aroSTOR VWL B 270/5 UK
270 Litres
R290 Refrigerant
Energy Class A+
COP 3.14
52 dB(A)
🌿
R290 Refrigerant
GWP 3 · Zero ODP
⚡
Energy Class A+
COP 3.14 (EN16147)
🌡️
Up to 60°C
Heat pump only
⏱️
~10h 15m Heat-Up
From cold at A7
💧
349L Usable
DHW at 54°C
🔇
52 dB(A)
Sound power level
🛡️
Stainless Steel
5-year tank warranty
☀️
PV Ready
Solar integration
Vaillant aroSTOR VWL B 270/5 UK — 270L Integrated Heat Pump Water Heater — 270L stainless steel unvented cylinder with integrated air-source heat pump | R290 refrigerant (GWP 3, ODP 0) | Energy Class A+ | COP 3.14 (EN16147) | Up to 60°C (HP) · 65°C (HP + backup) | Heat-up ~10h 15m from cold | 349L usable DHW at 54°C | 1.2kW titanium backup | Ambient -7°C to +35°C | 52 dB(A) sound power | Article No: 0010028218
The Vaillant aroSTOR VWL B 270/5 UK is a self-contained, floor-standing integrated heat pump water heater combining a 270-litre stainless steel unvented cylinder with an air-source heat pump unit — all in one compact column. There is no separate outdoor unit, no additional cylinder and no connecting refrigerant pipework required on site: it arrives as a single unit ready to connect to water, air ducts and a standard 230V supply.
Using R290 natural refrigerant — the same used in domestic fridge-freezers — the aroSTOR delivers a COP of 3.14 under EN16147 test conditions, producing over three times as much heat energy as it consumes in electricity. It heats water to 60°C using the heat pump alone (no backup required), and up to 65°C when the 1.2kW titanium immersion element is active for boost or anti-Legionella. The 270L model offers 349 litres of usable hot water at 54°C — making it well suited to 4–6 person households or properties with higher demand.
Flexible siting options are a hallmark of the aroSTOR design: a range of 360° air duct accessories (including the optional twin flue kit) allows fresh warm air to be drawn from inside the room, from an adjacent space, or directly from outside through a wall. The unit ships in a purpose-designed transport bag for safe two-person handling without a forklift.
Key Features
All-in-One Integrated DesignHeat pump and 270L cylinder in a single floor-standing column — no outdoor unit, no split system, no refrigerant connections on site. Single footprint; minimum clearance of 300mm on all sides.
R290 Natural Refrigerant · A+ RatedGWP 3, ODP 0, 150g charge. COP 3.14 (EN16147 tapping profile L), seasonal efficiency 130%, ErP A+ rating. Over three times as efficient as direct-electric water heating.
349L Usable Hot Water at 54°CThe 270L cylinder provides 349 litres of usable DHW at 54°C — enough to meet the hot water needs of 4–6 people comfortably without running cold between draws.
~10h 15m Heat-Up at A7 (Full Reheat)Full reheat from cold in heat pump mode takes approximately 10 hours 15 minutes at 7°C ambient (EN16147). For installations running overnight or off-peak, this fits within a single Economy 7 / off-peak window.
1.2kW Titanium Backup ElementCorrosion-resistant, limescale-resistant titanium immersion element for boost or anti-Legionella. Maximum combined power (HP + element) is 1,900W. The unit can also operate on electric-only using "Limp Home" mode.
Up to 60°C Heat Pump OnlyDelivers 60°C without activating the backup element at ambient temperatures within the operating range — a key differentiator of R290 heat pump water heaters, maintaining high COP at maximum DHW temperature.
Stainless Steel Tank · 5-Year WarrantyStainless steel cylinder with polyurethane foam insulation (50mm). OSO corrosion-free construction; no enamel lining or sacrificial anode required. Five-year warranty on the cylinder (two years on other components).
Flexible 360° Air DuctingSupports air drawn from inside the room (ambient), from an adjacent unheated or heated space via internal duct, or directly from outside. Accepts insulated rigid ducts (max 20m) or flexible ducts (max 10m). Min. duct diameter ≥160mm.
Solar PV IntegrationPV-ready: connect a potential-free contact from a solar controller or export relay to switch the unit into PV priority heating mode — using surplus self-generated electricity before exporting to the grid. Two independent PV temperature setpoints configurable (ECO and MAX).
Anti-Legionella · Holiday ModeScheduled anti-Legionella cycle raises the cylinder to maximum temperature to maintain water safety. Holiday mode suspends normal operation (frost protection remains active) for up to 99 days, resetting automatically on return.
Off-Peak / Smart Tariff ReadyProgrammable time schedules allow up to 7 on/off windows per day — set to align with Economy 7, Octopus Go or other cheap-rate tariffs. A dedicated low-tariff terminal accepts an external relay signal from the energy supplier or smart meter.
Extremely Quiet OperationSound power level 52 dB(A). Advanced compressor insulation and rubber vibration isolation mountings suppress operational noise, making the unit suitable for installation in utility rooms adjacent to living spaces.
Recovery & Heat-Up Times
Heat-up and usable volume data are from the official Vaillant aroSTOR brochure, measured under EN16147:2017 test conditions (cold water 10°C inlet, target 55°C, tapping profile L, A7 ambient air temperature).
| Mode & Conditions |
aroSTOR 270L |
| Full reheat from cold — heat pump only (A7, EN16147) |
~10h 15m |
| Boost mode — heat pump + 1.2kW element (1,900W combined) |
Significantly faster — recommended for top-up or urgent demand |
| Maximum usable DHW at 54°C (mixed temperature) |
349 litres |
| COP at A7 (EN16147, tapping profile L) |
3.14 |
| Seasonal energy efficiency |
130% |
| Standby heat loss at 55°C |
1.77 kWh/24h |
| Max air flow rate (non-ducted) |
400 m³/h |
💡 Tip: The aroSTOR's ~10h 15m full reheat time is designed to fit within an overnight off-peak window on Economy 7 or similar smart tariffs. Programme the timer to start heating at the beginning of the cheap-rate period — at current Octopus Go / E7 rates this can cut DHW running costs to as little as 25–30% of an equivalent direct-electric heater. On sunny days, connect to a PV controller to use surplus solar generation for top-up heating.
Technical Specifications
| Specification |
Detail |
| Brand / Range |
Vaillant / aroSTOR |
| Model |
aroSTOR VWL B 270/5 UK |
| Article Number |
0010028218 |
| Tank Capacity |
270L |
| Tank Material |
Stainless steel |
| Insulation |
Polyurethane foam, 50mm |
| Tank Warranty |
5 years (2 years other components) |
| Refrigerant / Charge |
R290 / 0.15kg — GWP 3, ODP 0 |
| Energy Efficiency Class |
A+ |
| Tapping Profile (EN16147) |
L |
| COP (EN16147) |
3.14 |
| Seasonal Efficiency |
130% |
| Max Usable DHW at 54°C |
349 litres |
| Full Reheat Time (heat pump, A7) |
~10h 15m (EN16147) |
| Heat-Up Time Range (initial start-up) |
5–12 hours to reach 55°C (depending on air and cold water temperature) |
| DHW Temperature Range (HP only) |
30–60°C |
| Max DHW Temperature (HP + backup) |
65°C |
| Electric Backup Heater |
1.2kW titanium immersion |
| Max Power (HP only) |
700W |
| Max Power (HP + backup) |
1,900W |
| Ambient Temperature Range (HP) |
-7°C to +35°C |
| Ambient Range (backup heater only) |
Outside -7 to +35°C range |
| Sound Power Level |
52 dB(A) |
| Standby Heat Loss at 55°C |
1.77 kWh/24h |
| Air Flow — Minimum |
320 m³/h |
| Air Flow — Nominal |
350 m³/h |
| Air Flow — Maximum (non-ducted) |
400 m³/h |
| Air Duct — Max Rigid Length |
20m |
| Air Duct — Max Flexible Length |
10m |
| Min Duct Diameter |
≥160mm (insulated) |
| Power Supply |
230V / 1ph / 50Hz |
| Max Circuit Amperage |
8A |
| Fuse Size |
13A |
| IP Rating |
IPX4 |
| Electrical Cable (supplied) |
1.5m |
| Max Pressure |
6 bar |
| T&P Relief Valve Pressure / Temp |
7 bar / 90°C |
| Water Connections |
M 3/4" (hot, cold, T&P) |
| Dimensions (Ø × H) |
634mm × 1,783mm |
| Min Clearance (all sides) |
300mm |
| Min Room Height |
≥2,200mm |
| Weight (empty) |
68 kg |
| Weight (filled) |
338 kg |
What's Included
In the Box
aroSTOR unit with integrated controller, polyurethane foam insulation, transport bag.
Accessories: Safety group (expansion relief valve and connections for DHW circuit), condensate discharge siphon, installation and operating manuals.
Air ducting, additional G3 safety fittings (if required by local building control), and optional twin flue kit are not included — see Vaillant aroSTOR VWL 290 Twin Flue Kit available separately.
Frequently Asked Questions
How long does the aroSTOR 270L take to heat up from cold?Under EN16147 test conditions (7°C ambient air, 10°C cold water inlet), the 270L model takes approximately 10 hours 15 minutes to reach 55°C in heat pump mode. At initial start-up, Vaillant states the time can be between 5 and 12 hours depending on actual air temperature and cold water temperature. The unit is designed for continuous operation with programmed heating schedules — it should remain switched on at all times for normal use.
How much usable hot water does the 270L aroSTOR provide?The 270L aroSTOR provides 349 litres of usable hot water at 54°C (mixed temperature), per EN16147 test data. This makes it well suited to 4–6 person households or properties with higher hot water demand — significantly more usable output than the nominal tank volume because hot water is stored at up to 60°C and mixed with cold at the draw-off point.
Does the aroSTOR need a separate outdoor unit?No. The aroSTOR is a fully integrated unit — the heat pump evaporator, fan, compressor and controller are all built into the upper section of the same floor-standing column as the cylinder. There is no outdoor unit, no split-system refrigerant pipework, and no need for F-Gas certified engineers for installation. Only standard plumbing, ducting and electrical connections are required on site.
Can the aroSTOR work with solar PV?Yes. The unit has a dedicated PV input terminal on the PCB that accepts a potential-free contact from a solar controller, export relay or smart energy manager. When activated, it switches to PV heating mode — using surplus self-generated electricity to heat the tank to a higher setpoint temperature. Two independent PV temperature levels can be configured: a lower T°PV ECO (heat pump only) and a higher T°PV MAX (heat pump + backup element).
What ducting does the aroSTOR require?The unit draws in warm air and exhausts cooler air through 160mm (minimum) insulated round ducts. Maximum rigid duct length is 20m, maximum flexible duct length is 10m. Air can be drawn from inside the room (ambient), from an adjacent space via internal ducting, or directly from outside. The optional Vaillant aroSTOR VWL 290 Twin Flue Kit allows both intake and exhaust to be routed through a single wall penetration. Do not connect the unit to kitchen extractor hoods.
🔧 Installation Notes
The Vaillant aroSTOR VWL B 270/5 UK is a mains-pressure unvented heat pump water heater and must be installed in accordance with Building Regulations Part G3, the manufacturer's installation manual (ref. 0020285063), and all applicable UK water and electrical regulations. Key installation requirements are summarised below.
⚡ Electrical Supply230V / 1ph / 50Hz; maximum circuit amperage 8A; 13A fuse. The unit is supplied with a 1.5m electrical cable. A separate low-tariff terminal accepts an external relay for off-peak tariff control.
🌡️ G3 Unvented ComplianceMust be installed and commissioned by a G3-qualified engineer and notified to building control under Part G3. Safety group, expansion vessel and T&P valve must be correctly sized and installed.
💨 Air DuctingMin. duct diameter ≥160mm, insulated to prevent condensation. Max. rigid duct 20m, max. flexible duct 10m. Do not connect to extractor hoods. Minimum room height ≥2,200mm. The optional twin flue kit (part 20205775) allows single-wall through-wall installation.
🚰 T&P Valve DischargeThe 7 bar / 90°C T&P valve must discharge to a safe visible location via a correctly sized discharge pipe per Water Regulations and the installation manual.
💧 Condensate DrainThe unit produces condensate during heat pump operation. The condensate siphon must be filled with water before commissioning and connected to a suitable drain with a continuous fall and no kinks.
🔩 Floor Loading & ClearancesInstall on a flat, level surface capable of supporting 338 kg (filled weight). Minimum 300mm clearance on all sides. Minimum room height 2,200mm. The unit is top-heavy — two people required for safe handling using the supplied transport bag.
For full installation instructions, please refer to the manufacturer's installation manual (ref. 0020285063) supplied with the unit.
