What Is the Panasonic Aquarea WH-MXC09J3E5?
The Panasonic Aquarea WH-MXC09J3E5 is a 9 kW air-to-water heat pump from the Aquarea High Performance J-Series. The system uses a monobloc design with a factory-sealed R32 refrigerant circuit, paired directly with an indoor WH-SXC09J3E5 hydro unit. Superior low-temperature efficiency delivers an ErP A+++ rating at 35 °C flow alongside a 4.50 SCOP. This page provides an independent technical overview of the system’s real-world operational parameters rather than a sales pitch. Reliable heating capacity sustains 9.0 kW with a 4.84 COP at A7/W35, maintaining 7.0 kW at −7 °C outdoor conditions with a 2.85 COP. **Broad system flexibility** supports leaving water temperatures up to 60 °C down to −20 °C ambient. To evaluate other capacities, review the full Panasonic Aquarea heat pump range.
Key Specifications at a Glance
The manufacturer specifications define the core electrical, mechanical, and thermal parameters for the 9 kW monobloc unit. Properties with lower design heat loss calculations should evaluate the 7 kW WH-MXC07J3E5 to prevent short-cycling.
| Parameter | Value |
|---|---|
| Heating output A7/W35 | 9.0 kW |
| COP A7/W35 | 4.84 |
| SCOP 35 °C | 4.50 |
| ErP class | A+++ |
| Refrigerant | R32 |
| Min outdoor temp | −20 °C |
| Max water temp | 60 °C |
| Sound pressure 1 m | ~49 dB(A) |
| Outdoor dimensions | 1,340 × 940 × 340 mm |
| Indoor dimensions | 892 × 500 × 340 mm |
| Power supply | 230 V / 1-phase / 50 Hz |
| MCB rating | 25 A Type C |
Performance in Real UK Conditions
Laboratory test ratings at mild ambient temperatures fail to reflect operational reality during peak UK heating demand, where near-freezing conditions and high ambient humidity degrade heat exchanger efficiency, trigger defrost cycles, and suppress seasonal performance across domestic installations.
Tested in accordance with the EN 14511 standard, verified thermal capacity and efficiency ratings scale across ambient ranges:
- A7/W35: 9.0 kW output | 4.84 COP
- A2/W35: 8.2 kW output | 3.80 COP
- A−7/W35: 7.0 kW output | 2.85 COP
With Met Office climate data recording average January lows around 2 °C across SE England and −1 °C in Scotland, core heating season hours cluster between 0 °C and 7 °C. Consequently, the A2/W35 rating of 3.80 COP serves as the practical operational benchmark, illustrating how heat pump COP changes in UK winters.
In hard-water supply regions exceeding 200 mg/L CaCO₃, thermal cycling accelerates scaling across the internal plate heat exchanger, restricting flow and impairing heat transfer. System designers across SE England, East Anglia, and the East Midlands should incorporate an inline side-stream filter to maintain hydraulic efficiency and protect compressor longevity.
Installation and Electrical Requirements
The WH-MXC09J3E5 requires a dedicated 230 V single-phase circuit, precise hydraulic planning, and adequate airflow clearances to maintain rated seasonal efficiency and comply with UK domestic electrical safety regulations.
- Overcurrent Protection: Recommended 25 A Type C MCB sized for the unit’s ~18 A maximum running current.
- Supply Cabling: 3-core 4 mm² SWA copper cable, selected and verified against BS 7671 run-length regulations.
- Hydraulic Connections: 1″ BSP male flow and return connections, requiring vapor-sealed exterior thermal insulation.
- Minimum System Volume: 40 L active primary circuit volume; install a dedicated buffer vessel if system volume is insufficient.
- Condensate Drainage: Unobstructed gravity discharge or trace-heated routing to prevent winter ice accumulation around the base.
- Siting Clearances: Minimum 300 mm rear and side clearance, with 600 mm unobstructed frontal clearance for fan discharge.
- Accreditation: Must be installed and commissioned by an MCS-certified contractor to qualify for the £7,500 Boiler Upgrade Scheme grant.
The factory-sealed monobloc architecture contains all R32 refrigerant within the outdoor casing, eliminating indoor refrigerant pipework and simplifying site-level F-Gas regulatory compliance.
Controls, Smart Connectivity, and BMS Integration
The WH-MXC09J3E5 includes the CZ-RTC5 wired room thermostat as standard, handling core system commissioning, fault diagnostics, and weather compensation curves. Adding the optional CZ-TAW1 communication module expands smart heat pump control options by enabling cloud-based management through Wi-Fi or Ethernet via the Panasonic Comfort Cloud app.
- Remote Scheduling: Configure detailed weekly heating schedules, holiday modes, and domestic hot water set-points from any connected device.
- Energy Monitoring: Track real-time and historical electrical consumption alongside calculated coefficient of performance metrics.
- SG-Ready Response: Trigger automatic flow-temperature boosts or thermal storage cycles using photovoltaic array generation or smart-grid signals.
- BMS Integration: Connect with third-party home automation using onboard 0–10 V, OpenTherm, and dry volt-free contacts.
The SG-Ready capability allows automated preheating during cheap pricing windows on agile tariffs from suppliers like Octopus and E.ON Next, cutting operational running costs without sacrificing comfort.
Heat Pump Sizing. Is 9 kW Right for Your Property?
The 9 kW output suits properties with a design heat loss between 6.5 and 9.5 kW, delivering sufficient thermal capacity at peak outdoor design temperatures while modulating down effectively to prevent inefficient short-cycling during milder transitional weather.
Typical matching buildings include well-insulated post-2005 three-bedroom semi-detached properties (fabric U-values ≤ 0.3 W/m²K) or older pre-1990 three-to-four-bedroom homes that have undergone extensive thermal retrofits, such as 300 mm loft insulation, filled cavity walls, and low-temperature radiator or underfloor heating emitter upgrades operating at 35–45 °C flow.
- Always commission a BS EN 12831 room-by-room heat-loss calculation before selecting output.
System over-sizing causes excessive cycling at minimum inverter modulation, degrading real-world seasonal efficiency and stressing mechanical components. Conversely, installing this 9 kW unit in a property with a heat loss exceeding 12 kW causes continuous running deficits and triggers expensive internal backup immersion heaters during sub-zero winter cold snaps.
If calculated heat loss falls outside this operating envelope, assess the 7 kW variant for lower-demand structures or the 12 kW WH-MXC12J3E5 for larger, uninsulated properties.
Pricing & Running-Cost Context
Upfront capital expenditure for the Panasonic Aquarea WH-MXC09J3E5 is substantially mitigated across England and Wales through central government decarbonisation incentives, narrowing the net capital outlay gap against fossil boiler replacements.
- Supply-Only Unit Cost: £3,200–£3,900 inc. VAT for the outdoor monobloc and indoor hydro paired set.
- Typical Installed Cost: £10,500–£13,500 via an MCS-certified installer, including cylinder, system filters, controls, and commissioning.
- Boiler Upgrade Scheme (BUS) Grant: £7,500 non-repayable voucher applied directly to installation invoices.
- Net Effective Cost: £3,000–£6,000 consumer outlay following statutory grant deduction.
When evaluating heat pump running costs vs gas boilers under the July 2024 Ofgem price cap, mains gas costs 6.04 p/kWh. By comparison, standard electricity at 24.5 p/kWh delivering a 4.50 SCOP produces an effective heat cost of 5.4 p/kWh, maintaining thermal parity before integrating smart dynamic tariffs.
FAQ
What size property does the Panasonic WH-MXC09J3E5 suit?
It suits properties with a design heat loss between 6.5 and 9.5 kW, typically modern well-insulated three-bedroom homes or retrofitted three-to-four-bedroom properties equipped with low-temperature radiators or underfloor heating.
Does the WH-MXC09J3E5 need a separate hot-water cylinder?
Yes. As a space-heating monobloc paired with an indoor hydro unit, it requires an external unvented cylinder fitted with a high-surface-area heat pump coil to supply domestic hot water.
What refrigerant does the Aquarea WH-MXC09J3E5 use?
The unit uses R32 refrigerant with a GWP of 675. The 1.55 kg charge is factory-sealed inside the outdoor casing, removing the requirement for on-site refrigerant pipework or F-Gas handling.
Can I install the WH-MXC09J3E5 myself?
While physical plumbing is manageable without F-Gas handling, electrical connections must meet BS 7671 standards, and claiming the £7,500 BUS grant requires commissioning by an MCS-certified installer.
What is the noise level of the outdoor unit?
The outdoor unit operates at a sound power level of 64 dB(A), resulting in an acoustic sound pressure level of approximately 49 dB(A) at a one-metre distance.
