Vaillant aroTHERM plus VWL 75/8.1 A

Compatibility

External Edge monitoring not yet verified

The outdoor installation manual specifies a two-wire A/B communication link to the Vaillant indoor unit, not a spare third-party port. It separately depicts the indoor/system-regulator eBUS path. Vaillant promotes myVAILLANT connect and EEBUS for compatible system-level energy management, but the retained sources do not define a VWL 75/8.1 A BMS/Modbus point map, external read credentials, or safe Edge control contract.

Confirm article 8000033711, indoor unit (VIH QW 190/7, VWZ MEH 97/7 or VWZ AI /7 230V), system regulator, myVAILLANT gateway, software, country and hydraulic design. Keep the outdoor A/B link under Vaillant control. Obtain a current Vaillant-approved system-level EEBUS or other building interface contract and point/permission list before Edge monitoring; treat compressor, hot-water, EVU and grid-flexibility commands as separate commissioned functions.

Models

Specifications

The exact outdoor unit is a 230 V R290 monobloc in Vaillant's 35/55/75/8.1 manual, article 8000033711 for AT, CH and DE. The manual calls it a domestic outdoor heat-pump unit and requires a permitted indoor partner. It is not a stand-alone commercial BMS controller.²

Exact article and markets

VWL 75/8.1 A 230V, 8000033711; Austria, Switzerland, Germany²

A−7/W35 performance

6.94 kW heating output / 2.36 kW electrical input; COP 2.94 at the stated test point³

Compressor supply

230 V, 50 Hz; installed circuit and EVU arrangement require qualified design^2, 3

Refrigerant

R290, 0.9 kg in the VWL 75/8.1 product table³

Outdoor to indoor communication

Two-wire A/B link marked Modbus in the appliance diagram, 50 m maximum; internal Vaillant system connection²

System regulator link

eBUS from the indoor unit to a Vaillant system regulator in the manual's typical arrangement²

Dimensions and mass

965 × 1100 × 450 mm (H × W × D), 130 kg³

Sound power

57.4 dB(A) day / 46.2 dB(A) night in the July product table; siting rules still apply³

Interface

Documented measurements and integration boundaries for aroTHERM plus VWL 75/8.1 A.

• The current installation manual's validity table binds VWL 75/8.1 A 230V to article 8000033711 in Austria, Switzerland and Germany. Check that article number rather than the broad aroTHERM plus name, which also covers 400 V and S3 variants.
• Vaillant's system drawing separates the outdoor unit, a two-wire communication cable, the indoor unit, an eBUS cable and the system regulator. The outdoor board drawing labels the A/B link 'Modbus' and section 7.8 instructs a direct A-to-A, B-to-B indoor/outdoor connection of no more than 50 m. That is an internal appliance link, not evidence of an open BMS slave register map.
• The March manual permits the outdoor unit with specified VIH QW 190/7, VWZ MEH 97/7 or VWZ AI /7 230V indoor arrangements. It names the indoor regulator and system regulator separately. Confirm the actual hydraulic and controller topology before selecting any external interface.
• Vaillant's July product sheet states 6.94 kW heat output and 2.36 kW electrical input at A−7/W35 for this model (COP 2.94). These are test-point values, not a guaranteed whole-building load or measured seasonal performance. Meter electrical input and delivered heat separately if a site performance claim matters.
• The product page and interface overview describe sensoCOMFORT, myVAILLANT connect and EEBUS energy-management options. Vaillant's own exact-model case study shows VWZ MEH 97/7, sensoCOMFORT 720 and VR 940f on one installation. Neither a gateway nor EEBUS marketing establishes an unauthenticated local BMS/Modbus read path or permission for an Edge dispatch.
• The installation manual addresses EVU supply interruption and S21 on the indoor unit. A utility blocking input and EEBUS energy-management option have different safety and comfort implications. Do not inject controls into the refrigerant, defrost or domestic hot-water cycle without Vaillant-approved system engineering.

Setup

1. Identify the exact heat-pump system

   Record outdoor article 8000033711, indoor unit, system regulator, gateway and software versions. The Vaillant name on the outdoor case does not identify which indoor controls or internet module are installed.

2. Preserve the appliance link

   Trace the outdoor A/B cable to its Vaillant indoor unit. Section 7.8 specifies the pair, polarity and 50 m limit; do not attach Edge or another bus master to this internal connection.

3. Map approved system interfaces

   Determine whether the site has sensoCOMFORT, myVAILLANT connect VR 940f and an eligible EEBUS energy-management function. Obtain Vaillant's current compatibility and approved point/permission contract for the installed software, not a generic eBUS or Modbus claim.

4. Meter heat and electricity separately

   Define the heat meter boundaries and electrical supply, including auxiliary heaters and circulation pumps. A product-table COP at A−7/W35 cannot replace measured seasonal performance or a grid-point flexibility measurement.

5. Qualify any flexibility instruction

   Agree comfort, frost protection, hot water, defrost, EVU blocking and failsafe limits with the heating installer and operator before considering a controlled demand response interface.

Common questions

Does the outdoor unit have a Modbus port for a BMS?

The installation drawing labels the outdoor A/B link Modbus, but section 7.8 connects it directly to the Vaillant indoor unit and limits the cable to 50 m. The retained manual provides no third-party register list or permission to share that appliance link.²

Is VWZ AI /7 a Modbus gateway?

The manual lists VWZ AI /7 230V as a permitted indoor control arrangement and shows eBUS between the indoor unit and system regulator. It does not establish a generic BMS Modbus service on VWZ AI.²

Can myVAILLANT connect or EEBUS make this unit Edge-ready?

Vaillant describes myVAILLANT connect and EEBUS for system-level smart energy functions. One exact-model Vaillant case study uses a sensoCOMFORT 720 and VR 940f. The available sources do not specify an Edge reader, an exact point list or dispatch permission for this installed combination; obtain Vaillant's current eligibility and interface documents.^1, 4, 5

Can a utility signal safely turn off the heat pump for flexibility?

The manual discusses EVU blocking and indoor-unit S21 as installation choices, but does not grant third-party control authority. The heating-system owner must approve frost, hot-water, comfort and restart behaviour before any site-specific response design.²