Rheem 310 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 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.

3
CONTENTS
HOUSEHOLDER –We recommend you read pages 4 to 17.
The other pages are intended for the installer but may be of interest.
About Your Water Heater............................................................................................................ 4
Regular Care ................................................................................................................................ 9
Water Supplies........................................................................................................................... 11
Save A Service Call................................................................................................................... 13
Installation.................................................................................................................................. 18
Heat Pump And Tank Assembly .............................................................................................. 25
Connections –Plumbing .......................................................................................................... 32
Connections –Electrical........................................................................................................... 34
Multiple Installations................................................................................................................. 36
Commissioning.......................................................................................................................... 39
Draining The Water Heater ....................................................................................................... 41
Warranty..................................................................................................................................... 43

4
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.
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.
FREEZE PROTECTION
The water heater has a freeze protection system. The freeze protection system will protect the water heater
from damage, by preventing ice forming in the waterways of the water heater, in the event of freezing
conditions occurring.
If the water temperature at the heat pump heat exchanger falls below 3°C and the heat pump is not
operating, the system will operate the circulator periodically. Water is circulated from the storage tank
through the heat pump circuit, to prevent freezing in the connecting pipe work and heat pump module.
During this freeze protection cycle, the circulator will operate for at least thirty (30) seconds, deactivating
when the water temperature increases above 5°C. The water heater has NO WARRANTY for freeze damage
if power is unavailable at the water heater.
Warning: In areas where the ambient air temperature may fall below 4°C, power must be available to the
water heater at all times to prevent freezing in the heat pump circuit.

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 a 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 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 Rheem Service or their nearest Accredited Service Agent to arrange for an
inspection.
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.
The Rheem 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.
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
OPERATING MODE MONITOR
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 “NORMAL”, indicates the current operating mode (with the red LED off) of the
heat pump water heater and the red LED, marked “ATTENTION”, may indicate a potential fault mode.
The green LED will emit either a solid glow or a series of flashes,
with a 2 second interval between each series. The green LED
may also emit a series of flashes in conjunction with the red LED
to indicate a particular fault condition with the system.
The red LED will emit either a solid glow or a series of flashes,
with a 2 second interval between each series. A series of flashes
indicates there may be a particular fault condition with the
system. A solid glow or 3 flashes (with the green LED off), or
1 flash (with a solid green LED) does not necessarily mean there
is a fault with the system.
The modes are:
Green LED
Red LED
Operational Modes
solid green
(remains on)
off
Standby mode –water is hot
1 x green
off
Call for heating received –system checks performed
Note: if call for heating received, unit may wait and continue flashing until five minutes
has elapsed after its last operation and until the compressor has cooled
2 x green
off
Circulator commences circulation
4 x green
off
Heat pump operation –compressor and fan running
no green
(remains off)
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
Green LED
Red LED
Indicator or Fault Modes
off
Solid red
(remains on)
Ambient temperature < 0°C Heating unit on
off
3 x red
Evaporator < -3°C Heating unit on
solid green
(remains on)
1 x red
Heating stopped due to insufficient flow rate Heating unit off
Notes
Power must be available at the water heater and to the heat pump for the LEDs to glow or flash.
Solid Red or 3 x Red Flashes (Green LED Off) –If the power supply to the water heater is on and the
green LED is off and the red LED is emitting a solid glow or three (3) flashes, this does not necessarily
mean there may be a fault with the water heater but is indicating the water heater is operating outside of
the heat pump‟s operating range. The heat pump‟s operating range is when the ambient air temperature
is 5°C or higher. Refer to “Heat pump operating range” on page 14 in the “Save A Service Call” section
of this Owner‟s Guide.
1 x Red Flash (Solid Green LED) –If the green LED is emitting a solid glow and the red LED is
flashing a single flash, this does not necessarily mean there may be a fault with the water heater. Refer
to “Red and Green LEDs Are Illuminated” on page 16 in the “Save A Service Call” section of this
Owner‟s Guide.
Other Red Flash Sequences –If the red LED emits a series of flashes other than three (3) flashes
(green LED off) or a single flash (green LED solid glow), there may be a fault with the water heater.
Before phoning to arrange a service inspection due to the red LED flashing or the green LED not
illuminating refer to “Heat Pump Is Not Operating” on page 14, “Green and Red LEDs Are Not
Illuminated On Operating Mode Monitor” on page 15, and “Red LED is Illuminated – Green LED is Off”
on page 15 in the “Save A Service Call” section of this Owner‟s Guide.

ABOUT YOUR WATER HEATER
7
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 20, 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.
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. If there is a risk of freezing conditions, the electrical supply to the water heater should not
be switched off, otherwise damage could result (refer to “Freeze Protection” on page 4).
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 main isolating switch to the water heater.
Close the cold water isolation valve at the inlet to the water heater.
Note: If there is a risk of freezing conditions, the electrical supply to the water heater should not be switched
off, otherwise damage could result (refer to “Freeze Protection” on page 4).
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 main isolating switch to the water heater.
Check and if required reset the timer, if one is installed.
The heat pump may take up to 30 seconds to 5 minutes 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 heat pump will commence operating and after a period of time, heating will switch from the heat
pump to the booster heating unit.
If the ambient air temperature is below 0°C and the system calls for heating, the heat pump will not operate
and 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, or if power was switched off whilst the heat pump was operating. The heat
pump will wait at least 5 minutes, and 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.

ABOUT YOUR WATER HEATER
8
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 “Regular Care” on page 9 and to “Anode Inspection and Replacement” on page 11.
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 were 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.
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.
It is not advised to switch off the water heater if there is the risk of freeze conditions. Refer to “To Turn Off
The Water Heater” on page 7.
HOW DO I KNOW IF THE WATER HEATER IS INSTALLED CORRECTLY?
Installation requirements are shown on pages 18 to 23. The water heater must be installed:
by a qualified person, and
in accordance with the installation instructions, and
in compliance with Standards AS/NZS 3500.4, AS/NZS 3000 and all local codes and regulatory authority
requirements.
In New Zealand, the installation must also conform with Clause G12 of the New Zealand Building Code.
VICTORIAN CUSTOMERS
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.
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, its components and fittings. Refer to “Water Supplies” on page 11.
If you are in a known harsh water area or you are not sure of your water chemistry, have your water checked
against the conditions described on pages 11 to 12.
HOW LONG WILL THE WATER HEATER LAST?
The water heater is supported by a manufacturer‟s warranty (refer to page 43). 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. Refer to “Precautions” on page 8.
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 Rheem Service or their nearest Accredited Service
Agent to arrange for an inspection.

9
REGULAR CARE
MINOR SIX MONTH MAINTENANCE
It is recommended minor maintenance be performed every six months by the dwelling occupant.
The minor maintenance includes:
Operate the easing lever on the temperature pressure relief valve. It is very important you raise and
lower the lever gently. Refer to “Temperature Pressure Relief Valve” on page 10.
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.
Operate the easing lever on the expansion control valve (if fitted). It is very important you raise and
lower the lever gently. Refer to “Expansion Control Valve” on page 10.
Check the drain line from the safe tray (if one is installed) is not blocked.
MAJOR FIVE YEAR SERVICE
It is recommended a major five year service be conducted on the water heater. The service must be
conducted by a qualified person. Phone Rheem Service or their nearest Accredited Service Agent.
Note: The five year service and routine replacement of any components, such as the anode and relief
valve(s), are not included in the Rheem warranty. A charge will be made for this work. Only genuine
replacement parts should be used on this water heater.
The major service includes:
Replace the temperature pressure relief valve.
Inspect and flush the expansion control valve (if fitted). If required, replace the valve.
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
Inspection and Replacement” on page 11).
Check the electric heating unit for excessive calcium build up or corrosion and replace if necessary.
Check and clean the heat pump module of dust and residue.
Check and inspect the heat pump module for operation.
Visually check the unit for any potential problems.
Inspect all connections.
Check the condensate drain.
Check the drain line from the safe tray (if one is installed) is not blocked.
Note: The water heater may need to be drained during this service. After the completion of the service, 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.

REGULAR CARE
10
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 16).
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.
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.
If water does not flow freely from the drain line when the lever is
lifted, then the water heater must be checked. Phone Rheem
Service or their nearest Accredited Service Agent to arrange for an
inspection.
The temperature pressure 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 Supplies”
on page 11).
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.
water
heater
drain
line
lift until water
flows from the
drain line –
lower gently