and the connection size (Rp), which must correspond to the heating output of the given circuit, as well as the 120 mm spacing, which is the standard for direct connection of multiple groups on a common low-loss header or manifold. For cylinder solutions (VIH R uniSTOR, VIH Q), also pay attention to the spacer frames, which ensure the correct safe distance between the boiler and the cylinder when installed side by side.