The Vaillant aroTHERM plus v2 is the next generation of Vaillant's flagship air source heat pump range, available here in the 3.5kW, 5kW and 7kW single-phase (230V) outputs, supplied without an interface (heat pump only – the VWZ AI control module, hydraulic module or uniTOWER indoor unit are ordered separately to suit the system design). Built around the natural refrigerant R290, this monobloc heat pump delivers flow temperatures of up to 75°C with a 10-year Global Warming Potential of just 0.02, while Vaillant's new Flexible Space Function significantly reduces the protection zone required around the unit for easier siting in space-restricted gardens, under windows, or next to doors.
Up to 75°C
Max Flow Temperature
44.1–44.3 dB(A)
Sound Power (3.5/5kW)
GWP 0.02
10-Year Global Warming Potential
A+++
Energy Efficiency Class (35°C)
Flexible Space Function
Vaillant's new safety concept significantly reduces the protection zone required around the heat pump, unlocking installation in tighter areas – under windows, next to doors, or in narrow side passages – that were previously off-limits. The function is activated in the installer settings.
Supplied Without Interface
This listing covers the heat pump unit only. A VWZ AI control module, hydraulic module, or uniTOWER pre-plumbed indoor unit must be selected separately depending on the system design – standard heating-only, heating with a separate cylinder, or an all-in-one indoor unit with integrated 190 litre cylinder.
RCD and Fuse Requirements
All Vaillant heat pumps must be installed with a Type B RCD rated to 20kHz or greater with a minimum trigger point of 150mA above 1kHz. These 230V models require a Type C, slow-blow, single-pole switching fuse rated to 16A.
Super Quiet Operation
The aroTHERM plus is the quietest air-to-water heat pump in Vaillant's portfolio, with sound power levels as low as 44.1dB(A) on the 3.5kW model and 44.3dB(A) on the 5kW model, giving an advantage when choosing the installation location.
High Flow Temperatures, Low GWP
R290 refrigerant enables flow temperatures of up to 75°C, while its 10-year GWP of just 0.02 makes it significantly more climate-friendly than the traditionally assumed value of 3 often quoted for R290 systems.
Up to 7-Year Extended Guarantee
The aroTHERM plus v2 comes with an extended guarantee of up to 7 years when registered with a Vaillant cylinder on myREWARDS, giving customers long-term system reliability and peace of mind.
Discreet Anthracite Casing
The new anthracite casing retains the distinctive look of its award-winning predecessor, blending in perfectly with UK housing stock and suiting retrofit installations.
Quiet Mark Certified
The aroTHERM plus range is Quiet Mark accredited, reflecting its position as one of the quietest air source heat pumps available.
Compact Standard Footprint
The 3.5kW and 5kW models share identical dimensions (765mm height), with the 7kW model only marginally taller (965mm), simplifying specification and installation planning.
Model Variants in This Range
| Output |
Vaillant Article Number |
Dimensions (H) |
Weight |
| 3.5kW |
8000049526 |
765mm |
114kg |
| 5kW |
8000049527 |
765mm |
114kg |
| 7kW |
8000049528 |
965mm |
132kg |
Technical Specification
| General |
| Dimensions (H x W x D) – 3.5kW/5kW |
765mm x 1100mm x 450mm |
| Dimensions (H x W x D) – 7kW |
965mm x 1100mm x 450mm |
| Weight, ready for operation – 3.5/5kW |
114kg |
| Weight, ready for operation – 7kW |
132kg |
| Heating Circuit Connection |
G 1¼" |
| IP Rating |
IPX4 |
| Electrical |
| Rated Voltage |
230V (+10%/-15%), 50Hz, 1~/N/PE |
| Rated Current, Maximum |
15.2A |
| Fuse Size |
16A |
| Fuse Type |
Characteristic C, slow-blow, single-pole switching |
| RCD Type |
Type B, rated to 20kHz or greater, min. trigger 150mA above 1kHz |
| Heating Circuit |
| Heating Water Temperature Range |
20°C to 75°C |
| Minimum / Maximum Volume Flow |
430 L/h / 860 L/h |
| Maximum Static Height Difference (outdoor to highest point) |
18m |
| Minimum / Maximum Operating Pressure |
0.5 bar / 2.5 bar |
| Water Volume in the Outdoor Unit |
1.5L |
| Refrigerant Circuit |
| Fluid Type |
R290 |
| Fluid Fill Quantity |
0.6kg |
| Global Warming Potential (GWP), 10-year |
0.02 |
| Compressor Type |
Rotary piston |
| Compressor Oil Type |
Specific polyalkylene glycol (PAG) |
| Noise & Efficiency |
| Sound Power Level, A7/W55 (ErP/outdoor) – 3.5kW |
44.1 dB(A) |
| Sound Power Level, A7/W55 (ErP/outdoor) – 5kW |
44.3 dB(A) |
| Sound Power Level, A7/W55 (ErP/outdoor) – 7kW |
46.8 dB(A) |
| Energy Efficiency Class, 35°C |
A+++ |
| Energy Efficiency Class, 55°C |
A++ |
Frequently Asked Questions
What does 'without Interface' mean for this heat pump?
It means the listing is for the outdoor heat pump unit only. The VWZ AI control module, hydraulic module, or uniTOWER indoor unit must be selected and ordered separately based on the intended system design.
What is the Flexible Space Function?
It's Vaillant's new safety concept for the v2 platform that significantly reduces the required protection zone around the heat pump once activated in the installer settings, allowing installation in tighter areas such as under windows, next to doors, or near basement shafts.
Why is the GWP figure so much lower than other R290 heat pumps?
R290 has a 10-year Global Warming Potential of 0.02, which is the figure Vaillant now quote for this range, rather than the traditionally assumed value of 3 (based on a 100-year GWP calculation) still commonly seen elsewhere.
Can these smaller models be wall mounted?
Vaillant wall mounting brackets are available as accessories for the aroTHERM plus range; confirm current compatibility for each specific output size with Vaillant or your distributor before ordering.
What flow temperature can this heat pump achieve?
Up to 75°C, allowing it to work effectively with existing radiator circuits in retrofit installations as well as underfloor heating and fan coil systems.
