Vaillant aroVAIR VA 2-3VW 070C – set with 3-way valve for 7 kW convector

Product detailed description

Vaillant aroVAIR VA 2-3VW 070C – 3-way switching valve kit for 7 kW fan coil units

Vaillant aroVAIR VA 2-3VW 070C (order number 0010035910) is a hydraulic add-on kit with a 3-way switching valve and the corresponding piping, designed for the most powerful console (under-window) fan coil in the Vaillant aroVAIR range – model VA 2-070/075 CN with an output of approximately 7.0–7.35 kW. The kit is an essential add-on for so-called two-pipe hydraulic connections, where a single shared pipe alternately supplies the unit with either hot water from the heat pump (in winter heating mode) or cold water (in summer cooling mode). Since the fan coil has only one heat exchanger connected to one circuit, something must ensure correct switching between these two modes at the source or distribution level – and that is exactly the purpose of the 3-way switching valve in this kit.

Without this kit (or an equivalent switching solution at the level of the entire heating/cooling system), a two-pipe connected fan coil would not be able to automatically respond to a signal from the room controller (for example VA 2-WC C or VA 2-WC D) and switch between heating and cooling – the valve is therefore a key hydraulic component that links electronic control with the physical flow of water in the system, and without it the unit would, in practice, receive only one type of water throughout the year, depending on how the rest of the system happens to be set.

The VA 2-3VW 070C kit is specifically sized for the flow and pressure parameters corresponding to the 7 kW output class – i.e. the largest unit in the VA 2 CN range. For smaller console units (VA 2-015 CN, VA 2-035 CN, VA 2-045 CN with outputs of 1.5 to 4.5 kW), the smaller sister kit VA 2-3VW C is used, which is sized for the lower flow rate corresponding to smaller heat exchangers.

Technical parameters

• Product type: kit with a 3-way switching (motorised) valve including connecting piping
• Intended for: Vaillant aroVAIR VA 2-070 CN / VA 2-075 CN (output approx. 7.0–7.35 kW)
• Valve function: controlled switching of water flow between the heating and cooling circuit in a two-pipe connection
• Valve control: electric, controlled by a signal from the room controller (e.g. VA 2-WC C, VA 2-WC D) or a higher-level control system
• Kit contents: 3-way valve with actuator + necessary connecting piping/fittings for connection to the VA 2-070 CN unit
• Compatibility: exclusively with the Vaillant aroVAIR VA 2-070/075 CN console unit (not with smaller models in the range, for which the VA 2-3VW C kit is used)
• Connection type: two-pipe hydraulic system with alternating hot/cold water flow
• Valve body material: brass/compatible metal and plastic components resistant to the operating media of heating/cooling circuits
• Installation: on the fan coil supply pipe, within reach of the electrical connection to the control system
• Country of origin: Germany / EU (manufactured within the Vaillant Group)
• Warranty: 2 years

Why a 3-way valve is needed specifically for two-pipe connections

Air-to-water heat pump heating and cooling systems can be connected to fan coils in two basic ways:

• Four-pipe system – the unit has a separate pipe for heating and a separate one for cooling (or possibly two separate heat exchangers), so nothing needs to be switched – both circuits can theoretically be available at the same time.
• Two-pipe system – the unit has only one circuit (one supply and one return), through which hot water flows in winter and cold water in summer. Switching between modes takes place either at the level of the entire heat/cooling source for the whole house, or locally at the unit using a motorised 3-way valve such as the VA 2-3VW 070C.

Local switching directly at the fan coil (instead of switching at the level of the entire system) is particularly advantageous where a given unit has different mode requirements than the rest of the house – for example a south-facing room that needs cooling sooner than the rest of the house's heating system switches to cooling mode, or conversely a room that needs additional heating even when the rest of the house is already in summer mode.

Installation and connection

Installation of the VA 2-3VW 070C kit consists of two steps – hydraulic and electrical:

• Hydraulic connection: the 3-way valve is fitted into the supply pipe leading to the heat exchanger of the VA 2-070 CN unit, using the supplied connecting elements and fittings corresponding to the connection dimensions of the given unit. The correct flow direction according to the marking on the valve body must be observed.
• Electrical connection: the valve actuator is connected to the control system (room controller or higher-level automation), which sends a signal to switch the valve position based on the required mode (Heating/Cooling selected on the VA 2-WC C or VA 2-WC D controller, or automatically for a model with an Auto function).

Installation and connection of this kit must be carried out by a qualified technician authorised to install heating and cooling equipment, in accordance with the Vaillant installation manual for the VA 2-070 CN unit and the given valve kit. After installation, a functional test must be carried out – to verify that the valve actually switches when the mode is changed on the controller and that there are no leaks at the joints.

Before commissioning, we also recommend bleeding the relevant pipe branch to ensure no air remains in the system, which could cause noise or reduced heat exchanger output.

Compatibility – do not confuse with the smaller kit

Important note when ordering: the VA 2-3VW 070C kit is designed exclusively for the largest console unit in the range – VA 2-070/075 CN (7.0–7.35 kW). For smaller units in the same range (VA 2-015 CN, VA 2-035 CN, VA 2-045 CN, i.e. outputs of 1.5 to 4.5 kW), the smaller sister kit VA 2-3VW C must be used, which is sized for a different (lower) flow rate and may not be mechanically or hydraulically interchangeable with the kit for the 7 kW unit. Before ordering, always check the exact designation of your fan coil on the unit's type plate, which is usually located on the inner side of the unit's casing or in the documentation supplied with the fan coil.

When you need the kit and when you don't

• You need it if your VA 2-070 CN fan coil is connected to a two-pipe system where switching between heating and cooling takes place directly at the unit (for example because the room with the fan coil has a different heating/cooling schedule than the rest of the house, or because switching is meant to happen automatically according to the room controller without intervention at the central source).
• You don't need it if the system is designed as a four-pipe system (separate heating and cooling branches) or if switching between modes is carried out centrally at the level of the entire heating/cooling source for the whole house, meaning the fan coil always receives the "correct" type of water for the current season.

Maintenance and care

The 3-way valve is a hydraulic component with moving parts (switching mechanism, seals), so more frequent inspection is recommended compared to purely electronic components:

• At least once a year, ideally at the transition between the heating and cooling season, visually check the tightness of the valve joints and adjacent piping.
• Verify that the valve actually mechanically shifts position when the mode is changed on the controller (an audible click of the actuator or a change in outlet pipe temperature according to the current mode).
• In case of leaks, unusual sounds during switching, or a situation where the unit does not respond to a mode change despite correct controller settings, contact a service technician – do not attempt to service the valve yourself without appropriate qualification.
• During extended shutdown of the system (e.g. outside both the heating and cooling seasons), no special action is required, but before restarting at the beginning of the season we always recommend performing a functional switching test.

The role of two-pipe systems in larger installations

Two-pipe connection with local switching using the VA 2-3VW 070C kit is often chosen in practice for larger family houses, where the VA 2-070 CN fan coil is most commonly installed in a large open living area (a living room connected to the kitchen, or several rooms connected to one hydraulic circuit). It is precisely in such spaces that the need for cooling in summer and supplementary heating during transitional months is most pronounced – large glazed areas and an open layout cause faster overheating in summer, while in winter additional heat may be needed alongside the main heating system (for example underfloor heating, which has higher thermal inertia and responds more slowly to sudden temperature changes caused by, for example, a larger number of people in the room or direct sunlight).

In such larger or zone-controlled installations, it makes sense for the most powerful fan coil in the range (VA 2-070 CN) to have its own local option for switching between heating and cooling independently of the rest of the house – which is exactly what this kit enables in combination with a suitable room controller.

Relation to output and water flow

The heat exchanger of the VA 2-070 CN unit operates with a significantly higher water flow rate than the smaller models in the range (VA 2-015/035/045 CN), since it must deliver approximately 7.0–7.35 kW of heating or cooling output. This is precisely why the 3-way valve in the VA 2-3VW 070C kit is sized for a different (higher) flow rate than the valve in the smaller VA 2-3VW C kit – using an incorrectly sized valve could cause either an unnecessarily high pressure drop in the circuit (and thus noise or increased load on the circulation pump), or, conversely, insufficient flow and a reduction in the unit's actual output compared to the catalogue value. Using the correct kit for the specific fan coil model is therefore important not only in terms of mechanical connection compatibility, but also in terms of the actual achievable output of the unit.

Why buy from us

We offer the Vaillant VA 2-3VW 070C kit as original accessory equipment directly compatible with the aroVAIR VA 2-070 CN console unit, with a 2-year warranty. If you are unsure whether your installation requires this specific kit, or the smaller VA 2-3VW C variant for lower output ranges, or whether your system needs a 3-way valve at all (this depends on whether the connection is single-pipe/four-pipe or two-pipe), we are happy to advise you before ordering based on the specific type of your fan coil and hydraulic connection scheme. We recommend combining this kit with a suitable room controller (VA 2-WC C or VA 2-WC D) and, for freestanding installations, also with VAZ-015-070-F1 feet, which can be found in the same accessories category.

Frequently asked questions