Rinnai HydraHeat® Split
Hot Water Heat Pump using existing HWC

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

This energy-efficient split hot water heat pump is eligible for an NZ Green Energy Loan – read here for more information.

Combining Rinnai’s expertise in water heating and heat pump technology, the HydraHeat® Split Hot Water Heat Pump offers a highly efficient way to heat your water. Its split design allows flexible installation while maximising performance.
How It Works
Operating much like a refrigerator in reverse, the HydraHeat ® Split utilises the surrounding air’s
ambient temperature and amplifies this energy to heat water at significantly reduced costs and then
transfers this hot water into your cylinder.

Top-Down Heating with Stratification – Instead of heating the entire volume of water uniformly, the
system prioritises heating the top layer of water first. Hot water, being less dense, naturally rises to the
top of the storage cylinder and cooler water stays at the bottom, allowing the heat pump to continue
heating efficiently.

Because the top portion of the cylinder reaches the set temperature quickly, hot water is available for
use sooner—even while the lower layers are still heating.

Thanks to this stratification effect, the HydraHeat® Hot Water Heat Pump quickly provides hot water
from the top down, ensuring an energy-efficient and reliable option for Kiwi households.

The Rinnai HydraHeat® Split Hot Water Heat Pump utilises thermal stratification within the storage cylinder to ensure rapid hot water delivery from the moment it starts, offering an efficient and practical water heating solution.

Up to 75% Savings on Hot Water Costs*

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

Dedicated to Sustainability

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

Renowned Quality

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

HydraHeat® head unit designed and built in NZ

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.

Reliability

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

Modular ‘Heat Pump Ready’ Design

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

Easy Servicing

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

Frost Protection

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

NZ MEPS Compliant

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.

User Friendly Control Interface

Features OLED screen and six operation modes for versatility.

Six Operation Modes

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

Ideal for a Range of Residential Styles

Suitable for homes of 2–6 people. Plus an operating sound level of only 45dBA makes it suitable for a wide range of homes, including built-up residential areas.

* Compared with a standard hot water cylinder in Zone 5 (Auckland). Annual energy performance estimated according to AS/NZS4234:2008 and AS/NZS5125:2014, medium load size.
** Inlet water temperature 19°C, Outlet Water temperature 55°C, Dry Bulb Temperature 19°C. Accredited Testing to AS/NZS 5125 Pending by NATA accredited Provider.

Rinnai Hydraheat® Split product page
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