AquaMAX HP325-36-1B Series Technical Document

This water heater must be installed and serviced by a qualified person.
Please leave this guide with the householder.
Owner’s Guide
and
Installation Instructions
Air Sourced Heat Pump
Water Heater
HP325-36-1B Series

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Warning: Upon completion of the installation and commissioning of the water heater, leave this guide
with the householder or responsible officer. DO NOT leave this guide inside the cover of the water heater or
the heat pump module, as it may interfere with the safe operation of the water heater or ignite when the
water heater is turned on.
Patents
This water heater may be protected by one or more patents or registered designs in the name of
Aquamax Australia Pty Ltd or Rheem Australia Pty Ltd.
Trade Marks
®Registered trademark of Aquamax Australia Pty Ltd. or Rheem Australia Pty. Ltd.
™ Trademark of Aquamax Australia Pty Ltd or Rheem Australia Pty Ltd.
Note: Every care has been taken to ensure accuracy in preparation of this publication. No liability can be
accepted for any consequences, which may arise as a result of its application.

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CONTENTS
Householder: Read the section “About Your Water Heater”(pages 3 to 15). The “Installation” section is
intended for the installer but may be of interest.
ABOUT YOUR WATER HEATER ......................................................................................................................3
Model Type .................................................................................................................................................... 3
Timer Control ................................................................................................................................................. 4
Turning On the Water Heater ........................................................................................................................ 4
To Turn Off the Water Heater........................................................................................................................ 5
Temperature Adjustment ............................................................................................................................... 5
Other Important Information........................................................................................................................... 5
Periodic Maintenance .................................................................................................................................... 6
Water Chemistry............................................................................................................................................ 8
Troubleshooting ........................................................................................................................................... 10
Operating Mode Monitor LED Indication...................................................................................................... 14
INSTALLATION................................................................................................................................................16
Installation Overview.................................................................................................................................... 16
Water Supplies............................................................................................................................................. 17
INSTALLATION –COMPONENTS ............................................................................................................. 18
Water Heater Location............................................................................................................................. 18
Heat Pump Module & Storage Cylinder Assembly .................................................................................. 18
INSTALLATION –PLUMBING & PLUMBING CONNECTIONS ................................................................. 20
Heat Pump Plumbing & Plumbing Connections ...................................................................................... 20
General Plumbing Arrangement & Plumbing Diagrams .......................................................................... 22
Two Temperature Zones Using a Temperature Limiting Device............................................................. 22
Circulated Hot Water Flow & Return Systems......................................................................................... 23
INSTALLATION –ELECTRICAL & ELECTRICAL CONNECTIONS .......................................................... 24
Heat Pump Electrical & Electrical Connections ....................................................................................... 24
Booster Thermostat Adjustment .............................................................................................................. 24
Wiring Diagram ........................................................................................................................................ 25
COMMISSIONING....................................................................................................................................... 26
To Fill & Turn On the Water Heater ......................................................................................................... 26
Draining the Water Heater........................................................................................................................... 27
Dimensions & Technical Data...................................................................................................................... 28
WARRANTY.....................................................................................................................................................29

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ABOUT YOUR WATER HEATER
Water Heater Application
This water heater is designed for use in a single family domestic dwelling for the purpose of heating potable
water. Its use in an application other than this may shorten its life.
Warning: This water heater is only intended to be operated by persons who have the experience or the
knowledge and the capabilities to do so. This water heater is not intended to be operated by persons with
reduced physical, sensory or mental capabilities i.e. the infirm, or by children. Children should be supervised
to ensure they do not interfere with the water heater.
Model Type
Your Aquamax®air sourced heat pump water heater is designed for outdoor installation only. The model you
have chosen is a HP325-36-1B and is recommended for connection to a minimum 16 hour per day power
supply.
An Aquamax heat pump water heater consumes less energy than an electric water heater. The impact on an
electricity account will depend on the tariff arrangement of the water heater replaced and where you live.
Contact your energy provider for more information on tariff arrangements and cost comparisons.
Model Selection Chart
The model number shown below applies to the heat pump water heater which is made of two main
components, the storage cylinder and heat pump module.
325 Litre
HP325-36-1B
Note: All models can be supplied with a „Hard Water Anode‟. These models have the suffix „HWA‟ at the end of
the model number of the storage cylinder component.
Legend
HP325
Heat Pump storage cylinder capacity in litres 240V AC, 50Hz
36
Element wattage (3600W)
1B
One B series heat pump module
Heat Pump Operation
Water is stored in a vitreous enamel lined steel cylinder. The water heater‟s evaporator absorbs heat from
the surrounding air and transfers this heat into the water in the storage cylinder.
When hot water is drawn off and cold water enters the storage cylinder, the controller activates a fan, a
compressor and a circulating pump. The fan draws outside air in through the air inlet louvres at the side of
the heat pump module and the circulating pump circulates water from the bottom of the storage cylinder
through the heat exchanger. Heat is absorbed from the surrounding air by an evaporator and transferred into
the water flowing through the heat exchanger. The resulting cold air is then discharged through the air outlet
grille back to atmosphere and the heated water is circulated back into the storage cylinder. This process
continues while heating is required until the water in the storage cylinder reaches a temperature of 60°C.
Even on cloudy or cold days, heat is drawn from the surrounding air. The heat pump will operate when the
ambient air temperature is between a minimum of 3°C to 5°C and a maximum of 45°C to 55°C. The electric
booster (heating unit or element) will operate when the ambient air temperature is outside of this temperature
range if heating is required. The efficiency of the water heater increases as the ambient air temperature
increases within the operating range of the heat pump.
Automatic safety controls are fitted to the water heater to provide safe and efficient operation.
Electric Booster Operation
If the ambient air temperature falls below 7°C and the heat pump has been operating for an extended period,
ice may begin to form on the evaporator reducing heat pump efficiency. At ambient air temperatures below
3°C to 5°C, the water heater will deactivate heat pump operation and switch to booster heating mode. When
operating in booster heating mode the water in the storage cylinder is heated by the booster heating unit to a
temperature of 70°C and the evaporator will defrost if necessary.
At ambient air temperatures above 45°C to 55°C, the water heater will deactivate heat pump operation and
switch to booster heating mode to protect the heat pump from overheating. When operating in booster

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heating mode, the water in the storage cylinder is heated by the booster heating unit to a temperature of
70°C.
If the heat pump detects certain fault conditions, the water heater will deactivate heat pump operation and
switch to backup heating mode to ensure a supply of hot water. When operating in backup heating mode the
water in the storage cylinder is heated by the booster heating unit to a temperature of 70°C.
The boost capacity of a HP325-36-1B model heat pump when operating in boost or backup heating mode is
206 litres.
Mains Pressure Operation
The water heater is designed to operate at mains pressure by connecting directly to the mains water supply.
If the mains supply pressure in your area exceeds that shown in “Mains Water Supply” on page 17 a
pressure limiting valve must be fitted. The supply pressure should be greater than 350 kPa for true mains
pressure operation to be achieved. A minimum water supply pressure of 200 kPa is required to enable the
heat pump circulator and heat pump system to operate effectively.
High Hot Water Temperature Increases the Risk of Scald Injury
Warning: This water heater can deliver water at temperatures which can cause scalding. Always check
the water temperature before use, such as when entering a shower or filling a bath or basin, to ensure it is
suitable for the application and will not cause scald injury. Aquamax recommends monthly temperature
checks to ensure the appropriate temperature is maintained within the hot water heater.
Aquamax recommends, and it may also be required by regulations, that a secondary device such as an
approved temperature limiting device or anti-scald water shut off valve be fitted into the hot water pipe work
to the bathroom(s) and ensuite(s) if persons living in the house require additional safety protection from
potential scalding. This will keep the hot water supply temperature to the bathroom(s) and ensuite(s) below
50°C which will reduce the risk of scald injury whilst still allowing hotter water (60°C+) to the kitchen and
laundry.
For new hot water installations, all sanitary outlet fixtures used primarily for personal hygiene purpose must
deliver hot water not exceeding 50°C. This temperature limit is not mandatory for kitchen sinks and laundry
tubs.
To minimise scalding, especially for those people in high scald risk categories i.e. young children, people
with potentially incapacitating medical conditions, elderly people etc, this water heater must be installed in
accordance with AS/NZS 3500.4.
For early childhood centres, primary and secondary schools, nursing homes or similar facilities for young,
aged, sick or disabled persons, please consult your local health authority for the correct temperature setting.
Timer Control
A timer can be installed in the electrical circuit to the water heater. The timer must be weatherproof if it is
installed outdoors.
It may be desirable for the water heater not to operate between certain hours, such as during the peak
period when connected to a “Time of Use”electricity supply due to a more expensive tariff rate applying.
A timer will affect the operating times of both the heat pump circuit and the booster heating unit.
Note: The HP325-36-1B model water heater is recommended for connection to a minimum 16 hour per day
power supply.
Turning On the Water Heater
To turn on the water heater:
1. Fully open the cold water isolation valve at the cold water inlet to the water heater.
2. Switch on the electrical supply at the isolating switch to the water heater.
Note: When power is turned on or reconnected to the water heater, the red LED will emit a solid glow for
three (3) seconds and then extinguish. This is normal operation and does not indicate a fault. The LED
display will then return to the current operational status.
The water heater may take up to forty five (45) minutes to commence operating when the power supply is
switched on. The heat pump will only operate when power is available at the water heater, the water in the

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storage cylinder requires heating, the heat pump compressor is cool and the ambient air temperature is
within the heat pump‟s operating temperature range of between a minimum of 3°C to 5°C and a maximum of
45°C to 55°C. If the ambient temperature is outside of this range, the water heater will commence heating
with the booster heating unit.
When the heat pump is operating, the system will switch to the booster heating unit if the detected ambient
air temperature is outside the operating temperature range of between a minimum of 3°C to 5°C and a
maximum of 45°C to 55°C.
The system will not switch back to heat pump operation from the booster heating unit if the detected ambient
air temperature has moved back within the heat pump‟s operating temperature range. The heating cycle will
be completed by the booster heating unit.
Note: The heat pump may not turn on after either having just completed a heating cycle and more hot water
is drawn from the water heater or power is shut down to the compressor, either during or at the end of a
heating cycle. The heat pump will wait until the compressor has cooled down and the conditions for start up
are favourable in order to protect the compressor from damage. This will be a minimum of forty five (45)
minutes and may take up to ninety (90) minutes from the last heating cycle.
To Turn Off the Water Heater
If it is necessary to turn off the water heater:
1. Switch off the electrical supply at the isolating switch to the water heater
2. Close the cold water isolation valve at the cold water inlet to the water heater.
Temperature Adjustment
The thermostat controlling the heat pump and the electric booster are factory set and are not adjustable.
Other Important Information
Going Away?
If you plan to be away from home for one or two nights, we suggest you leave the water heater switched on.
However, If you plan to stay away more than a few nights, conserve energy by switching the water heater off
at either the switchboard or isolating switch (if fitted) (refer to “To Turn Off the Water Heater”on page 5).
Refer to “Turning On the Water Heater” on page 4 for notes regarding water heater restarting after being
shut down.
Safety
This water heater is supplied with a thermostat, two over temperature energy cut outs and a combination
temperature pressure relief valve. These devices must not be tampered with or removed. The water heater
must not be operated unless each of these devices is fitted and is in working order.
The operation of the over temperature cut out on the thermostat indicates a possibly dangerous situation. If
the over temperature cut out operates, it must not be reset and the water heater must be serviced by a
qualified person.
If the electrical supply conduit to the water heater is damaged, it must be replaced by a qualified person in
order to avoid a hazard. Phone Aquamax Service or their nearest Accredited Service Agent to arrange for an
inspection.
The Aquamax warranty may not cover faults if relief valves or other safety devices are tampered with or if the
installation is not in accordance with these instructions.
Warning: For continued safety of this water heater it must be installed, operated and maintained in
accordance with the Owner’s Guide and Installation Instructions. These instructions must be read in
conjunction with all other instructions affixed to the appliance and the installation instructions supplied with
the heat pump module.
Warning: Do not use aerosols, stain removers and household chemicals near the water heater
whilst it is operating. Gases from some aerosol sprays, stain removers and household chemicals are
flammable and/or become corrosive to the materials used in the heat pump system.
Warning: Do not store swimming pool chemicals, household cleaners, etc., near the water heater.

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Warning: Ensure the air flow, air inlet louvres and outlet grille are not obstructed in any way at any time.
Warning: This water heater uses 240 V AC electrical power for operation of the control systems and the
electrically operated components. The removal of the access cover(s) will expose 240 volt wiring. They must
only be removed by a qualified person.
How Long Will The Water Heater Last?
The water heater is supported by a manufacturer‟s warranty (refer to page 29). There are a number of
factors that will affect the length of service the water heater will provide. These include but are not limited to
the water chemistry, the water pressure, the water temperature (inlet and outlet) and the water usage
pattern.
Environment
At the end of the service life of the heat pump water heater and prior to the water heater being disposed of, a
person qualified to work with refrigerants must recover the refrigerant from within the sealed system. The
refrigerant must not be vented to atmosphere. Phone Aquamax Service or their nearest Accredited Service
Agent to arrange for an inspection.
Precautions
Where damage to property can occur in the event of the water heater leaking, the water heater must be
installed in a safe tray. Construction, installation and draining of a safe tray must comply with AS/NZS 3500.4
and all local codes and regulatory authority requirements.
The water heater must be maintained in accordance with the Owner‟s Guide and Installation Instructions.
Refer to “Periodic Maintenance”on page 6.
If this water heater is to be used where an uninterrupted hot water supply is necessary for your application or
business, you should ensure that you have back up redundancy within the hot water system design. This
should ensure the continuity of hot water supply in the event that this water heater was to become inoperable
for any reason. We recommend you seek advice from your plumber or specifier about your needs and
building back up redundancy into your hot water supply system.
Periodic Maintenance
Minor Six Monthly Maintenance
It is recommended minor maintenance be performed every six months by the dwelling occupant.
Warning: Exercise care when operating easing levers as water discharged from the water heater may
be of a very high temperature.
Minor maintenance actions:
1. Operate easing lever on the pressure temperature relief valve (refer to “Pressure Temperature Relief
Valve” on page 7).
2. Operate easing lever on expansion control valve (if ECV fitted) (refer to “Expansion Control Valve” on
page 7).
3. If a safety tray is installed, check to ensure the safety tray drain pipe is not blocked.
Major Five Year Service
It is recommended a major five year service be conducted on the water heater.
Servicing must be performed by a qualified person. Phone Aquamax Service or their nearest Accredited
Service Agent.
Note: The five year service and routine replacement of any components, such as the anode and relief
valves, are not included in the Aquamax warranty. A charge will be made for this work.
Major five year service actions:
1. Replace pressure temperature relief valve.
2. Inspect and flush expansion control valve (if fitted) and replace expansion control valve if required.
3. Inspect and if required, replace the anode. If the anode is not replaced, it should be replaced within
three years of this service (refer to “Anode” on page 7).

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4. Check the electric heating unit for excessive calcium build up or corrosion and replace heating unit if
required.
5. Check and inspect the heat pump module for operation.
6. Visually check the unit for any potential problems.
7. Inspect all plumbing and electrical connections.
8. Check the condensate drain to ensure it is not blocked.
9. If a safety tray is installed, check to ensure the safety tray drain pipe is not blocked.
Note: The water heater may need to be drained during this service. When switched back on, the water
heater will take some time to reheat the water. Depending upon the power supply connection, hot water may
not be available until the next day.
Heat Pump System
It is recommended the evaporator and refrigeration system is checked every five years. In particularly dusty
environments, it may be necessary to have the heat pump system checked and cleaned of dust and residue
on a more regular basis.
Pressure Temperature Relief Valve (PTR Valve)
The PTR valve is near the top of the storage cylinder and is essential for safe operation. It is possible for the
PTR valve to release a little water through the drain line during each heating period. This occurs as the water
is heated and expands by approximately 1/50 of its volume.
Continuous leakage of water from the PTR valve and its drain line may indicate a problem
with the water heater (refer to “Pressure Temperature Relief Valve Running” on page 12).
Warning: Never block the outlet of the PTR valve or its drain line for any reason.
Operate the easing lever on the PTR valve once every six months. It is very important
you raise and lower the lever gently.
Warning: Exercise care when operating easing leaver as water discharge from the water heater may be
of a very high temperature.
Warning: Exercise care to avoid any splashing of water, as water discharged from the drain line will be
hot. Stand clear of the drain line’s point of discharge when operating the valve’s lever.
Danger:Failure to perform this procedure may result in the water heater storage cylinder failing, or
under certain circumstances, exploding.
If water does not flow freely from the drain line when the lever is lifted, then the water heater must be
checked. Phone Aquamax Service or their nearest Accredited Service Agent to arrange for an inspection.
The pressure temperature relief valve should be replaced at intervals not exceeding 5 years, or more
frequently in areas where there is a high incidence of water deposits (refer to “Water Chemistry” on page 8).
Expansion Control Valve (ECV)
In many areas, including South Australia, Western Australia and scaling water areas, an ECV is fitted to the
cold water supply line to the water heater (refer to the “Cold Water Supply Plumbing Arrangement” diagram
on page 20). The ECV may discharge a small quantity of water from its drain line during the heating period
instead of the PTR valve on the water heater.
Operate the easing lever on the expansion control valve once every six months. It is very important you
raise and lower the lever gently.
The expansion control valve should be checked for performance or replaced at intervals not exceeding
5 years, or more frequently in areas where there is a high incidence of water deposits (refer to “Water
Chemistry” on page 8).
Anode
The anode installed in your water heater has been designed to slowly dissipate whilst protecting the storage
cylinder. If the water heater is not used for two (2) weeks or more, a quantity of hydrogen gas, which is highly
flammable, may accumulate in the water heater. To dissipate this gas safely, it is recommended that a hot
tap be turned on for several minutes or until discharge of gas ceases. Use a sink, basin, or bath outlet, but

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not a dishwasher, clothes washer or other appliance. During this procedure, there must be no smoking, open
flame, or any electrical appliances operating nearby. If hydrogen is discharged through the tap, it will
probably make an unusual sound similar to air escaping.
The life of the storage cylinder may be extended by arranging a qualified person to periodically inspect the
anode and replace if required. If the anode is not replaced during a five year service (refer to “Major Five
Year Service” on page 6) then the maximum time after installation when the anode should be replaced for
this water heater is 8 years.
For water supplies which are either softened, desalinated or where the water supply may alternate between
a water tank and a reticulated public supply or another supply, it is recommended the anode be replaced
within 5 years of installation.
Change of Water Supply
The changing or alternating from one water supply to another can have a detrimental effect on the operation
and / or life expectation of a number of components in this water heater.
Where there is a changeover from one water supply to another, e.g. a rainwater tank supply, bore water
supply, desalinated water supply, public reticulated water supply or water brought in from another supply,
then water chemistry information should be sought from the supplier or it should be tested to ensure the
water supply meets the requirements given in these guidelines for the Aquamax warranty to apply.
Water Chemistry
This water heater must be installed in accordance with this advice to be covered by the Aquamax
warranty.
This water heater is manufactured to suit the water conditions of most public reticulated water supplies.
However, there are some known water chemistries which can have detrimental effects on the water heater
and its operation and / or life expectancy. If you are unsure of your water chemistry, you may be able to
obtain information from your local water supply authority. This water heater should only be connected to a
water supply which complies with these guidelines for the Aquamax warranty to apply.
Total Dissolved Solids (TDS)
Some water analysis reports may state the conductivity of the water rather than the level of total dissolved
solids. Conductivity, measured in microsiemens per centimetre (µS / cm), is directly proportional to the TDS
content of the water. TDS, in mg / L, is approximately 70% of the conductivity in µS / cm.
The Aquamax warranty will not cover resultant faults to the storage cylinder if this water heater is connected
at anytime to a water supply where the TDS content of the water exceeds 600 mg/L. In locations where the
water supply TDS exceeds 600 mg/Litre, the magnesium alloy anode (supplied as standard, cap colour
code „Black‟) should be replaced with an aluminium alloy anode (cap colour code „Blue‟). For more
information refer to “Water Chemistry & Anode Type” on page 8.
In locations where TDS approaches 600 mg/L, e.g. due to sediment, we strongly recommend fitting an
appropriate filter to ensure water entering or in the water heater does not exceed this level at any time i.e.
due to sediment build up.
Water Chemistry & Anode Type
Aquamax water heaters are designed to suit the water conditions of most metropolitan supplies, where the
Total Dissolved Solids (TDS) content of the supply is less than 600 mg/Litre. For use in regions where the
water supply TDS exceeds 600 mg/Litre, the magnesium alloy anode (supplied as standard, cap colour code
„Black‟) may become excessively reactive. For safety reasons and the longevity of the anode, the
magnesium anode should be replaced with an aluminium alloy anode (cap colour code „Blue‟) available from
your Aquamax supplier. Anode replacement must be carried out by an Aquamax accredited service agent.
Warning: If the water supply has a TDS greater than 600 mg/L and the anode has not been changed to
a blue anode, there is the possibility the anode may become overactive and hydrogen gas could accumulate
in the top of the water heater during long periods of no use.
If the water heater has not been used for two or more weeks, follow the procedure detailed in the “Anode”
section on page 7 for safe dissipation of the hydrogen gas build up inside the storage cylinder.
It must be noted that in areas where the TDS exceeds 600 mg/Litre, the Aquamax warranty will not cover
resultant faults on components including the storage cylinder that fail due to the bad water conditions even

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though an aluminium anode is fitted. Refer to “Water Chemistry Levels Affecting Warranty” on page 9 for
water chemistry levels and components affected.
The life of the water heater may also be extended by periodic inspection of the anode and replacement if
necessary (refer to “Periodic Maintenance” on page 6 and “Anode” on page 7).
Water Chemistry Levels Affecting Warranty
The Aquamax warranty of this water heater will not cover resultant faults if the water supply has a saturation
index < –1.0 or > 0.4 (refer to “Scaling Water & Saturation Index”on page 9).
The Aquamax warranty of this water heater will not cover resultant faults on components including the
storage cylinder where water stored in the storage cylinder exceeds at any time any of the following levels:
Total dissolved solids
600 mg/Litre
Total hardness
200 mg/Litre
Chloride
250 mg/Litre
Magnesium
10 mg/Litre
pH
9.5 and not less than 6.0
Calcium
20 mg/Litre
Sodium
150 mg/Litre
Iron
1 mg/Litre
Scaling Water & Saturation Index
The saturation index is used as a measure of water‟s corrosive or scaling properties.
In a corrosive water supply, water can attack copper parts and cause them to fail. Where the saturation index
is less than –1.0, the water is very corrosive and the Aquamax warranty does not apply to the water heater.
Where the saturation index exceeds +0.40, the water is very scaling and the Aquamax warranty does not
apply to the water heater.
Scaling water is water that contains levels of calcium carbonate (total hardness in excess of 200 mg/Litre at
any time when the water heater is operating). Scaling water can block and prevent the pressure &
temperature relief valve from operating resulting in damage to the water heater storage cylinder and water
heater components.
An expansion control valve is mandatory in SA & WA and must be fitted in ALL areas with scaling water to
assist in preventing blockage of the pressure and temperature relief valve.
Danger: Failure to install an expansion control valve where scaling water conditions occur may result in
the water heater storage cylinder failing, or under certain circumstances, exploding.
To avoid damage to the storage cylinder and water heater components, Aquamax strongly recommend
scaling water be treated before entering the water heater by fitting appropriate water filters/conditioners etc.
Refer to your Local Water Authority for information on water in your area. A build up of white sediment on hot
water taps or shower roses can be indicative of scaling water. Contact Aquamax if this condition is observed.
Chloride and Ph
Where the chloride level exceeds 250 mg/L the Aquamax warranty does not apply to the water heater. In a
high chloride water supply, the water can corrode stainless steel parts and cause them to fail.
Where the pH is less than 6.0 or greater than 9.5, the Aquamax warranty does not apply to the water heater.
pH is a measure of whether the water is alkaline or acid. In an acidic water supply, the water can attack
stainless steel parts and cause them to fail.
Water with a pH less than 6.0 may be treated to raise the pH. The water supply from a rainwater tank in a
metropolitan area is likely to be corrosive due to the dissolution of atmospheric contaminants.
Spring, Dam, Bore & River Water Supplies
The Aquamax warranty of this water heater will not cover resultant faults on components including the
storage cylinder due to the effects of sludge and/or sediment as a result of connection to a water supply from
silted or treated sources i.e. springs, dams, bores, rivers or towns supplied from a bore.

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Troubleshooting
Check the items below before making a service call. If the water heater is within the warranty period you will
be charged for attending to any condition or fault that is not related to manufacture or failure of a part. For
warranty terms and conditions (refer to “Warranty” on page 29).
Not Enough Hot Water (Or No Hot Water)
Is the water heaters electricity supply switched on?
Have your electrician check to ensure the water heater is switched on and that there is electricity at the
water heater.
Note: Check the electricity supply to which the water heater is connected. If the water heater is
connected to an Off-Peak or time controlled electricity supply, heating hours will be restricted. The
HP325-36-1B model water heater is recommended for connection to a minimum 16 hour per day power
supply.
Is a timer installed?
If a timer has been installed, ensure sufficient time has been allowed to reheat the storage cylinder.
Note: The HP325-36-1B model water heater is recommended for connection to a minimum 16 hour per
day power supply.
Are you using more hot water than you think?
Is one outlet (especially the shower) using more hot water than you think? Very often the amount of hot
water used is not realised, particularly when showering. Carefully review the family‟s hot water usage.
Have your plumber install a flow control valve to each shower outlet to reduce water usage.
Has the heat pump detected a fault?
If the heat pump detects certain fault conditions, the water heater will deactivate heat pump operation
and switch to backup heating mode to ensure a supply of hot water. In backup heating mode the water
in the storage cylinder will be heated by the heating unit and the red LED will provide fault indication by
flashing (refer to “Heat Pump is Not Operating” on page 11 and “Operating Mode Monitor LED
Indication” on page 14).
Pressure temperature relief valve running
Is the PTR valve discharging too much water? Refer to “Pressure Temperature Relief Valve Running”
on page 12.
Water heater size
Do you have the correct size water heater for your requirements? The sizing guide in the sales literature
suggests average sizes that may be needed.
Water Too Hot
During heat pump operation the water in the storage cylinder will be heated to a temperature of 60°C. This is
normal operation.
In booster heating mode or back up heating mode the water in the storage cylinder will be heated to 70°C.
Booster heating mode: The heat pump will operate when the ambient air temperature is between a minimum
of 3°C to 5°C and a maximum of 45°C to 55°C. If the ambient air temperature is outside this temperature
range and heating is required, the water heater will deactivate heat pump operation and switch to booster
heating mode. In booster heating mode the water in the storage cylinder is heated by the booster heating
unit and the green LED will indicate a long flash. This is normal operation (refer to “Operating Mode Monitor
LED Indication” on page 14).
Backup heating mode: If the heat pump detects certain fault conditions, the water heater will deactivate heat
pump operation and switch to backup heating mode to ensure a supply of hot water. In backup heating
mode, the booster heating unit will operate if heating of the water is required, regardless of the ambient air
temperature. The red LED will flash to indicate the fault mode that has occurred (refer to “Heat Pump is Not
Operating” on page 11 and “Operating Mode Monitor LED Indication” on page 14).

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Heat Pump is Not Operating
There must be power available at the water heater and to the heat pump for the heat pump to operate and
for the LEDs to glow or flash (for LED information, refer to “Operating Mode Monitor LED Indication” on page
14).
Time controlled power supply (no power at the water heater)
If the water heater is connected to a time controlled power supply, then during periods of no power
supply at the water heater the LEDs will be off. This is not a fault condition, but a result of no power
being available to energise the LEDs. The green LED will recommence glowing or flashing when power
is available again at the water heater.
Heat pump operating range (no power to the heat pump)
The heat pump‟s operating range is between an ambient air temperature of a minimum of 3°C to 5°C
and a maximum of 45°C to 55°C. The heat pump will not operate when the ambient air temperature is
outside the heat pump‟s operating range. If heating is required, the water heater will commence heating
with the booster heating unit in booster heating mode (long green flash) instead. The water will be
heated to 70°C during these periods.
At the completion of this heating cycle by the booster heating unit (long green flash), the thermostat
controlling the booster heating unit opens circuit cutting power to the heat pump causing the green LED
to go out. This is not a fault condition, but a result of the power being cut to the heat pump by the
thermostat.
The green LED will remain off for an extended period of time until the water temperature in the top of
the water heater drops to below 62°C and the thermostat closes circuit reinstating power to the heat
pump when the red LED will emit a solid glow for three (3) seconds and then extinguish. The green LED
will then recommence to glow or flash.
The green LED will glow (standby mode –water is hot) if the water temperature in the lower part of the
water heater is 50°C or more.
The green LED will flash if the water temperature in the lower part of the water heater is less than 50°C.
If at least 45 minutes has elapsed after power is reinstated to the heat pump, i.e. 45 minutes after the
red LED emitted a solid glow for three (3) seconds and then extinguished, heating of the water by the
heat pump will recommence (3 x green flashes) if the ambient air temperature has moved back to within
the heat pump‟s operating range, or the water heater will switch to the booster heating unit (long green
flash) if the ambient air temperature is outside of the heat pump‟s operating range.
Thermal cut out activated
The refrigeration circuit is protected by a thermal sensor. This will activate a thermal cut out in the event
of thermal surges or excessive heat in the refrigeration system.
If the thermal cut out activated, the red LED will flash a fault mode of a series of single flashes and the
heat pump will not operate. The water heater will switch to backup heating mode using the booster
heating unit to ensure a supply of hot water. In backup heating mode the water will be heated to a
temperature of 70°C.
The thermal cut out will automatically reset when the booster heating unit has completed one heating
cycle and the compressor cools down (refer to “Backup heating mode and series of red flashes” on
page 11).
Heat pump fault condition
If the heat pump has developed fault, the heat pump will not operate and the red LED will flash a fault
mode of a series of one (1) to nine (9) flashes.
If a series of two (2) red flashes occur, the heat pump will not switch to backup heating mode. Phone
Aquamax Service or their nearest Accredited Service Agent to arrange for an inspection.
If a single flash or a series of three (3) to nine (9) red flashes occurs, the water heater will switch to
backup heating mode to ensure a supply of hot water (refer to “Backup heating mode and series of red
flashes” on page 11).
Backup heating mode and series of red flashes
During the backup heating mode by the booster heating unit, caused by either the thermal cut out
activating or a heat pump fault condition, the red LED will emit a series of flashes.
At the completion of a heating cycle by the booster heating unit in the backup heating mode and the
water temperature reaches 70°C, the thermostat controlling the booster heating unit opens circuit cutting
power to the heat pump causing the red LED to go out. The fault mode is recorded to the heat pump
controller‟s memory. The fault condition which led to the red LED flashing may be cleared when the
backup heating cycle has completed.

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Both LEDs will remain off for an extended period of time until the water temperature in the top of the
water heater drops to below 62°C and the thermostat closes circuit reinstating power to the heat pump.
The red LED will recommence to flash the fault mode for thirty (30) seconds and then extinguish. If the
red LED then recommences to flash, the fault condition which led to the red LED flashing may not have
cleared and there may be a problem with the heat pump. Count the number of red flashes and phone
Aquamax Service or their nearest Accredited Service Agent to arrange for an inspection.
At the end of the thirty (30) second period, the green LED will commence to glow or flash.
The green LED will glow (standby mode –water is hot) if the water temperature in the lower part of the
water heater is 50°C or more.
The green LED will flash if the water temperature in the lower part of the water heater is less than 50°C.
Note: If the green LED is glowing, then to check whether there may be problem with the heat pump,
open a hot tap and allow to run for ten (10) to fifteen (15) minutes. This will draw cold water into the
lower part of the water heater and the green LED will commence to flash. Close the hot tap when the
green LED commences to flash.
The heat pump will commence to operate when the green LED is flashing and at least 45 minutes has
elapsed after power is reinstated to the heat pump, i.e. 45 minutes after the red LED flashed the fault
mode for thirty (30) seconds and then extinguished.
If the heat pump stops operating and the red LED recommences to flash, the fault condition which led to
the red LED flashing may not have cleared and there may be a problem with the heat pump. Count the
number of red flashes and phone Aquamax Service or their nearest Accredited Service Agent to arrange
for an inspection.
Note: If the ambient air temperature is outside of the heat pump‟s operating range, the water heater may
switch to the booster heating unit (long green flash) to heat the water in booster heating mode.
The fault mode is cleared from the heat pump controller‟s memory after the water heater successfully
completes a full heat up cycle using the heat pump.
Green LED is off
There may be a fault condition with the heat pump if:
there is power available at the water heater, the green LED is off, and
the water heater has not operated outside of the heat pump‟s operating range – refer to “Heat
pump operating range” on page 11.
Before phoning to arrange a service inspection:
Inspect the isolating switch marked “HOT WATER” or “WATER HEATER” at the switchboard and
the isolating switch (if one is installed) at the water heater and ensure they are turned on
Check the fuse marked “HOT WATER” or “WATER HEATER” at the switchboard
If a timer is installed, check the time settings.
Check the power supply tariff the water heater is connected to confirm power should be available to
the water heater.
Have your electrician check to ensure the water heater is switched on and that there is electricity
present at the water heater.
Refer also to “Thermal cut out activated” on page 11 and to “Heat pump fault condition” on page 11.
If the green LED is off and one of these conditions is not the cause, phone Aquamax Service or their
nearest Accredited Service Agent to arrange for an inspection.
Pressure Temperature Relief Valve Running
Normal Operation
It is normal and desirable for the PTR valve to allow a small quantity of water to escape during the
heating cycle, however there may be a problem if the valve continuously dribbles more than a bucket
full of water in a normal 24 hour cycle. Note: During the first 24 hours after installation the valve may
discharge more than a bucket full of water. This is normal however excess discharge should only occur
during the initial 24 hour heat up period.
Continuous dribble
Try gently raising the easing lever on the relief valve for a few seconds (refer to “Pressure Temperature
Relief Valve” on page 7). This may dislodge a small particle of foreign matter and clear the fault.
Release the lever gently.

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Steady flows for long periods (often at night)
This may indicate the mains water pressure sometimes rises above the designed pressure of the water
heater. Ask your installing plumber to fit a pressure limiting valve.
Warning: Never use reconditioned relief valves and never replace the relief valve with one of a
higher pressure rating.
Heavy flows of hot water until the water heater is cold - then stops until water reheats
The water heater must be switched off at the isolating switch or switchboard. Phone Aquamax Service
or their nearest Accredited Service Agent to arrange for an inspection.
Expansion Control Valve Running
If an expansion control valve is fitted in the cold water supply line to the water heater, it may discharge a
small quantity of water instead of the water heaters pressure temperature relief valve. This has the benefit of
conserving energy as the discharged water is cooler (refer to the “Cold Water Supply Plumbing
Arrangement” diagram on page 20 for expansion control valve location).
Higher Than Expected Electricity Bills
With the installation of your new air sourced heat pump water heater, maximum electrical energy savings can
be achieved. Check the following points if your electricity bill is higher than expected:
Is the water heater operating in backup heating mode with the red LED flashing?
If there is a fault condition with the heat pump system, the water heater will default to backup heating
mode to ensure a supply of hot water. Check to see if the red LED is flashing as this will indicate there
may be a fault with the system (refer to “Heat Pump is not Operating” on page 11).
Is the relief valve running excessively?
Refer to “Pressure Temperature Relief Valve Running” on page 12.
Is one outlet (especially the shower) using more hot water than you think?
Refer to “Not Enough Hot Water” on page 10.
Is there a leaking hot water pipe, dripping hot water tap, etc?
Even a small leak will waste a surprising quantity of hot water and energy. Replace faulty tap washers
and have your plumber rectify any leaks.
Has there been an increase in hot water usage?
An increase in hot water usage will result in an increase in heat pump operation.
Has your water heating tariff rate been increased by your electricity retailer since your previous bill?
Check your previous bill and compare electricity rates and charges.
Is the heat pump water heater on the same tariff as the water heater replaced?
The impact on an electricity account will depend upon the tariff arrangement of the water heater
replaced and where you live. Contact your energy provider for more information on tariff arrangements
and cost comparisons.
Has the ambient air temperature been very cold or very hot?
Prolonged periods of use when the ambient air temperature is outside of the heat pumps operating
range will increase the amount of boosting and increase running costs.
If you have checked all the previous troubleshooting points and still believe you need assistance,
phone Aquamax Service or their nearest Accredited Service Agent.

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Operating Mode Monitor LED Indication
An operating mode monitor is located on the front of the heat pump module and houses a green and a red
LED.
The green LED, marked “HEAT PUMP or BOOST”, indicates the current operating mode of the heat pump
water heater and the red LED, marked “RESET or SERVICE”, indicates a fault mode.
The green LED will emit either a constant glow or a series of flashes, with a 2 second interval between each
series. A series of long green flashes may also be emitted.
The red LED will emit a series of flashes, with a 2 second interval between each series, only if there is a
particular fault condition with the system.
Diagnostic Features of the Heat Pump Controller
Flashes
Operational Mode
solid green
(remains on)
Standby mode –water is hot
1 x green
Call for heating received –system checks performed
Note: unit may wait and continue flashing until compressor has cooled from its last operation
2 x green
Circulator commences circulation
3 x green
Heat pump operation –compressor and fan running
long green
Heating unit on –ambient air temperature below 3°C to 5°C or above 45°C to 55°C
no green
(remains off)
No power at the water heater or to the heat pump or a possible fault condition
Refer to notes below before calling for service
Flashes
Fault Mode
1 x red
Heating unit on compressor over temperature (possible circulator fault)
2 x red
Heating unit off compressor fault condition
3 x red
Heating unit on compressor cooling fault condition
4 x red
Heating unit on tank thermistor fault condition
5 x red
Heating unit on evaporator thermistor fault condition
6 x red
Heating unit on compressor thermistor fault condition
9 x red
Heating unit on compressor fault condition
Heating unit is the electric booster heating unit.
Notes:
Power must be available at the water heater and to the heat pump for the LEDs to glow or flash.
There are no 7 or 8 x red flash fault mode codes.
When power is turned on or reconnected to the water heater, the red LED will emit a solid glow for
three (3) seconds and then extinguish. This is normal operation and does not indicate a fault. The LED
display will then return to the current operational status.
If there is power to the water heater and the green LED is off or the red LED is flashing, this indicates
there may be a fault condition with the water heater. The red LED may emit up to nine flashes in each
series of flashes (refer to “Possible fault condition” on page 15).
Time controlled power supply (power must be available at the water heater)
If the water heater is connected to a time controlled power supply, then during periods of no power
supply at the water heater the LEDs will be off. This is not a fault condition, but a result of no power
being available to energise the LEDs. The green LED will recommence glowing or flashing when power
is available again at the water heater.

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Possible fault condition
There may be a fault condition with the water heater if either:
there is power available at the water heater and the green LED is off, and
the water heater has not operated outside the heat pump‟s operating range.
Before phoning to arrange a service inspection due to the green LED being off, refer to “Heat Pump
Is Not Operating” on page 11 in the “Troubleshooting” section of this Owner‟s Guide.
or
the red LED is flashing - the red LED may emit up to nine flashes in each series of flashes.
The fault condition which led to the red LED flashing may be cleared after the backup heating cycle
by the booster heating unit has been completed. When heating is next required the red LED will
recommence to flash the fault code for thirty (30) seconds and then extinguish. If the red LED then
recommences to flash or recommences to flash after the heat pump next operates, a service call
may be required.
Before phoning to arrange a service inspection due to the red LED flashing, refer to “Heat Pump Is
Not Operating” on page 11 in the “Troubleshooting” section of this Owner‟s Guide.

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INSTALLATION
Installation Overview
This water heater must be installed by a qualified person in accordance with the installation instructions. The
installation must comply with the requirements of AS/NZS 3500.4, AS/NZS 3000 and all local codes and
regulatory authority requirements.
This heat pump water heater is comprised of the following components:
Storage cylinder.
Heat pump module.
For transport and handling (weight) purposes both items are shipped separately and designed to be
assembled at the installation site. The water heater must not be operated until both components are
assembled. Refer to “Heat Pump and Storage Cylinder Assembly” on page 18.
Take care when handling the heat pump module. The jacket of the heat pump module needs to be handled
gently so as not to cause damage.
Care must be taken during transportation and handling. Do not lay the heat pump module down and
do not tilt the heat pump module or the heat pump and storage tank assembly more than 30° from the
vertical. This will displace the compressor lubricating oil. If the heat pump module or heat pump and storage
cylinder assembly has been tilted more than 30° from the vertical during handling, it will need one hour to
drain back before the power to the water heater can be switched on, otherwise damage to the compressor
may result.
All packaging materials must be removed from the water heater prior to its installation. This includes the
removal of the cardboard base of the carton from the underside of the water heater.
This water heater is not suitable for pool heating.
Typical Installation –Outdoor Location

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Victorian Installers
Notice to Victorian Installers from the Victorian Plumbing Industry Commission if this water heater is installed
in a new Class 1 dwelling in the State of Victoria. The system model number is to be recorded on the
Certificate of Compliance. It is also a requirement to provide the householder with permanent documentation
recording the system model number exactly as it is shown in the „List of systems capable of complying with
the regulations‟ published by Sustainability Victoria (see www.sustainability.vic.gov.au). This documentation
may be in the form of an indelible label adhered to the storage tank, or other suitable form placed in an
accessible location, such as the meter box, for later inspection.
Hot Water Redundancy
If this water heater is to be used where an uninterrupted hot water supply is necessary for the application or
business, then there should be redundancy within the hot water system design. This should ensure the
continuity of hot water supply in the event that this water heater was to become inoperable for any reason.
We recommend you provide advice to the system owner about their needs and building backup redundancy
into the hot water supply system.
Water Supplies
Mains Water Supply
Where the mains water supply pressure exceeds that shown in the table below, an approved pressure
limiting valve is required and should be fitted after the stop cock and before the non return valve as shown in
the “Cold Water Supply Plumbing Arrangement” diagram on page 20.
Model
HP325-36-1B
Pressure temperature relief valve setting
1000 kPa
Expansion control valve (ECV) setting *
850 kPa
Minimum mains supply pressure
200 kPa
Maximum mains supply pressure
With ECV
680 kPa
Without ECV
800 kPa
* Expansion control valve not supplied with water heater.
A minimum water supply pressure of 200 kPa is required to enable the heat pump circulator and heat pump
system to operate effectively.
Tank Water Supply
If the water heater is supplied with water from a tank supply and a minimum water supply pressure of
200 kPa at the water heater cannot be achieved, then a pressure pump system must be installed to allow the
heat pump circulator to operate and avoid air locks in the circuit. Care must be taken to avoid air locks. The
cold water line from the supply tank should be adequately sized and fitted with a full flow gate valve or ball
valve.
Water Supply Chemistry
Bad water can have a detrimental effect on water heater operation, components and life expectancy and
may affect warranty. Refer to “Water Chemistry” on page 8 for more information. Also refer to “Spring, Dam,
Bore & River Water Supplies” on page 9.

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INSTALLATION –COMPONENTS
This section details the installation of the storage cylinder and heat pump module. To install the water heater
plumbing refer to the “Installation – Plumbing & Plumbing Connections” section on page 20.
Water Heater Location
This water heater is suitable for outdoor installation only. The water heater should be installed close to the
most frequently used outlet and its position chosen with noise, safety and service in mind. Make sure people
(particularly children) will not accidentally touch the air inlet louvres and outlet grille and that louvres and
grille are clear of obstructions and shrubbery.
It is advisable to install the water heater away from bedroom or living room windows as the system controls
can generate a level of noise whilst they are operating. Also consider the location in relation to neighbours‟
bedrooms and living room windows.
Sufficient and safe space for ease of service and access to system controls, heating unit, thermostat,
sacrificial anode and relief valves should be considered when locating the water heater. The water heater
must be installed at ground level, stand upright in a vertical position and must be accessible without the use
of a ladder or scaffold. The base of the water heater is made of corrosion resistant material, and it may be
placed directly in contact with the supporting surface. It is not necessary to allow for free air circulation under
the base of the water heater.
You must be able to read the information on the rating plate. If possible, leave headroom of one water heater
height so the anode can be inspected and / or replaced. If adequate room is unavailable, the water heater
must be disconnected, drained and removed to enable servicing.
The heat pump storage cylinder and module must be installed on a level slab or solid base of a minimum
900 mm wide x 650 mm deep. The heat pump module must be fully supported by the level slab or solid
base. Note: The water heater should not be placed in direct contact with a concrete surface that is less than
two months old and not fully cured, as this may attack the metal coating of the water heater base. A moisture
barrier should be used between the two surfaces in this instance.
The water heater must be installed with a clearance of at least 100 mm from a wall. A clearance of at least
300 mm is required perpendicular from both the front air inlet louvres and the outlet grille to any wall or
obstruction (refer to the dimensional diagram on page 28).
The water heater must not be installed in an area with a corrosive atmosphere where chemicals are stored or
where aerosol propellants are released. Remember the air may be safe to breathe, but the chemicals may
attack the materials used in the heat pump system.
Do not install this water heater in a roof space as a mains pressure storage water heater.
Note: Damage to the storage cylinder caused by incorrect installation is not covered by warranty.
Heat Pump Module & Storage Cylinder Assembly
Overview
The heat pump water heater is made
of two main components, the storage
cylinder and the heat pump module.
For transport and handling (weight)
purposes both items are shipped
separately and designed to be
assembled at the installation site. The
water heater must not be operated
until both components are assembled.
Warning: The heat pump module
is designed to be installed with a
purpose built water heater storage
cylinder and may not be used for any
other purpose.

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Heat Pump Module
The heat pump module is shipped in a box containing two hand holes to facilitate easy handling and lifting.
The heat pump module is to be mounted against the side of the storage tank and must be fully supported by
the level slab or solid base.
Warning: The heat pump module weighs approximately 37 kg. Use the hand holes provided in the sides
of the packaging. Good lifting practice should be followed.
There are two flexible hoses provided inside the heat pump module. The flexible hoses are to be withdrawn
from the module and fixed to the two water fittings on the heat pump storage cylinder during the assembly
procedure.
There are two connection points located on the underside of the control box in the heat pump module to
which the power cable and tank sensor cable from the heat pump storage cylinder are connected during the
assembly procedure.
Storage Cylinder
The heat pump storage cylinder and module must be installed on a level slab or solid base of a minimum
900 mm wide x 650 mm deep. The storage cylinder is designed to receive the heat pump module.
There are two water fittings located at the side of the storage cylinder to which flexible hoses from the heat
pump module are connected, during the assembly procedure.
A power cable and a tank sensor cable are provided behind the lower cover of the storage cylinder. These
are to be withdrawn from behind the front cover and connected to the control box in the heat pump module
during the assembly procedure.
Assembly Procedure
Warning: The heat pump module and storage cylinder must be assembled, plumbed and filled with
water prior to power being connected and switched on.
Refer to the installation instructions supplied with the heat pump module for the heat pump module assembly
procedure.