Rinnai HydraHeat® Split Hot Water Heat Pump

Introducing the HydraHeat® Split – a versatile solution compatible with both new and existing cylinders*.

Key Features

• Up to 75% Energy Savings*: Provides highly efficient water heating, minimising energy consumption and lowering operating costs.
• High Coefficient of Performance (COP) of 4.6 – providing energy efficiency**: Maximises energy output while minimising input for reliable, cost-effective hot water heating — ideal for energy-conscious households.
• Faster Top-Down Heating: Delivers hot water directly to the top of the cylinder from startup, ensuring hot water is available right when you need it.
• Dedicated to Sustainability: Uses only 150g nominal charge of R290 natural refrigerant.
• Frost Protection: Built-in defrost and frost protection functions allow operation in colder climates.
• 4 Operation Modes: Eco 55, Standard, Element Only, and Shutdown.
• Quiet Operation: Operates quietly for enhanced noise comfort for users and nearby neighbours.
• Ease of Installation: Outdoor compressor unit heats water efficiently using ambient air — perfect for homes with limited indoor space.
• Split Design – Easy Retrofit*: Can be connected to your existing hot water cylinder without requiring a full replacement.
• Warranty – 5 Years: 5-year heat pump module warranty for peace of mind.
• Modern Design: Cod Grey colourway offers sleek, modern aesthetics.

* When compared to a 250L standard electric hot water cylinder heating water from 19°C to 55°C. ** COP measured at: Inlet water temp. 19°C, Outlet water temp. 55°C, Dry Bulb temp. 19°C. *** Refer to the cylinder compatibility checklist to confirm compatibility with the HydraHeat® Split system.

Technical Specifications

Model Number / Order Code

• RHPN361S

Cylinder Compatibility CriteriaThe cylinder connected to the HydraHeat® Split must meet all the following criteria (onsite inspection recommended if unsure):

• Single element¹ mains pressure cylinder, 180–340 L, element size 3 kW or less
• Rinnai, HJ Cooper, or Rheem cylinder that is 8 years old or less
• Not connected to supplementary heating (e.g., wetback, solar thermal)
• Cylinder with TPR rated 10 kW or more
• Pipe run length < 20 m (15 m cable supplied; 5 m extension available)
• Height difference between cylinder base and heat pump base ≤ 5 m
• Adequate clearance to install cylinder connections (for indoor cylinders)
• Minimum water pressure: 100 kPa
• ECV of 700 kPa or less must be fitted
• Cylinder thermostat set to 70 °C (required for 'Element only' mode and Legionella disinfection)

¹ Cylinder element must be operational and properly connected for compliance and Legionella protection.

Performance Specs

• Coefficient of Performance (COP): 4.6 (Inlet water temp: 19 °C, outlet: 55 °C, ambient: 19 °C)
• Outlet Water Temperature: Standard: 60 °C Eco: 55 °C
• Storage Capacity: Based on connected cylinder
• Hot Water Recovery Rate: 86 L/h (Eco 55 mode, 19 °C ambient, 36 °C rise)

Valve & Pressure Requirements

• TPR: Refer to manufacturer’s spec
• Cold Water Expansion Valve: 700 kPa (must be installed)
• Pressure Limiting Valve: 500 kPa
• Minimum Inlet Water Pressure: 100 kPa

Electrical & Power Info

• Rated Heat Pump Input/Output: 765 W / 3600 W
• Max Current (Standard Mode): 4.6 A
• Max Current (Element Only): 14.5 A
• Backup Resistance Element: 3000 W
• Power Supply: 230–240 V / 50 Hz

Physical Specs

• Dimensions (H x W x D): 750 mm x 835 mm x 365 mm
• Weight: Net 42.5 kg / Gross 50 kg
• IP Rating: IP24
• Water Port Connections: G½” (15 mm x 2)
• Sound Pressure Level (1 m): 48 dB(A) (Measured in standard mode @ 19 °C ambient)
• Data Label Position: Behind front cover (between compressor and fan)

Refrigerant

• Type: R-290
• Charge: 150 g

Accessories

• R1886: Touch-up paint, Cod Grey, 400 ml aerosol can
• R1012: HydraHeat® Split 5 m extension cable (Standard 15 m cable supplied; extension required if distance exceeds 15 m)

Market Release

• April 2025