Rheem 310 Series Technical Document

This water heater must be installed and serviced by an authorised person.
Please leave this guide with the householder.
Owner’s Guide
and
Installation Instructions
Air Sourced 310 Heat Pump
Water Heater

PATENTS
This water heater may be protected by one or more patents or registered designs in the name of
Rheem Australia Pty Ltd.
TRADE MARKS
®Registered trademark of Rheem Australia Pty Ltd.
™ Trademark of 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.
Notice to Victorian Customers from the
Victorian Plumbing Industry Commission.
This water heater must be installed by a licensed person as required by the
Victorian Building Act 1993.
Only a licensed person will give you a Compliance Certificate, showing that the work complies with all the
relevant Standards. Only a licensed person will have insurance protecting their workmanship for 6 years.
Make sure you use a licensed person to install this water heater and ask for your Compliance Certificate.

3
CONTENTS
HOUSEHOLDER –We recommend you read pages 4 to 13.
The other pages are intended for the installer but may be of interest.
About Your Water Heater............................................................................................................ 4
Regular Care................................................................................................................................ 8
Water Supplies............................................................................................................................. 9
Save A Service Call................................................................................................................... 11
Installation.................................................................................................................................. 14
Heat Pump And Tank Assembly.............................................................................................. 21
Connections –Plumbing.......................................................................................................... 28
Connections –Electrical........................................................................................................... 30
Multiple Installations................................................................................................................. 32
Commissioning.......................................................................................................................... 35
Draining The Water Heater....................................................................................................... 36
Warranty..................................................................................................................................... 39

4
ABOUT YOUR WATER HEATER
MODEL TYPE
Your Rheem®air sourced heat pump water heater is designed for outdoor installation only. The model you
have chosen is a 551 series model. The 551 310 model heat pump water heater is recommended for
connection to a minimum 16 hour per day power supply.
A Rheem 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.
The Rheem air sourced heat pump water heater has a Rheemglas®vitreous enamel lined steel cylinder. The
water heater‟s evaporator absorbs heat from the surrounding air and transfers this heat into the water.
When hot water is drawn off and cold water enters the tank, the thermostat activates a fan, a compressor
and a circulator. The fan draws outside air in through the air inlet louvres at the top of the water heater and
the pump circulates water from the bottom of the storage tank through a heat exchanger. Heat is absorbed
from the air by an evaporator and transferred into the water through the heat exchanger. The resulting cold
air is then discharged through the air outlet louvres back to atmosphere and the heated water is circulated
back into the top of the storage tank. This process continues while ever heating is required until the water in
the storage tank 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 5°C or higher.
The booster heating unit will operate when the ambient air temperature
falls below 5°C, if heating is required. The efficiency of the water heater
increases as the surrounding ambient air temperature increases.
Automatic safety controls are fitted to the water heater to provide safe and
efficient operation.
ELECTRIC BOOSTING
Ice may begin to form on the evaporator reducing the heat pump efficiency,
when the ambient air temperature falls below 7°C and the heat pump has
been operating for an extended period. At ambient air temperatures below
5°C, the water heater deactivates the heat pump operation and switches to
the booster heating unit. During this period the evaporator will defrost if
necessary.
The boost capacity in this mode is 220 litres. The water inside the tank will
be heated to a temperature of 60°C by the electric booster heating unit if
heating is required. The temperature setting of the sensor controlling the
booster heating unit is not adjustable and is set at 60°C.
MAINS PRESSURE
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 on page 15, 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.

ABOUT YOUR WATER HEATER
5
HOW HOT SHOULD THE WATER BE?
The system controls (compressor, evaporator and fan) will
operate until a water temperature of approximately 60 C is
reached. If the ambient air temperature is outside of the heat
pump‟s operating range, the water temperature is boosted
automatically to 60°C by the electric booster heating unit, if
heating is required.
To meet the requirements of the National Plumbing Standard
the temperature of the stored water must not be below 60 C.
HOTTER WATER INCREASES THE RISK OF SCALD INJURY
This water heater can deliver water at temperatures which can
cause scalding. 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.
We recommend and it may also be required by regulations that
an approved temperature limiting device be fitted into the hot
water pipe work to the bathroom and ensuite when this water
heater is installed. This will keep the water temperature below
50 C at the bathroom and ensuite. The risk of scald injury will
be reduced and still allow hotter water to the kitchen and
laundry.
TEMPERATURE ADJUSTMENT
The thermostats controlling the heat pump and the booster heating unit are factory set and not adjustable.
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.
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 an authorised or qualified person.
Do not use aerosols, stain removers and household chemicals near the water heater whilst it is
working. Gases from some aerosol sprays, stain removers and household chemicals are corrosive to the
materials used in the heat pump system.
Do not store swimming pool chemicals, household cleaners, etc., near the water heater.
Ensure the air inlet and outlet louvres and air flow are not obstructed in any way at any time.
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 an
authorised or qualified person.
If the electrical supply conduit to the water heater is damaged, it must be replaced by an authorised person
in order to avoid a hazard. Phone your nearest Rheem Service Department or Accredited Service Agent to
arrange for an inspection.
The warranty can become void if relief valves or other safety devices are tampered with or if the
installation is not in accordance with these instructions.
typical maximum temperature
from heat pump operation;
booster temperature setting;
minimum recommended stored
water temperature
maximum recommended supply
temperature to bathrooms and
ensuites

ABOUT YOUR WATER HEATER
6
TO TURN OFF THE WATER HEATER
If you plan to be away from home for only a few nights, we suggest you leave the water heater switched on.
If it is necessary to turn off the water heater:
Switch off the electrical supply at the isolating switch to the water heater.
Close the cold water isolation valve at the inlet to the water heater.
TO TURN ON THE WATER HEATER
Open the cold water isolation valve fully on the cold water line to the water heater.
Switch on the electrical supply at the isolating switch to the water heater.
The heat pump may take up to 30 seconds to commence operating when the power supply is switched on.
The heat pump will only operate when the water in the storage tank requires heating, the heat pump
compressor is cool and power is available at the water heater. If the ambient air temperature is below the
minimum operating temperature of 5°C and the system calls for heating, the booster heating unit will operate
instead.
When the heat pump is operating, the system may switch to the booster heating unit if it detects that the
ambient air temperature is below the minimum operating temperature of 5°C. It may also switch back to heat
pump operation from the booster heating unit if it detects the ambient air temperature has moved back to
within the heat pump‟s operating temperature range.
Note: The heat pump may not turn on after having just completed a heating cycle and more hot water is
drawn from the water heater. 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 may take up to
20 minutes from the last heating cycle.
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 551 310 model heat pump water heater is recommended for connection to a minimum 16 hour per
day power supply.
GOING ON HOLIDAYS
If you plan to be away from home for a few nights, we suggest you leave the water heater switched on. If you
plan to be away for a longer period, conserve energy by switching off the isolating switch to the water heater
(refer to “To Turn Off The Water Heater” on page 6).
HOW DO I KNOW IF THE WATER HEATER IS INSTALLED CORRECTLY?
Installation requirements are shown on page 19. The water heater must be installed by an authorised person
and the installation must comply with Standards AS/NZS 3500.4, AS/NZS 3000 and all local codes and
regulatory authority requirements. In New Zealand, the installation must conform with Clause G12 of the New
Zealand Building Code.
DOES THE WATER CHEMISTRY AFFECT THE WATER HEATER?
The water heater is suitable for most public water supplies, however some water chemistries may have
detrimental effects on the water heater and fittings. Refer to “Water Supplies” on page 9. If you are not
sure, have your water chemistry checked against the conditions described on pages 9 to 10.
HOW LONG WILL THE WATER HEATER LAST?
There are a number of factors that will affect the length of service the water heater will provide. These
include the water chemistry, the water pressure, temperature (inlet and outlet) and the water usage pattern.
However, your water heater is supported by a comprehensive warranty (refer to page 40).

ABOUT YOUR WATER HEATER
7
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 your nearest Rheem Service Department or Accredited
Service Agent to arrange for an inspection.

8
REGULAR CARE
TEMPERATURE PRESSURE RELIEF VALVE
This valve is near the top of the water heater and is essential for its safe operation. It is possible for the 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 valve and its drain line may
indicate a problem with the water heater (refer to “Temperature
Pressure Relief Valve Running” on page 13).
Warning: Never block the outlet of this valve or its drain line for
any reason.
Operate the easing lever on the temperature pressure relief valve
once every six months. It is very important you raise and lower
the lever gently.
DANGER: Failure to do this may result in the water heater
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 should be checked by your nearest
Rheem Service Department or Accredited Service Agent.
The temperature pressure relief 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 Supplies” on page 9).
EXPANSION CONTROL VALVE
In many areas, including South Australia, Western Australia and
scaling water areas, an expansion control valve is fitted to the cold
water line to the water heater. The expansion control valve may
discharge a small quantity of water from its drain line during the
heating period instead of the temperature pressure relief 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.
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.
water
heater
drain
line
lift until water
flows from the
drain line –
lower gently

9
WATER SUPPLIES
This water heater must be installed in accordance with this advice to be covered by the 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 water heater warranty to apply.
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 warranty to apply.
ANODE
The vitreous enamel lined cylinder of the water heater is only covered by warranty when the total dissolved
solids (TDS) content in the water is less than 2500 mg/L and when the correct colour coded anode is
installed. The use of an incorrect colour coded anode will void the warranty and may shorten the life of the
storage tank.
The correct colour coded anode is as shown in the following table:
Total Dissolved Solids
Anode colour code
0 –40 mg/L
Green
40 –150 mg/L
Green or Black
150 –400 mg/L
Black
400 –600 mg/L
Black or Blue
600 –2500 mg/L
Blue
2500 mg/L +
Blue (no cylinder warranty)
The changing of anodes must be carried out by a plumber or authorised service person.
Note: 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.
ANODE INSPECTION
The anode installed in the water heater will slowly dissipate whilst protecting the cylinder. The life of the
cylinder may be extended by arranging for an authorised person to inspect the anode and replace if required.
The suggested maximum time after installation when the anode should be inspected for this heat pump
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 inspected
3 years earlier than shown.

WATER SUPPLIES
10
CAUTION
If the water supply has a TDS greater than 150 mg/L and a green anode has not been changed to a black
anode, or if the TDS is 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. In areas where this is likely to occur, the installer should instruct the
householder on how to dissipate the gas safely.
If, under these conditions, the water heater has not been used for two or more weeks the following procedure
should be carried out before using any electrical appliances (automatic washing machines and dishwashers)
which are connected to the hot water supply.
The hydrogen, which is highly flammable, should be vented safely by opening a hot tap and allowing the
water to flow. There should be no smoking or naked flame near the tap whilst it is turned on. Any hydrogen
gas will be dissipated. This is indicated by an unusual spurting of the water from the tap. Once the water runs
freely, any hydrogen in the system will have been released.
SATURATION INDEX
The saturation index (SI) is used as a measure of the water‟s corrosive or scaling properties.
Where the saturation index is less than –1.0, the water is very corrosive and warranty does not apply to the
water heater. In a corrosive water supply, the water can attack copper parts and cause them to fail.
Where the saturation index exceeds +0.40, the water is very scaling and warranty does not apply to the
water heater.
Water which is scaling may be treated with a water softening device to reduce the saturation index of the
water.
CHLORIDE AND PH
Where the chloride level exceeds 250 mg/L 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 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.
SUMMARY OF WATER CHEMISTRY ADVICE AFFECTING WARRANTY
The warranty of this water heater does not apply on the components listed below if the water heater is
connected at any time to a water supply with water chemistry of:
Water Chemistry
Component
Total Dissolved Solids (TDS) > 2500 mg/L
water heater cylinder
Total Dissolved Solids (TDS) not suitable for anode type
water heater cylinder
Saturation Index (SI) < -1.0
water heater
Saturation Index (SI) > +0.4
water heater
Chloride > 250 mg/L
water heater
pH < 6.0
water heater

11
SAVE A SERVICE CALL
Check the items below before making a service call. You will be charged for attending to any condition or
fault that is not related to manufacture or failure of a part.
NOT ENOUGH HOT WATER (OR NO HOT WATER)
Is the electricity switched on?
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.
Is a timer installed?
If a timer has been installed, ensure sufficient time has been allowed to reheat the storage tank.
Are you using more hot water than you think?
Is one outlet (especially the shower) using more hot water than
you think?
Very often it is not realised the amount of hot water used,
particularly when showering. Carefully review the family‟s hot
water usage. As you have installed an energy saving appliance,
energy saving should also be practised in the home.
Adjust your water usage pattern to take advantage of maximum
energy gains. Have your plumber install a flow control valve to
each shower outlet to reduce water usage.
Heat pump fault
Has the heat pump developed a fault?
The heat pump will not operate and the water heater will switch to backup heating mode. The boost
capacity of the heating unit in backup heating mode is 110 litres.
Refer to “Heat Pump Is Not Operating” on page 12.
Temperature pressure relief valve running
Is the relief valve discharging too much water?
Refer to “Temperature Pressure Relief Valve Running” on page 13.
Water heater size
Do you have the correct size water heater for your requirements?
The sizing guide in the sales literature and on the Rheem website (www.rheem.com.au) suggests
average sizes that may be needed.
WATER NOT HOT ENOUGH
You may find that due to heavy hot water usage the water temperature may be lower than normally
expected, due to insufficient heating time being allowed. You will need to carefully plan your use of the hot
water on such occasions.
WATER TOO HOT
The water heater during heat pump operation and booster heating mode will heat the water to a temperature
of 60°C. If a heat pump component has developed a fault condition, the heat pump will not operate and the
water heater will switch to backup heating mode to ensure a supply of hot water.
In backup heating mode, the booster heating unit and its controlling thermostat will operate if heating of the
water is required, regardless of the ambient air temperature. The water heater, during backup heating mode
will heat the water to a temperature of 70°C. The boost capacity of the heating unit in backup heating mode
is 110 litres.
Phone your nearest Rheem Service Department or Accredited Service Agent to arrange for an inspection.

SAVE A SERVICE CALL
12
HEAT PUMP IS NOT OPERATING
Time controlled power supply
If the water heater is connected to a time controlled power supply, then during periods of no power
supply at the water heater the heat pump and booster heating unit will not operate.
This is not a fault condition, but a result of no power being available to operate the water heater.
Heat pump operating range
The heat pump will not operate for extended periods when the ambient air temperature is outside the
heat pump‟s operating range. The heat pump will operate when the ambient air temperature is 5°C or
higher. The booster heating unit will operate when the ambient air temperature falls below 5°C, if heating
is required.
The boost capacity of the booster heating unit in booster heating mode is 220 litres and the water will be
heated to 60°C during these periods.
Heating of the water by the heat pump will occur when the ambient air temperature returns to within the
heat pump‟s operating range.
Thermal cut out activated
Has the thermal cut out for the heat pump compressor 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 has activated, the heat pump will not operate. The water heater will switch to
booster heating mode to ensure a supply of hot water. If heating of the water is required, the booster
heating unit will operate regardless of the ambient air temperature. In booster heating mode, the boost
capacity of the heating unit is 220 litres and the water will be heated to 60°C.
The thermal cut out will automatically reset itself when the compressor cools down.
To check whether there may be a problem, open a hot tap and allow to run for ten to fifteen minutes.
The heat pump, if working properly, will activate and continue operating to heat the water. Close the hot
tap when the heat pump begins to operate.
However, if the heat pump deactivates within five minutes, there may be a problem. Phone your nearest
Rheem Service Department or Accredited Service Agent to arrange for an inspection.
Heat pump fault
Has the heat pump developed a fault?
If the heat pump has developed a fault condition, the heat pump will not operate and the water heater
will switch to backup heating mode to ensure a supply of hot water.
In backup heating mode, the booster heating unit and its controlling thermostat will operate if heating of
the water is required, regardless of the ambient air temperature. The water heater, during backup
heating mode will heat the water to a temperature of 70°C. The boost capacity of the heating unit in
backup heating mode is 110 litres.
Phone your nearest Rheem Service Department or Accredited Service Agent to arrange for an
inspection.
EXPANSION CONTROL VALVE RUNNING
If an expansion control valve is fitted in the cold water line to the water heater (refer to page 28)it may
discharge a small quantity of water instead of the temperature pressure relief valve on the water heater. The
benefit is that energy is conserved as the discharged water is cooler.

SAVE A SERVICE CALL
13
TEMPERATURE PRESSURE RELIEF VALVE RUNNING
Normal Operation
It is normal and desirable this valve allows a small quantity of water to
escape during the heating cycle. However, if it discharges more than a
bucket full of water in 24 hours, there may be another problem.
Continuous dribble
Try gently raising the easing lever on the relief valve for a few seconds
(refer to “Temperature Pressure Relief Valve” on page 8). This may
dislodge a small particle of foreign matter and clear the fault. Release
the lever gently.
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 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 your nearest
Rheem Service Department or Accredited Service Agent to arrange for an inspection.
HIGHER THAN EXPECTED ELECTRICITY BILLS
With the installation of your new air sourced heat pump water heater, maximum electrical energy savings can
be achieved. Should you at any time, feel your electricity account is higher than expected, we suggest you
check the following points:
Is the water heater operating in backup heating mode?
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. If the water is being heated to a temperature of 70°C, this will
indicate there may be a fault with the system.
Refer to “Heat Pump Is Not Operating” on page 12.
Is the relief valve running excessively?
Refer to “Temperature Pressure Relief Valve Running” on page 13.
Is one outlet (especially the shower) using more hot water than you
think?
Refer to “Not Enough Hot Water” on page 11.
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 leaking pipe work.
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 account?
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.
Prolonged periods of use when the ambient air temperature is outside of the heat pump‟s operating
range will increase the amount of boosting and increase running costs.
IF YOU HAVE CHECKED ALL THE FOREGOING AND STILL BELIEVE YOU NEED ASSISTANCE, CALL
YOUR NEAREST RHEEM SERVICE DEPARTMENT OR ACCREDITED SERVICE AGENT.

14
INSTALLATION
THIS WATER HEATER IS FOR OUTDOOR INSTALLATON ONLY.
THIS WATER HEATER IS NOT SUITABLE FOR POOL HEATING.
The installation must comply with the requirements of AS/NZS 3500.4, AS/NZS 3000 and all local codes and
regulatory authority requirements. In New Zealand, the installation must conform with Clause G12 of the New
Zealand Building Code.
The 551 310 model heat pump water heater is recommended for connection to a minimum 16 hour per day
power supply.
A Rheem 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 the installation
location. Contact the energy provider for more information on tariff arrangements and cost comparisons.
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.
STORAGE TANK AND HEAT PUMP MODULE
The heat pump water heater is made of two main components, the storage tank 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. Refer to “Heat Pump and Tank Assembly” on page 21.
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.
Do not tilt the heat pump module or the heat pump and storage tank assembly more than 45° from
the vertical. This will unsettle the refrigerant gas and compressor lubricating oil. If the heat pump module or
heat pump and storage tank assembly has been tilted more than 45° from the vertical during handling, it will
need one hour to settle before the power to the water heater can be switched on, otherwise damage to the
compressor may result.
The heat pump module and storage tank can be assembled off site if required and then transported to the
installation site. Care must be taken during transportation and handling as the assembly will be top heavy.
WATER HEATER LOCATION
The 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 and outlet louvres and that they 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.
Consider the location in relation to neighbours‟ bedrooms
and living room windows.
Clearance must be allowed for servicing of the water
heater. The water heater must be accessible without the
use of a ladder or scaffold. Make sure the temperature
pressure relief valve lever is accessible and the top and
front cover, air inlet and outlet louvres, system controls
and thermostat can be removed for service.
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 or replaced.
Remember you may have to remove the entire water
heater later for servicing.

INSTALLATION
15
It is recommended the heat pump water heater be installed at ground or floor level and must stand vertically
upright, supported by a level slab or solid base. 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.
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 air inlet and outlet louvres to any wall or obstruction. Refer to
the dimensions diagram on page 20.
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.
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 as shown in the installation diagram (refer to diagram on
page 28).
Model
310
Relief valve setting
1000 kPa
Expansion control valve setting *
850 kPa
Max. mains supply pressure
With expansion control valve
680 kPa
Without expansion control valve
800 kPa
Min. mains supply pressure
200 kPa
* Expansion control valve not supplied with the water heater.
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.
PURGING AIR FROM THE SYSTEM
The water heater system must be purged of air prior to operation, using the air bleed valve supplied on the
heat pump module. Failure to bleed the air out of the pipe work within the heat pump module will result in
non-operation of the circulator and failure of the heat pump to operate due to overheating.

INSTALLATION
16
HOT WATER DELIVERY
This water heater can deliver water at temperatures which can cause scalding.
It is necessary and we recommend that a temperature limiting device be fitted between the water heater and
the hot water outlets in any ablution area such as a bathroom or ensuite, to reduce the risk of scalding. The
installing plumber may have a legal obligation to ensure the installation of this water heater meets the
delivery water temperature requirements of AS/NZS 3500.4 so that scalding water temperatures are not
delivered to a bathroom, ensuite or other ablution area.
The temperature limiting device used with a solar water heater should have a specified minimum
temperature differential, i.e. between the hot water inlet and the tempered water outlet, of no greater than
15°C.
Where a temperature limiting device is installed adjacent to the water heater, the cold water line to the
temperature limiting device can be branched off the cold water line either before or after the isolation valve,
pressure limiting valve and non return valve to the water heater. If an expansion control valve is required, it
must always be installed after the non return valve and be the last valve prior to the water heater.
If a pressure limiting valve is installed on the cold water line to the water heater and the cold water line to a
temperature limiting device branches off before this valve or from another cold water line in the premises,
then a pressure limiting valve of an equal pressure setting may be required prior to the temperature limiting
device.
LEGEND
Two Temperature Zones Using a Temperature Limiting Device

INSTALLATION
17
CIRCULATED HOT WATER FLOW AND RETURN SYSTEM
A 551 310 model heat pump water heater should not be installed as part of a circulated hot water flow and
return system in a building.
If a circulated flow and return system is required, it is necessary to bypass the heat pump water heater and
install a secondary water heater connected to the hot water flow and return line and supplied from the heat
pump water heater. The secondary water heater must be a storage water heater able to provide a hot water
outlet temperature of at least 60 C. Note: The thermostat must always be set to at least 60 C. Refer to the
diagram on page 17.
Temperature Limiting Device
A temperature limiting device cannot be installed in circulated hot water flow and return pipe work. The
tempered water from a temperature limiting device cannot be circulated. Where a circulated hot water flow
and return system is required in a building, a temperature limiting device can only be installed on a dead leg,
branching off the circulated hot water flow and return pipe.
If circulated tempered water were to be returned back to the water heater, depending on the location of the
return line connection on the water supply line to the water heater, then either:
water will be supplied to the cold water inlet of the temperature limiting device at a temperature
exceeding the maximum recommended water supply temperature, or
when the hot taps are closed no water will be supplied to the cold water inlet of the temperature limiting
device whilst hot water will continue to be supplied to the hot water inlet of the temperature limiting
device.
These conditions may result in either water at a temperature exceeding the requirements of AS/NZS 3500.4
being delivered to the hot water outlets in the ablution areas, or the device closing completely and not
delivering water at all, or the device failing. Under either condition, the operation and performance of the
device cannot be guaranteed.
LEGEND
Circulated Hot Water Flow and Return System –Heat Pump Water Heater

INSTALLATION
18
REDUCING HEAT LOSSES
The cold water line to and the hot water line from the water heater must be insulated in accordance with the
requirements of AS/NZS 3500.4. The insulation must be weatherproof and UV resistant if exposed.
ANODE TYPES
The vitreous enamel lined cylinder of the water heater is only covered by warranty when the total dissolved
solids (TDS) content in the water is less than 2500 mg/L and when the correct colour coded anode is
installed. The use of an incorrect colour coded anode will void the warranty and may shorten the life of the
storage tank. The black anode is typically fitted as standard (refer to “Anode” on page 9).
If an incorrect anode is used, there is also 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. In areas where this is
likely to occur, the installer should instruct the householder on how to dissipate the gas safely (refer to
“Caution” on page 10).
SADDLING - PIPE WORK
To prevent damage to the cylinder when attaching pipe clips or saddles to the water heater jacket, we
recommend the use of self-drilling screws with a maximum length of 13 mm. Should pre drilling be required,
extreme caution must be observed when penetrating the jacket of the water heater.
Note: Damage to the cylinder as a result of saddling to the jacket will void the warranty.

INSTALLATION
19
TYPICAL INSTALLATON –OUTDOOR LOCATION
TYPICAL INSTALLATION
HEAT PUMP WATER HEATER

INSTALLATION
20
DIMENSIONS AND TECHNICAL DATA
HEAT PUMP DIMENSIONS
System number
551 310
Part numbers
Model Number 1.8 kW
551 310 04
Tank only 1.8 kW
T551 310 04
2.4 kW
551 310 05
Tank only 2.4 kW
T551 310 05
3.6 kW
551 310 07
Tank only 3.6 kW
T551 310 07
Heat pump module
180532
Maximum rated power input
3600 watts
Storage capacity
310 litres
Rated heat pump power input
1300 watts
Boost capacity
220 litres
Booster element rating
1800, 2400 or 3600 watts
Mass empty - total
135 kg
Refrigerant type
R134a
Storage tank
87 kg
Refrigerant circuit pressure
3000 kPa
Heat pump module
48 kg
Mass full - total
445 kg
Specifications are subject to change with ongoing product improvements.