Vaillant · Heat-pump or fixed-AC model
aroTHERM plus
Vaillant aroTHERM plus is an R290 monobloc air-to-water range, with established UK models from 3.5 to 12 kW.
Specifications
| Specification | Value |
|---|---|
| Type | monobloc air-source, air-to-water heat pump |
| Product codes | established range uses VWL 35/6, 55/6, 75/6, 105/6 and 125/6 outdoor families |
| Rated output (kW) | 3.5, 5, 7, 10 and 12 manufacturer capacity classes |
| Supply phases | 230 V or 400 V depending on capacity and code |
| Refrigerant | R290 in the outdoor unit |
| Maximum flow temperature (°C) | 75 |
| Minimum operating temperature (°C) | -25 |
| Indoor options | uniTOWER, hydraulic station with uniSTOR cylinder or heat-pump interface |
| Warranty (years) | 2 standard; up to 7 subject to current installer, registration and Vaillant-cylinder conditions |
| MCS certified | current exact established-range records were present on 23 July 2026 |
aroTHERM plus is Vaillant’s R290 monobloc air-to-water heat pump. Its refrigerant circuit remains in the outdoor unit and water connects it to the indoor hydraulic equipment.
Established range and new generation
The established UK range lists 3.5, 5, 7, 10 and 12 kW classes. Its outdoor codes use VWL 35/6, 55/6, 75/6, 105/6 and 125/6. Vaillant also publishes a separate new-generation aroTHERM plus page. The complete VWL code and revision distinguish these products; a capacity and aroTHERM plus description do not.
The technical schedule includes 230 V and 400 V forms depending on size. Electrical supply, protection and hydraulic flow requirements therefore come from the exact model table.
Temperature limits and indoor options
Vaillant states flow temperatures up to 75°C and operation down to -25°C for the established R290 range. These are operating boundaries. Available output and efficiency at the project’s design outdoor temperature and flow temperature still need the exact performance data.
Indoor arrangements include uniTOWER with integrated hot-water storage, a hydraulic station with a separate uniSTOR cylinder and a heat-pump interface for more customised hydraulic layouts. The outdoor capacity and cylinder size are separate design choices.
Certification and guarantee record
The MCS (Microgeneration Certification Scheme) Product Directory contained current established VWL 35/6 to VWL 125/6 records on 23 July 2026. The 10 and 12 kW records found in that check had dated end points in October 2026, while smaller models displayed open-ended records. The exact live code should be checked for a project.
Vaillant states a two-year standard guarantee and a route up to seven years when the installer, registration and Vaillant-cylinder conditions are met. The issued certificate records the applicable term.
Related entries
Manufacturer and reference sources
Brand
Reference type
Heat-pump or fixed-AC model
Last reviewed
23 Jul 2026
Current status
Current in the manufacturer's UK range.