The Panasonic Aquarea WH-ADC0509L3E5UK is the All-in-One indoor unit for the R290 L Generation hydro split range — a single compact cabinet combining the hydromodule and a 185 litre DHW cylinder in one unit, with a footprint of just 599 × 602 mm, similar to a standard domestic appliance. It's a hydraulic connection only — refrigerant stays entirely within the outdoor unit — and pairs with any of the three L Generation outdoor units (5 kW, 7 kW or 9 kW), so you choose your heating capacity independently of the indoor unit itself.
185 L
Built-in DHW cylinder
A+++ / A+
Heating / DHW rating
-25°C
Operation without backup heater
One indoor unit, three outdoor capacities
The WH-ADC0509L3E5UK indoor unit is common across the 5 kW, 7 kW and 9 kW L Generation outdoor units (WH-WDG05LE5 / WH-WDG07LE5 / WH-WDG09LE5) — size your outdoor unit to your calculated heat loss, and this same indoor unit completes the system regardless of which capacity you choose.
Hydraulic connection — indoor unit powers the outdoor unit
This is a hydro split design: only water pipework runs between indoor and outdoor units, up to a maximum separation of 30 metres. The outdoor unit draws its power and communication through the indoor unit, so no separate power supply run to the outdoor unit is required.
MCS-certified installer required
To claim the UK Boiler Upgrade Scheme grant and validate full Panasonic manufacturer warranty, this system must be installed and commissioned by an MCS-certified heat pump installer.
Compatible outdoor units
Choose your outdoor unit capacity
| Heating output |
Outdoor unit model |
Typical property fit |
| 5 kW |
WH-WDG05LE5 |
Small, well-insulated 1–2 bedroom homes and flats |
| 7 kW |
WH-WDG07LE5 |
Typical 2–3 bedroom UK homes |
| 9 kW |
WH-WDG09LE5 |
3–4 bedroom homes and larger properties needing high flow temperatures |
Sizing tip
Choose your outdoor capacity from a calculated room-by-room heat loss survey — the WH-ADC0509L3E5UK indoor unit and its 185 L cylinder stay the same across all three capacities, so sizing decisions rest entirely on the outdoor unit.
Key features
185 litre built-in DHW cylinder
Stainless steel tank with a U-Vacua vacuum insulation panel integrated into the same cabinet as the hydromodule — no separate cylinder or airing cupboard needed.
Appliance-sized footprint
At 599 × 602 mm, the cabinet footprint is comparable to a standard domestic appliance — genuinely space-saving compared with a separate hydrobox-plus-cylinder arrangement.
R290 refrigerant — GWP 0.02
Natural propane refrigerant with a Global Warming Potential of just 0.02 — dramatically lower than legacy refrigerants, and the most future-proof choice ahead of tightening F-Gas regulation.
Flow temperatures up to 75°C
Delivers 75°C water outlet temperature at -10°C outside temperature — ideal for retrofit properties keeping existing radiators, avoiding the cost of re-sizing emitters.
DHW to 65°C without a backup heater
Reaches 65°C domestic hot water from the heat pump alone, reducing reliance on the electric backup element for day-to-day hot water production.
Operates to -25°C without backup heating
Sustains full heat pump operation down to -25°C ambient without needing to call on backup heat — genuinely engineered for cold UK winters.
Built-in magnetic water filter
Integrated magnetic filter protects the primary circuit from debris without needing a separate in-line filter fitted on site.
A+++ heating / A+ DHW efficiency
Rated A+++ in heating at 35°C and A+ in DHW — strong seasonal efficiency across both heating and hot water duties.
Technical specification
| Model code (indoor unit) |
WH-ADC0509L3E5UK |
| Type |
Hydro split All-in-One indoor unit with integrated DHW cylinder |
| Compatible outdoor units |
WH-WDG05LE5 (5 kW) / WH-WDG07LE5 (7 kW) / WH-WDG09LE5 (9 kW) |
| Built-in DHW cylinder capacity |
185 litres |
| Cylinder construction |
Stainless steel with U-Vacua vacuum insulation panel |
| Refrigerant |
R290 (GWP 0.02) — outdoor unit only, hydraulic connection to indoor |
| Maximum water outlet temperature |
75°C at -10°C outside temperature |
| DHW temperature without backup heater |
Up to 65°C |
| Operating range without backup heating |
Down to -25°C ambient |
| Heating efficiency rating |
A+++ (at 35°C) |
| DHW efficiency rating |
A+ |
| Indoor unit dimensions (W × D × H) |
599 × 602 × 1642 mm |
| Indoor unit weight |
93 kg |
| Maximum indoor/outdoor separation |
30 metres |
| Backup immersion heater |
3 kW |
| Built-in expansion vessel (heating) |
10 litres (additional vessel may be required to meet system requirements) |
| Safety valve pressure rating |
8 bar |
| Built-in water filtration |
Magnetic water filter (integrated) |
| Power supply — main unit |
230V, single-phase, 25A isolator |
| Power supply — backup heater |
230V, single-phase, 15/16A isolator |
| Outdoor unit power/communication |
Supplied via the indoor unit — no separate outdoor power run required |
| Connectivity |
Aquarea Smart Cloud Wi-Fi compatible (adaptor required) |
| Zone control |
Single-zone as standard; two-zone with optional PCB |
| Certifications |
MCS certified, BUS grant eligible |
What's in the box
- Panasonic WH-ADC0509L3E5UK All-in-One indoor unit (hydromodule + 185L cylinder)
- Built-in 3 kW backup immersion heater
- Built-in magnetic water filter
- Manufacturer installation and operating instructions
What you'll also need (sold separately)
- Matched L Generation outdoor unit — WH-WDG05LE5 / WH-WDG07LE5 / WH-WDG09LE5 (see variant selector above)
- Aquarea Smart Cloud Wi-Fi adaptor for smartphone app access
- Optional PCB (for two-zone control, solar connection, or bivalent boiler backup)
- Additional expansion vessel if system volume exceeds the built-in 10L capacity
- Discharge pipework to a suitable tundish and drain point
- Buffer tank thermistor, if a separate buffer tank is included in your system design
Frequently Asked Questions
Which outdoor unit should I choose?
Choose the capacity that matches your calculated heat loss. As a rough guide: 5 kW for small well-insulated 1–2 bed homes; 7 kW for typical 2–3 bed homes; 9 kW for 3–4 bed homes and larger properties needing high flow temperatures. The indoor unit and its 185 L cylinder are identical across all three capacities.
Is 185 litres enough hot water for my household?
185 litres suits typical 2–3 bedroom households with moderate to good hot water demand. Panasonic specifically position the All-in-One as ideal for lower DHW demand properties given its compact, appliance-sized footprint — larger households with higher demand may prefer a separate hydrobox plus a larger stand-alone cylinder instead.
Does refrigerant run through the indoor unit?
No — this is a hydro split design. Only water pipework connects the indoor and outdoor units, up to 30 metres apart. The R290 refrigerant circuit is fully contained within the outdoor unit.
Do I need to run a separate power supply to the outdoor unit?
No — the outdoor unit's power and communication come via the indoor unit, so a direct power supply run to the outdoor unit isn't required. Refer to the installation manual for the correct isolator ratings on the indoor unit's two power supplies (main unit and backup heater).
Can this support two heating zones?
The system is single-zone as standard. Two-zone control — along with solar connection, bivalent boiler backup and other advanced functions — is available by fitting the optional PCB.
Do I need to be MCS-registered to install this?
The system can be installed by any competent heating engineer, but to claim the UK Boiler Upgrade Scheme grant the install must be carried out by an MCS-certified installer. Quality Heating can put you in touch with our trade partners if needed.
