Water Heating 19 February 2024

Announcing Rinnai HydraHeat™ - a new generation of Hot Water Heat Pumps.

We are thrilled to announce the release of the Rinnai HydraHeat™ Hot Water Heat Pump.

Rinnai have combined the technology of water heaters and heat pumps to bring you a very clever solution - a Hot Water Heat Pump called HydraHeat™.

Designed and built right here in New Zealand by Rinnai for Kiwi conditions, HydraHeat™ is easy to install in any home. It features a modular ‘Heat Pump Ready’ design and is powered by only 150g of high-efficiency R290 refrigerant with low Global Warming Potential.

Introducing Rinnai HydraHeat™: The Future of Heating Technology

Energy efficiency is a hot topic in the world of heat technology, and for many homeowners, it’s a key factor in the purchase decision process; not only do energy-efficient appliances have a lighter environmental footprint, they’re also kind to the wallet. 

Looking long-term at how New Zealand might deal with issues around energy availability and environmental change, coupled with the knowledge that homeowners are looking for hot water solutions that will have a minimal impact on their energy bills and the environment, Rinnai set out to develop a water heating system that ticked all the boxes.

Rinnai HydraHeat™: Bringing Innovation and Sustainability to Your Home

One of the standout features of the Rinnai HydraHeat™ Hot Water Heat Pump is its commitment to sustainability.

Using the efficiency of heat pump technology, HydraHeat™ will heat a home’s water while saving homeowners up to 75% on hot water heating costs*. The result is a far more cost-effective and sustainable solution for New Zealand homes.

Most conventional water heating systems have a 1:1 energy to heat ratio, meaning when you put one unit of energy into the appliance, you will have one unit of energy delivered to heat the water. 

The HydraHeat™ Hot Water Heat Pump works to a ratio of one unit of energy into the appliance and can generate up to 4.7 units of energy delivered to heat the water - resulting in the use of less energy to heat the same amount of water as a conventional water heater. This not only translates to reduced utility costs but also contributes to a greener planet by lowering the overall carbon footprint of your home.

Learn more about how a HydraHeat™ Hot Water Heat Pump Works

Why Choose a HydraHeat™ Hot Water Heat Pump for your home?

Eco-friendly water heating system

With a focus on developing a Hot Water Heat Pump System that sets new standards for efficiency, sustainability and comfort, Rinnai has considered the environmental impact of the components of their system, opting for a refrigerant with a very low Global Warming Potential (GWP).

This refers to how much thermal radiation the gas would absorb and thus contribute to global warming. The lower the GWP of a refrigerant, the less impact it has. The HydraHeat™ Hot Water Heat Pump uses R290 refrigerant which has a GWP of 3.3. Other commonly used refrigerants like R32 has a GWP of 632, and R410a has a GWP of 1900.

The Rinnai HydraHeat™ has also just received the prestigious Rinnai Environmental Award. This accolade was fiercely contested on a global scale, with submissions from all Rinnai subsidiaries. The Rinnai HydraHeat™ claimed the top spot, surpassing 256 other entries. We take great pride in the exceptional achievements of our New Zealand-based R&D team.

Benefits of a HydraHeat™ Hot Water Heat Pump


1. Energy Efficiency

Rinnai HydraHeat™ Hot Water Heat Pumps are significantly more energy-efficient than traditional electric or gas water heaters. They use renewable heat sources like air, which require less electricity to heat water. This leads to reduced energy consumption and lower power bills.

2. Save Money

Hot water makes up 30-40% of a domestic hot water bill – about $125 per person per year. A Rinnai HydraHeat™ Hot Water Heat Pump should save an average home 60-75% of their hot water cost, depending on time of year and location.

3. Environmental Impact

A Rinnai HydraHeat™ Hot Water Heat Pump uses heat in the air, reducing greenhouse gas emissions and dependence on fossil fuels. This makes them a viable choice for environmentally conscious homeowners and organisations striving to minimise their carbon footprint.

4. Sustainable

Hot water heat pumps are regarded as the most environmentally friendly hot water solution in the market.

5. Versatility

Rinnai HydraHeat™ Hot Water Heat Pumps work great across all climates, even cold ones, because they don't only depend on outdoor temperature changes. This adaptability makes them suitable for a wide range of locations - including everywhere in New Zealand.

6. Low Maintenance

These systems require minimal maintenance, primarily involving occasional checks and cleanings. This ease of maintenance adds to their appeal for both homeowners and businesses.


The Rinnai HydraHeat™  Hot Water Heat Pump stands as a testament to Rinnai's dedication to innovation and sustainability. It not only represents the future of hot water heating technology but also provides homeowners with a practical and eco-friendly solution for their water heating needs.

Getting Started with Rinnai HydraHeat™

If you’re looking for a smarter hot water solution for the homes of tomorrow, here it is.

To find out what makes HydraHeat™ so special, learn more here.

HydraHeat™ Hot Water Heat Pump Installation

For more information on where to buy or to get a quote on getting a HydraHeat™ Hot Water Heat Pump installed at your place, please click here.

To find out more on how a Hot Water Heat Pump works, click here to read our blog article on the Rinnai NZ website.


Related Articles