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The experts in water heaters and heat pumps have combined the technology of both to bring you a very clever solution – a Hot Water Heat Pump called HydraHeat®. Using the efficiency of heat pump technology, HydraHeat® will heat a home’s water while saving you up to 75% on your water heating costs*. The result is a far more cost-effective and more sustainable solution for the homes of tomorrow.
This energy-efficient hot water heat pump is eligible for an NZ Green Energy Loan.
The HydraHeat® head unit has been designed and built right here in New Zealand for Kiwi conditions, and the whole system is easy to install for any home.
- Description
- Specifications
- Downloads
Description
Product Details

Provides highly efficient water heating, minimising energy consumption and lowering operating costs.

Powered by only 150g (nominal charge) of high-efficiency R290 refrigerant with low Global Warming Potential and COP of 4.7.

Crafted with exceptional quality by Rinnai New Zealand, the trusted name in total home living.

Specifically designed for New Zealand climatic conditions (from -10°C to +42°C), as well as coastal locations. Operates in full heat pump mode right down to -10°C without the need for electric boosting.

The inbuilt electric element guarantees a consistent and dependable supply of hot water, at all times.

Upgrade from a standalone HydraHeat® electric cylinder to Hot Water Heat Pump Technology by adding the HydraHeat® head unit.

Removable Heat Pump unit allows for easy servicing, and ensures uninterrupted supply of hot water.

Built-in defrost and frost protection functions to handle colder climates.

MEPS (Minimum Energy Performance Standard) means less heat loss from unit and less energy use, resulting in a more efficient product. Not all Hot Water Heat Pumps in New Zealand are MEPS compliant.

5-year heat pump unit warranty and a 7-year cylinder warranty.

Features OLED screen and six operation modes for versatility.

Standard, Boost, Eco 55, Eco 50, High Usage, and Element Only.

The 275L is suitable for homes of 2-5 people and the 340L is suitable for 2-7 people. Plus an operating sound level of only 45dB(A) makes it suitable for a wide range of homes, including built-up residential areas.
* When a comparison calculation is made to a 250L standard electric hot water cylinder when heating water from 19°C to 55 °C.
** Coefficient of Performance was measured at the following conditions: Inlet water temperature 19°C, Outlet Water temperature 55°C, Dry Bulb Temperature 19°C.
Product Description
The Rinnai HydraHeat® is designed primarily for outdoor installations. It may be possible to install internally if the proposed location is not an occupied space as defined by AS/NZS 5149, consult a qualified installer prior to installation.
Scope of Use
Primarily designed for residential applications.
Not suitable as a spa or swimming pool heater. Not suitable for hydronic or for in-series installation in ring main systems*.
Hard and acidic water will need to be treated to use this product, refer water quality parameters in the support material (downloads).
Technical Specifications
| Model number / order code | 275L – RHPN361A275E20 340L – RHPN361A340E20 |
| Storage capacity | 275 L & 340 L |
| COP | 4.7 W/W (inlet water temp 19 ºC, outlet water temp. 55 ºC, ambient temp. 19 ºC) Accredited Testing to AS/NZS 5125 by NATA accredited Provider.
|
| Rated heat pump input / output | 802 W / 3725 W
In standard, eco 50/55 modes, the heat pump provides 100% of the heating within the operating range. Outside these limits the electric element will operate. |
| Hot water recovery rate | 89 L/h
Recovery rate is calculated at Eco 55 mode, 19 ºC ambient temp., 36 ºC rise.
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| Cylinder element rating | 2 kW |
| Cylinder construction | Enamel |
| Colour | Dune
Bunnings colour match for cylinder (for touchups):
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| Head unit data label position | Positioned on the divider panel between the fan and compressor—to the right of the control panel. |
| Operating temperature | -10 to 42 ºC |
| Noise level | 45 dB(A)
Sound pressure level measured at 1 m distance from the water heater in a free field. Appliance operated in standard mode (60 ºC) at an ambient temperature of 19 ºC.
|
| Refrigerant type | R290 / 150 g (nominal charge) |
| Modes of operation |
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| Dimensions |
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| Water supply and connections |
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| Weights |
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| IP rating | IPX4 header and cylinder |
| Market release | 275L: Nov 2023 340L: Oct 2024 |
| MasterSpec link | ![]() |
Hot Water Heat Pump Comparison
HydraHeat Integrated operation guide
HydraHeat Integrated installation guide
HydraHeat Integrated SDoC 275L
HydraHeat Integrated SDoC 340L
CAD/BIM Downloads
Model: HydraHeat Head and 275L Cylinder
BIM (RevitRFA)
Model: HydraHeat Head and 340L Cylinder
BIM (RevitRFA)
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