The Panasonic Aquarea L Series R290 is Panasonic's original propane hydro-split heat pump, purpose-built for UK retrofit where existing radiators need to stay in place. Its defining feature is the hydro-split architecture: the R290 refrigerant circuit and compressor stay entirely within the outdoor unit, and only water is pumped indoors — the same principle used in a monobloc, but engineered specifically to unlock 75°C flow temperatures without moving refrigerant into the building. Available in three capacities from 5 kW to 9 kW.
SCOP up to 5.06
Peak efficiency
BUS grant eligible
Panasonic Aquarea R290 heat pumps are eligible for the UK Boiler Upgrade Scheme grant when installed by an MCS-certified installer in an eligible property.
R290 outdoor unit siting
R290 is an A3 flammable refrigerant. UK installation requires minimum clearances from openings, drains and ignition sources per Panasonic's technical manual. Most domestic gardens accommodate the unit easily.
MCS-certified installer required
To claim the BUS grant and validate full Panasonic manufacturer warranty, this heat pump must be installed and commissioned by an MCS-certified heat pump installer.
Choose your capacity
| Heating output |
Typical property fit |
| 5 kW |
Small, well-insulated 1–2 bedroom homes and flats |
| 7 kW |
Typical 2–3 bedroom UK homes |
| 9 kW |
3–4 bedroom homes and larger properties needing high flow temperatures |
Sizing tip
Choose your capacity from a calculated room-by-room heat loss survey, not from bedroom count alone. The L Series is specifically aimed at retrofit properties keeping existing radiators — confirm your radiators can deliver the required output at the heat pump's flow temperature before committing to a capacity.
Why choose the L Series
R290 refrigerant — GWP 3
Propane refrigerant with a GWP of just 3 — close to one-thousand times lower than legacy split heat pump refrigerants. The most future-proof choice ahead of tightening UK F-Gas regulation.
Flow temperatures up to 75°C
Delivers 75°C flow at -10°C ambient — genuinely engineered for retrofit properties keeping existing radiators, where lower-flow-temperature heat pumps would need emitter upgrades.
Hydro-split — refrigerant stays outside
Only water moves between outdoor and indoor units — no refrigerant pipework crosses into the building, simplifying installation and avoiding in-property F-Gas handling.
Reduced sound level
Panasonic quote up to 8 dB(A) quieter than previous-generation models — comfortable for boundary-sensitive sites.
Strong seasonal efficiency
SCOP up to 5.06 across the range — genuinely competitive efficiency alongside the high flow temperature capability.
Aquarea Smart Cloud
Built-in Wi-Fi connectivity to the free Aquarea Smart Cloud app — schedules, energy monitoring and fault alerts from a smartphone.
Platform specification (all variants)
| Range |
Panasonic Aquarea L Series |
| Architecture |
Hydro split — refrigerant circuit contained in outdoor unit, water circulated to indoor unit |
| Available capacities |
5 kW / 7 kW / 9 kW |
| Refrigerant |
R290 propane (GWP 3, sealed factory charge) |
| SCOP |
Up to 5.06 depending on capacity and conditions |
| Maximum flow temperature |
75°C at -10°C ambient |
| Sound level |
Up to 8 dB(A) quieter than previous generation Panasonic models |
| Electrical supply |
230V, 50Hz, 1-phase |
| Connectivity |
Aquarea Smart Cloud Wi-Fi (built in) |
| Best-suited application |
Retrofit properties with existing radiators, where high flow temperature avoids emitter replacement |
| Certifications |
MCS certified, BUS grant eligible |
What's in the box (every variant)
- Panasonic Aquarea L Series R290 outdoor unit (capacity per selected variant)
- Manufacturer installation and commissioning documentation
- Panasonic UK warranty registration documentation
What you'll also need (sold separately)
- Panasonic Aquarea L Series indoor bi-bloc unit (see our L Series indoor unit listings)
- DHW cylinder (heat-pump-suitable, indirect coil sized for low flow temperature)
- Outdoor wall bracket or floor stand
- Anti-freeze valves on primary flow and return
- Magnetic system filter on the primary return
Frequently Asked Questions
Which kW should I choose?
Choose the variant 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. Always confirm with a heat loss survey before ordering.
What's the difference between L Series and M Series R290?
L Series is Panasonic's original R290 hydro-split range, capped at 9 kW, purpose-built for domestic retrofit with high flow temperatures. M Series is the newer, modular platform running 9–16 kW residential (up to 30 kW commercial), with T-CAP cold-climate technology and a choice of four indoor-unit configurations. If your property needs more than 9 kW, or you want the flexibility of a standalone controller-only setup, M Series is the one to look at.
Will my existing radiators work with the L Series?
In most retrofit cases, yes — the L Series's 75°C flow temperature is specifically engineered so existing radiators sized for a gas boiler will usually deliver enough output without uprating. A heat loss survey identifies any coldest-rooms exceptions.
Is R290 safe for a domestic installation?
Yes. R290 is widely used across Europe in domestic heat pumps and refrigeration. In the L Series, the refrigerant is sealed inside the outdoor unit — the hydro-split design means only water crosses into the property. UK installation rules govern minimum outdoor siting clearances; a competent designer will ensure these are met.
Do I need to be MCS-registered to install this?
The unit can be installed by any competent heating engineer, but to claim the Boiler Upgrade Scheme grant the install must be by an MCS-certified installer. Quality Heating can connect you with our trade network.
Does the L Series include the indoor unit?
No — this listing is the outdoor unit only. Pair it with a Panasonic Aquarea L Series bi-bloc indoor unit at the matching capacity — see our L Series indoor unit listings.
