Rinnai HydraHeat Split Hot Water Heat Pump Operation Guide

Important Information

This hot water system shall be installed in accordance with the manufacturer's installation instructions and current standards including AS/NZS 3000 Electrical Standards, AS/NZS 3500 Plumbing and Drainage Standards, AS/NZS 5149 Refrigerating Systems Operation, and New Zealand Building Code Clause G12 Water Supplies.

The appliance must be installed, commissioned, serviced, and removed by authorised personnel. It is not suitable as a spa or swimming pool heater, nor for hydronic applications.

Warning: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life.

For more information about buying, using, and servicing Rinnai appliances, call: 0800 RINNAI (0800 746 624).

Rinnai New Zealand Limited
105 Pavilion Drive, Mangere, Auckland
PO Box 53177, Auckland Airport, Auckland 2150

Phone: (09) 257 3800
Email: info@rinnai.co.nz
Web: rinnai.co.nz, youtube.com/rinnainz, facebook.com/rinnainz

Contents

This document covers the following topics:

• Safety and important messages
• General information
• About your HydraHeat Split hot water heat pump
• How it works
• Operation modes
• Controller interface
• Maintenance and servicing
• Error codes
• Troubleshooting
• Warranty

For reliable operation, the Rinnai HydraHeat should be serviced every two years. A typical service includes checking/replacing the real-time clock battery, examining/clearing the check valve, cleaning the evaporator, checking/clearing the condensate drain, cylinder connections, and ensuring no water leaks. Regular servicing extends system life.

Safety and Important Messages

This appliance is not intended for use by persons (including children) with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, unless supervised or instructed by a person responsible for their safety. Children should be supervised to ensure they do not play with the appliance.

• DO NOT modify this appliance.
• DO NOT touch power connections.
• DO NOT operate the unit unless the cylinder is full of water.
• DO NOT operate unless all covers are secured and isolating valves are open.
• DO NOT store items on top of or against the unit.
• DO NOT install with incompatible cylinders.
• Avoid touching exposed pipework and fittings as they can be HOT.

Maintain necessary clearances around the unit for continued safe operation.

Warning about hot water

Excessively hot water is dangerous. The Rinnai HydraHeat is set to operate in 'Standard' mode, heating water to a minimum of 60 °C. If installed correctly, the system is equipped with a tempering valve to ensure hot water is delivered at a safe temperature.

Always: Test water temperature with your elbow before placing a child in the bath, and feel the water yourself before bathing or showering. Supervise children in the bathroom. Make sure the hot water tap is turned off.

Consider: Installing child-proof tap covers or child-resistant taps.

Never: Leave a toddler in the care of another child, as they may not understand safe water temperature levels.

Hot pipe work: Care should be taken not to touch pipe work from the cylinder as it can be very hot.

Risk of fire

The unit uses R290 (propane) refrigerant, a class 3 flammable gas according to AS/NZS ISO 817. Only a refrigeration technician with the appropriate license can handle the refrigerant.

• If refrigerant leaks¹, there is a possibility of fire with an external ignition source.
• DO NOT store chemicals or flammable materials near this unit.
• DO NOT place the unit near any ignition sources.
• DO NOT use flammable sprays (e.g., hair spray, spray paint) near this unit as it may cause a fire.

¹ The Rinnai HydraHeat has a sealed refrigerant system; leaks are uncommon unless internal components are punctured. A hissing sound may indicate a leak. Contact your installer or Rinnai immediately if this occurs.

Safety Devices

If installed correctly, your hot water system will be fitted with the following safety devices:

• Temperature & Pressure Relief (TPR) valve on the cylinder to maintain safe pressure and temperature.
• Automatic thermostat to maintain water temperature.
• Temperature override cutout for the heating element.

DANGER: Operation of the thermal cutout can indicate a serious situation. Do not reset it until serviced by a qualified person.

Do not operate the system unless all safety devices are fitted and working. Do not tamper with or remove any safety devices.

Electrical covers: Do not remove the cylinder element cover or the HydraHeat Split electrical cover, as this exposes 230 V wiring. Only an authorised person should remove them.

Damaged components: If any component is damaged, it must be replaced by an authorised person using Rinnai replacement parts.

Hydrogen gas (in enamel cylinders)

If hot water is not used for two weeks or more (e.g., after a holiday), a hot water cylinder with an anode can produce hydrogen gas, which is highly flammable. To remove potential gas buildup, turn on a hot tap for two minutes at a sink, basin, or bath. During this procedure, ensure no smoking, open flame, or other appliance is operating nearby.

Location and positioning

The HydraHeat is designed primarily for outdoor installations. Internal installation may be possible if the location is not an occupied space as defined by AS/NZS 5149. Internally installed units require adequate ventilation due to the appliance's cooling effect and operating noise. Rinnai strongly recommends discussing installation with a qualified installer.

• DO NOT install the unit where it may be exposed to combustible gas leaks, as accumulation may cause a fire.
• DO NOT install the unit where noise may be a nuisance (e.g., near bedrooms or neighbouring properties). Do not place objects on top of the unit, as this can cause vibration and increase noise levels.
• DO NOT install the unit where it will be directly exposed to sea wind and salt spray, as this significantly reduces durability.

Draining and filling the system

This procedure normally occurs during installation or servicing and must be carried out by an authorised person. Draining water from the heat pump unit is necessary if power will be shut off and snow or frost conditions are expected. Arrange for an authorised person to perform this task.

Installation by a licensed tradesperson

Only a licensed tradesperson can install, adjust, maintain, and remove this hot water system. Any work by a non-licensed tradesperson is illegal and voids the warranty.

Legionella

To comply with the NZ Building Code requirement¹ for legionella² disinfection, the system incorporates a built-in disinfection cycle. In this cycle, water in the cylinder is heated above 60 °C for one hour each week, using either the electric element or the heat pump. During legionella disinfection, 'L' will appear on the main display.

¹ Clause G12.3.9, Acceptable Solution G12/AS1 6.14.32
² Legionella is a bacterium that can cause Legionnaires' disease—a severe form of pneumonia.

Cylinder thermostat

The cylinder thermostat is set to 70 °C for 'Element only' mode and disinfection cycles. This setting MUST NOT be adjusted, as any changes will void the warranty.

General Information

The heat pump must be installed upright on a level, stable, and water-impervious base capable of withstanding the system's weight. The structure must not shift. The system is suitable for residential applications only.

Unit orientation

The heat pump is designed for open-air operation, requiring sufficient air supply for efficiency. The air inlet and outlet must be positioned away from prevailing winds and have sufficient clearances as per the installation guide.

Genuine Rinnai parts

Use only included accessories and specified parts for installation. Non-standard parts can cause water leaks, electrical shock, fire, and unit failure.

Defrost function and freeze protection

The HydraHeat has an automatic defrost function to remove ice from the evaporator when the outside air temperature is between -10 °C and 5 °C. 'D' will appear on the display during defrost. Freeze protection activates when temperature sensors detect < 1 °C to prevent pipes from freezing. In Standard and Eco55 modes, this initiates an additional heat pump cycle. In element mode, the circulating pump activates and stops when sensors detect temperatures above 3 °C.

If you live in a frost-prone area and will be away for an extended period with the power supply disconnected, Rinnai recommends having the system drained by an authorised tradesperson to prevent frost damage. Frost damage is not covered by warranty.

Snow zone locations

If prone to snow, the system must be in a covered location. It will not operate effectively if snow builds up around or on top of the appliance.

Disposal guidelines

The heat pump contains refrigerant oil and other potentially hazardous materials. Do not dispose of this system as household waste. Contact Rinnai for more information.

Electrical connection

The heat pump controls the cylinder element via the main PCB. A registered electrician handles electrical installation and termination to the hot water cylinder. It requires an independent, fused AC 230 V 50 Hz power supply. A lockable isolating switch must be installed per AS/NZS 3000 clause 4.19. All electrical work must be done by a licensed electrician per AS/NZS 3000 Wiring Rules.

Note about water / water blasting

The HydraHeat system has an IPX4 rating, protecting against splashing water (e.g., rain). It is not protected from sustained low or high pressure water (e.g., water blasting).

Power supply disruption

If power is lost, the system retains all settings (day, time). Upon restoration, it resumes normal operation in the previously set mode.

Condensation

Condensation occurs as air across the evaporator is cooled. In high humidity, large volumes can be generated. The installer must ensure condensate is plumbed to a suitable drain from the unit's bottom hole.

R290 refrigerant

R290 refrigerant (propane) is praised for its positive environmental aspects, including low global warming potential (GWP) and zero ozone depletion potential (ODP). R290 is a natural hydrocarbon with minimal environmental impact and is energy-efficient, leading to lower energy consumption and operational costs.

About your HydraHeat Split hot water heat pump

We hope you love this product. If something goes wrong or you need help, Rinnai is a phone call away.

Designed and assembled in New Zealand

Designed and manufactured in NZ to operate efficiently in NZ climates with a wide temperature range of -10 °C to 42 °C.

Sleek Cod Grey

Features a grey powder-coated design with a permissible LRV¹, suitable for installation in areas like Queenstown.

Easy to use controls

A user-friendly control interface ensures convenience and ease of use.

Split design

Offers installation flexibility, allowing the heat pump unit to be connected to a new or existing cylinder², which can be located indoors or outdoors.

¹ LRV - light reflectance value.
² Must comply with cylinder compatibility criteria.

Low operating noise

An ideal choice for built-up residential areas due to its low operating sound level of 48 dB(A), making it one of the quietest options available.

Energy efficient performance and natural R290 refrigerant

The HydraHeat Split boasts an impressive coefficient of performance (COP) of 4.6, resulting in highly efficient water heating that minimises energy consumption and lowers operating costs. R290, with a 150 g charge, is a natural hydrocarbon refrigerant offering minimal environmental impact, while the reduced charge ensures system safety.

How it works

A heat pump transfers heat from ambient outside air into water. Electricity powers the compressor but does not directly heat the water, significantly reducing energy consumption compared to a traditional electric hot water cylinder. The warmer the climate, the more efficient the system.

1. Ambient air is blown through the evaporator.
2. Heat from the ambient air is transferred onto the refrigerant.
3. Refrigerant is compressed and becomes hot.
4. Hot refrigerant passes through the heat exchanger and transfers heat to the cold water, making it hot.

Diagram Description: A schematic shows air entering an evaporator, then a compressor, expansion valve, and heat exchanger. Refrigerant circulates through these components. Water enters cold, passes through the heat exchanger, and exits hot, connecting to an electric cylinder. A fan draws air through the evaporator.

The control panel displays the current operational mode:

• Standard: Water heated to, and delivered to the cylinder at 60 °C.
• Eco 55: Water heated to, and delivered to the cylinder at 55 °C.
• Element only: Heat pump off; cylinder element heats water to thermostat setting (should be 70 °C¹).
• Shutdown: In standby; heat pump and element are turned off.

¹ Required for operation and compliance of Legionella disinfection.

Operation modes

The heat pump unit is preset to operate in 'Standard' mode, heating water to at least 60°C before delivering it to the cylinder.

Eco 55

This is a cost-saving mode where the system continually heats water to 55 °C by the heat pump before delivering it to the cylinder.

Element only

Water in the cylinder is heated solely by the electric element; the heat pump does not run. This mode is used if there is a system fault¹ or if the homeowner wishes to prevent heat pump activation at night due to noise (via timer setting). It still allows hot water availability.

Note: When a fault occurs, the system automatically switches to 'element only' mode until the issue is resolved. It will revert to its previous operating mode once fixed.

Shutdown

The system is completely off and in standby mode, ideal for holidays or to prevent heat pump activation at night due to noise. When switched back on, it may take 4–8 hours to reheat the water, depending on ambient air temperature.

Important: When the heat pump is operating, it runs at slightly lower temperatures than a traditional cylinder. If high volumes of hot water are used, this may result in a reduced amount of available hot water. The installer is responsible for ensuring the hot water system is sized correctly.

Note: We do not recommend switching the system off (without power connected) in areas where frost could occur or in the middle of winter. Damage to the system if not continually connected to the electricity supply is not covered by warranty.

¹ If a fault occurs, an error code will appear on the display and the unit will beep. Refer to page 13 for more information. If there is a main PCB error, there will be no hot water. An electrician can bypass the system to restore power directly to the heating element if the fault cannot be rectified quickly.

² Under extremely low ambient air conditions, the element may be briefly used to complete the legionella disinfection heating cycle.

³ Element will be used for the legionella disinfection cycle.

Controller interface

The HydraHeat controller uses a compact OLED display with three capacitive touch buttons for easy menu access. A button press produces an audible beep.

Home screen and navigation

To access the home screen, press OK for approximately 3-5 seconds. The screen shows the current operating mode, set to 'Standard' by default. The display turns off automatically after 30 seconds but can be reactivated by pressing any button.

Diagram Description: A controller screen displays 'STANDARD TEMP 60°C HP ON ELEMENT'.

Button functions:

• OK: Selects the option.
• V (Down): Scrolls through menu options.
• < (Back): Returns to the previous screen.

Operation modes

Press the Down button (V) to cycle through screens and select the desired operation mode. Press OK to confirm. The selected mode will be displayed.

Diagram Description: A sequence of controller screens shows how to navigate to select modes like STANDARD, ECO 55, ELEMENT ONLY, and SHUTDOWN, with OK and V/< buttons used for navigation and selection.

Day and time

This setting is only needed during daylight savings or if factory settings are lost (e.g., after a 'Factory reset'). The clock is a 24-hour clock. Once in 'Set Day / Time', press and hold the Down button (V) to scroll through day, hour, and minutes to edit, pressing OK to confirm each stage.

Set and forget timer

The timer can lock out system operation during programmed times until 'Timer Reset' is selected. This is useful for reducing noise at night.

How to set

1. Select 'SET TIMER', and press OK.
2. Press and hold the Down button (V) to scroll through hours/minutes to edit, and press OK.
3. Once the time is set, select the mode of operation using the Down button (V), and press OK to confirm.

Diagram Description: Controller screens show setting the START TIME (e.g., 22:00) and END TIME (e.g., 06:00) with the MODE set to SHUTDOWN.

Important: Activated timers can prevent system operation, potentially leading to insufficient or no hot water, depending on usage.

Reset timer

1. Select 'SET TIMER', and press OK.
2. Use the Down button (V) to select ‘RESET TIMER', and press OK.
3. Confirm 'YES', and press OK.

Diagram Description: Controller screens show selecting 'SET TIMER', then 'RESET TIMER', and confirming with 'YES'.

Factory reset

Diagram Description: Controller screens show selecting 'FACTORY RESET' and confirming with 'YES'.

A factory reset clears the date, time, and set timers, retaining only the default 'STANDARD' mode setting. After a factory reset, you will need to reconfigure the date and time for timer functionality.

Locking / Unlocking the screen

To lock the screen, press and hold both the OK and Back (<) buttons for more than five seconds. The screen will display 'Locked' and return to the current operation mode. To unlock and access the main menu, press and hold the same two buttons again.

Diagram Description: A controller screen shows 'LOCKED HP ON ELEMENT' with an indicator for '5 secs OK + <'.

Maintenance and servicing

For reliable operation, the Rinnai HydraHeat should be serviced every two years. A typical service includes checking/replacing the real-time clock battery, examining/clearing the check valve, cleaning the evaporator, checking/clearing the condensate drain, cylinder connections, and ensuring no water leaks. Regular servicing extends system life.

¹ In hard water areas, the element must be periodically descaled. To do this, the cylinder must be drained and the element removed.

TPR valve

This valve is located near the top of the cylinder and is essential for safe operation. It automatically vents hot water if the temperature or pressure becomes too high. Every six months, operate the easing gear to remove lime deposits and check for blockages. Easing the lever discharges hot water; ensure no one is near the drain line.

Warning: Failure to operate the relief valve easing gear at least once every six months may result in the water heater exploding.

Continuous leakage of water from the valve may indicate a problem. Raise and lower the easing gear GENTLY. If the valve does not discharge water when lifted, or does not seal when closed, arrange for an authorised person to inspect the system immediately.

Important: During servicing, the TPR valve needs to be checked and/or replaced by an authorised person at intervals not exceeding five years, or more frequently in hard water areas. A TPR valve must not be replaced with one having a higher pressure rating than specified for the cylinder.

Anodes in enamel tanks

Storage tanks made from enamel can be susceptible to corrosion. Anodes are placed in enamel tanks to corrode first. Anodes should be changed every five years, or more frequently in hard or aggressive water areas.

Clearing debris and pooling water

Ensure water does not pool around the heat pump, and that debris around the system is regularly cleared and does not build up.

Regular visual inspection

Regularly check your system for buildup around or on top of the unit, and for water leaks. Keep the exterior clean.

Rinnai has a maintenance, service, and spare parts network with trained personnel. Regular maintenance and servicing are not covered by the Rinnai warranty.

For help locating a service person, call 0800 RINNAI (0800 746 624).

Diagram Description: A diagram shows the TPR valve position at the top of a cylinder and illustrates how to operate the easing gear: GENTLY lift until water flows from the drain line, then lower GENTLY to release.

Error codes

When the system encounters an error, an error code (e.g., S6) displays on the screen, the unit beeps every 5 seconds, and the system automatically enters 'Element Only' mode until the fault is fixed. 'Element Only' mode ensures a continued hot water supply.

Note the error code and contact Rinnai or your installer.

Diagram Description: A controller screen shows 'FAULT S6 HP ON ELEMENT'.

Important: 'Element Only' mode means water is heated only by the electric element. If not addressed quickly, this may result in a larger than normal power bill.

To mute the error code beep, press and hold the Back button (<) for three seconds.

Troubleshooting

Do not attempt work other than what is described in this section. For other faults, contact your installer or Rinnai.

Limited Warranty - HydraHeat Split

Rinnai HydraHeat Split warranty summary

All warranty terms are effective from the first date of installation; proof of installation is required. If the installation date is unknown, warranty is based on the manufacture date. Claims must be made within a reasonable time of fault discovery. The HydraHeat Split is for residential applications only.

General warranty terms

Rinnai reserves the right to modify specifications and parts without notice. For the Consumer Guarantees Act 1993 purposes, Rinnai guarantees repair facilities and spare parts availability for express warranty periods. If acquired for personal, domestic, or household use, this warranty does not limit consumer rights under the Act. If acquired for business purposes, the Act's provisions do not apply, and only stated warranties apply.

*A residential application is defined as an installation delivering hot water to a single-family dwelling, not used for commercial purposes (e.g., hair salon, catering kitchen). An accommodation business like a motel serving a single-family dwelling equivalent is considered residential.

Warranty terms and conditions

• All warranty terms are effective from the date of first installation. The attending service person may verify this date.
• The Rinnai HydraHeat Split system must be installed, commissioned, serviced, repaired, and removed according to manufacturer instructions, local regulations, and municipal building codes by authorised persons.
• All appliances must be operated and maintained per manufacturer instructions. For reliable operation, service every two years is recommended.
• This warranty applies only to Rinnai-supplied components, not those supplied by others (e.g., valves, switches, pipework, cables, fuses, hot water cylinder).
• If the appliance is not sited correctly or service access is difficult, a service charge will apply. If installation is deemed illegal or access dangerous, service may be refused. Work required to gain access (e.g., wall removal, special equipment) is chargeable.
• If a failed component is replaced under warranty, the balance of the original appliance warranty remains effective. The replacement part/appliance does not carry a new warranty.
• Rinnai may transfer functional components from defective appliances if suitable.
• Rinnai may require product return for inspection.
• The decision to repair or replace a faulty component is at Rinnai's sole discretion.
• If Rinnai determines the unit needs removal for repair, they may replace it with a substitute unit of equal or better condition.
• This warranty covers only the heat pump and connection kit.
• Water quality must meet specified limits (refer page 18).
• For installations outside the metropolitan area or further than 40 km from a Rinnai authorised service centre, travel costs are the owner's responsibility.

Warranty exclusions

The following exclusions may void the warranty and incur service/parts charges:

• Accidental damage, defects, or failure caused by acts of nature (fire, wind, lightning, flood, storm, hail, vandalism, earthquake, war, civil unrest, pests, animals, insects) or entry of foreign objects (dirt, debris, moisture).
• Faults from the manufacturing of the hot water cylinder.
• Defects or failure due to environmental damage (e.g., corrosion).
• Failure due to abuse, misuse, improper maintenance, or improper storage.
• Failure due to incorrect or unauthorised installations.
• Failure or damage from alterations, service, or repair by non-authorised persons.
• Hot water cylinders are not covered, as the heat pump does not compromise their integrity.
• Failure due to poor water quality outside specified limits (refer next page).
• Situations where no fault exists with the appliance, but the issue relates to installation or power failure.

Rinnai does not accept liability for:

• Consequential damage or incidental expenses from warranty breach.
• Claims for damage to buildings or other consequential loss due to leaks or other faults.

Water quality

Water chemistry impacts hot water heaters, affecting corrosion protection and causing scale buildup.

Water quality MUST:

1. Meet the Water Services (Drinking Water Standards for New Zealand) Regulations 2022 and the Aesthetic Values for Drinking Water Notice 2022, or equivalent statutory standards.
2. Be within the limits shown in the table below.

Water quality outside these limits will void this warranty.

Water quality and impurity limits

¹ Langelier Saturation index—scaling potential of water.

Water quality warranty guidelines

Filtration

If discolouration, debris, or silt is present, an inline filter must be fitted to protect the copper in the heat pump unit from corrosion. Particulates and deposits are corrosive to copper and stainless steel, leading to premature pitting. Filters must be periodically replaced.

Stagnation

Leaving water stagnant promotes corrosion. If the system is not in use, flush it on an eight-week cycle.

Bore and tank water

Bore and tank water supplies should be considered corrosive and tested prior to use. Bore and tank water must meet the water quality parameters stated above.

Purchase details

Record your purchase details below.

Retailer:
_________________________

Retailer address:
_________________________

Date of purchase:
_________________________

Product details:
_________________________

Please keep these details in a safe place for future reference.

ATTACH YOUR PROOF OF PURCHASE HERE:

Register your system online: www.rinnai.co.nz/register/ for service reminders, product updates, and special offers. You can unsubscribe at any time.

Installer details

Company name: _________________________

Installer name: _________________________

Address: _________________________

Phone: _________________________ Mobile: _________________________

Signed: _________________________ Date: _________________________

Contact Information

Rinnai.co.nz

Tel: 0800 746 624

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Rinnai HydraHeat Split operation guide 31453-C