Rheem MPs 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 Split Heat Pump
Water Heater
MPs Series

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 19.
The other pages are intended for the installer but may be of interest.
About Your Water Heater............................................................................................................ 4
Regular Care .............................................................................................................................. 11
Water Supplies........................................................................................................................... 13
Save A Service Call ................................................................................................................... 15
Installation.................................................................................................................................. 20
Heat Pump And Tank Assembly .............................................................................................. 27
Connections –Plumbing .......................................................................................................... 39
Connections –Electrical........................................................................................................... 42
Commissioning.......................................................................................................................... 44
Draining The Water Heater ....................................................................................................... 46
Warranty ..................................................................................................................................... 47

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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.
MODEL TYPE
Your Rheem®air sourced split heat pump storage tank is suitable for indoor or outdoor installation and the
heat pump module designed for outdoor installation only. The model you have chosen is a 561 series model.
This water heater is recommended for connection to a 24 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 air sourced heat pump water heater has a Rheemglas®vitreous enamel lined steel cylinder. The heat
pump module‟s evaporator absorbs heat from the surrounding air and transfers this heat into the water in the
storage tank.
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 side and rear of the heat pump module 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 grille back to atmosphere and the heated water
is circulated back into the storage tank. This process
continues while 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 between a minimum of 3°C to 5°C
and maximum of 45°C to 55°C. The booster heating unit 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 surrounding 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 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 3°C to 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.
At ambient air temperature above 45°C to 55°C, the water heater deactivates the heat pump operation and
switches to the booster heating unit.
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.
The boost capacity of the booster heating unit in a 325 litre storage tank is 180 litres.
Note: The boost capacity of a low watts density or other than a 2.4 kW or 3.6 kW heating unit, if used, is
100 litres.

ABOUT YOUR WATER HEATER
5
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 ambient air temperature falls below 4°C and the heat pump module is not operating, the system will
operate the circulator periodically. During this freeze protection cycle, the circulator will operate for three (3)
minutes and then rest for fifteen (15) minutes, before the cycle is recommenced. Water is circulated from the
storage tank through the heat pump circuit, to prevent freezing in the connecting pipe work and heat pump
module.
Warning: In areas where the ambient air temperature may fall below 0°C, power must be available to the
water heater at all times to prevent freezing in the heat pump circuit.
The system must be installed with the heat pump circuit hot and cold pipes fully insulated with closed cell
polymer insulation with a minimum thickness of 13 mm. Thicker insulation may be required to comply with
the requirements of AS/NZS 3500.4. The water heater has NO WARRANTY for freeze damage if the heat
pump circuit hot and cold pipes are not suitably insulated or if power is unavailable at the water heater.
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 22, 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.
HOW HOT SHOULD THE WATER BE?
The system controls (compressor, evaporator and fan) will operate
until a water temperature of 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.
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
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 flow, air inlet louvres and outlet grille 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.

ABOUT YOUR WATER HEATER
7
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 of the heat pump water heater
and the red LED, marked “ATTENTION”, 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.
The operating modes are:
Flashes
Operating Modes
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
4 x green
Defrost mode –circulator operates for three (3) minutes
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 a possible fault condition
Refer to notes below before calling for service
Notes:
Power must be available at the water heater and to the heat pump for the LEDs to glow or flash.
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 8.
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 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.

ABOUT YOUR WATER HEATER
8
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
Before phoning to arrange a service inspection due to the green LED being off, refer to “Heat Pump
Is Not Operating” on page 16 in the “Save A Service Call” 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 completed and the red LED has gone out. If the red LED has gone
out, when heating is next required the green LED will flash and the heat pump will commence to
operate. If the heat pump stops operating and the red LED recommences to flash, 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 16 in the “Save A Service Call” section of this Owner‟s Guide.
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. The suitability of connection to less than a 24 hour per day power supply is subject to hot
water load, location and climate.
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.
Notes:
This water heater is recommended for connection to a 24 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 5).
A 325 model water heater is not suitable to be connected to a power supply of less than 16 hours per
day. At least 8 hours of power connection should be available during daylight hours.
TO TURN OFF THE WATER HEATER
If you plan to be away from home, we recommend you leave the water heater switched on in the event of
freezing conditions occurring.
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.
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 5).

ABOUT YOUR WATER HEATER
9
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.
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
storage tank 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 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.
Note: The heat pump may not turn on immediately 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.
GOING ON HOLIDAYS
If you plan to be away from home, we recommend you leave the water heater switched on in the event of
freezing conditions occurring (refer to “Freeze Protection” on page 5). If it is necessary to turn off the water
heater, refer to “To Turn Off The Water Heater” on page 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 11 and to “Anode Inspection and Replacement” on page 13.
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.
HOW DO I KNOW IF THE WATER HEATER IS INSTALLED CORRECTLY?
Installation requirements are shown on pages 20 to 25. 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.

ABOUT YOUR WATER HEATER
10
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 13.
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 13 to 14.
HOW LONG WILL THE WATER HEATER LAST?
The water heater is supported by a manufacturer‟s warranty (refer to page 47). 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 9.
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.