The Vaillant Heat Pump Control Module Interface (VWZ AI) is the standard appliance-level controller for the Vaillant aroTHERM plus v2 heat pump range, designed to be installed directly with the outdoor unit to manage heating and domestic hot water generation. The unit features a digital display and soft-key control panel that shows the daily environmental energy yield, current operating mode, and system fault or maintenance messages at a glance, with menu-driven access to operating hours, filling pressure, and set-point adjustments.
174 x 272 x 52mm
Dimensions
Digital
Daily Energy Yield Display
2
Soft-Key Selection Buttons
0.1–0.15 MPa
Normal Filling Pressure Range
70°C
Max Cylinder Temp (Compressor)
8000044872
Vaillant Product Code
Compatible With aroTHERM plus v2 (VWL ..5/6 A)
The VWZ AI is intended for use exclusively with the VWL ..5/6 A outdoor heat pump unit range as its heat pump control module, in conjunction with an optional system control such as the sensoCOMFORT for full time-programme and multi-zone functionality.
Legionella Protection Requires Correct Set Points
Legionella bacteria multiply at temperatures below 60°C. Where no system control is connected, Vaillant specify a target cylinder temperature of 65°C with the electric back-up heater enabled for domestic hot water, to reliably achieve 60°C at outdoor temperatures below -10°C or above +30°C. Do not set water temperatures below 60°C without consulting a competent person first.
Time-Programmed Anti-Legionella Requires a System Control
The anti-legionella function's time programme is only available when a system control is connected. Without one, the target cylinder temperature must be set higher (65°C) to compensate, as no scheduled anti-legionella cycle can run from the VWZ AI alone.
At-a-Glance Energy Yield Display
The central display shows the daily environmental energy yield directly on the basic screen, giving installers and homeowners immediate visibility of system performance without navigating menus.
Built-In Safety Devices
Includes frost protection, low-water pressure protection, freeze protection (activating the compressor if heating flow temperature drops below 4°C), and pump blocking protection that exercises idle pumps every 23 hours.
Digital Filling Pressure Monitoring
A built-in pressure sensor continuously monitors the heating installation's filling pressure, displaying it digitally and raising fault message F.22 if pressure falls below 0.05 MPa (0.5 bar) for more than one minute.
Retrofit-Friendly Design
Designed to be seamlessly retrofitted into existing Vaillant aroTHERM installations, simplifying control upgrades without requiring a full system controller replacement.
Two Operating Levels
Separates the end-user operating level (essential information and basic set points) from a code-protected competent-person level reserved for installer configuration and diagnostics.
Detailed Operating Statistics
Displays total operating hours broken down by heating mode, domestic hot water mode, and cooling mode, supporting maintenance planning and performance tracking over the system's lifetime.
Technical Specification
| Product Identification |
| Product Name |
VWZ AI Heat Pump Appliance Interface |
| Vaillant Product Code |
8000044872 |
| Compatible Heat Pump Range |
aroTHERM plus v2 (VWL ..5/6 A outdoor units) |
| Physical |
| Dimensions (H x W x D) |
174mm x 272mm x 52mm |
| Installation Location |
Dry rooms only – moisture may damage the electronics |
| Control & Display |
| Display Type |
Digital display with soft-key selection buttons |
| Basic Display Timeout |
Backlight switches off after 1 minute of inactivity |
| Menu Timeout |
Returns to basic display after 15 minutes of inactivity |
| Reset Function |
Dedicated reset button on control panel |
| Operating Parameters |
| Normal Filling Pressure Range (cold) |
0.1 MPa to 0.15 MPa (1.0 to 1.5 bar) |
| Low Pressure Warning (M32) |
Below 0.07 MPa (0.7 bar) |
| Low Pressure Fault (F.22) |
Below 0.05 MPa (0.5 bar) for over 1 minute |
| Freeze Protection Trigger |
Heating flow temperature below 4°C |
| Pump Blocking Protection Interval |
Every 23 hours of inactivity |
| Max Cylinder Temperature (compressor only) |
Up to 70°C, depending on environmental energy source |
Frequently Asked Questions
Which heat pumps is the VWZ AI compatible with?
The VWZ AI is designed for use with the Vaillant aroTHERM plus v2 outdoor units in the VWL ..5/6 A range, as specified in Vaillant's own system installation instructions.
Does the VWZ AI include a system controller for multiple heating zones?
No. The VWZ AI is the heat pump appliance interface, providing essential display, monitoring and basic set-point control at the heat pump itself. For time programmes, multi-zone control and full anti-legionella scheduling, an additional system control (such as a sensoCOMFORT) should be connected.
What happens if no system control is connected?
Without a system control, the anti-legionella function's time programme is unavailable, so Vaillant recommend setting the target cylinder temperature to 65°C (with the electric back-up heater enabled) to maintain adequate legionella protection instead.
How do I check the heating system's filling pressure?
The current filling pressure can be viewed via Menu → Live Monitor → Building circuit pressure directly on the VWZ AI display.
What does fault code F.22 mean?
F.22 indicates the heating installation's filling pressure has fallen below 0.05 MPa (0.5 bar) for more than one minute. A competent person should investigate and top up the system as required.
