Rheem 180 Technical Document

This water heater must be installed and serviced by a qualified person.
Please leave this guide with the householder or responsible officer.
Owner’s Guide
and
Installation Instructions
Solar Thermosiphon Water Heater
Stainless Steel Tanks
WARNING: Plumber –Be Aware
Use copper pipe ONLY. Plastic pipe MUST NOT be used.
It is a requirement of a solar water heater installation that all pipe work be in copper
and not plastic, due to the effects of high water temperatures.

An electronic copy of these Owner’s Guide and Installation Instructions can be downloaded from rheem.com.au.
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.
WARNING: Plumber –Be Aware
•The solar hot and solar cold pipe work between the thermosiphon solar storage tank and the solar
collectors are supplied in the parts kit. The supplied copper solar hot and solar cold pipes MUST BE
used.
•If the solar water heater is installed either on a metal roof or in a trafficable area, such as on an
accessible roof, then the solar hot and solar cold pipesmust be insulated. The solar hot and solar cold
pipes may be required to be insulated to comply with local regulations.
If insulation is required, the full length of the solar hot and solar cold pipes MUST BE insulated.
The insulation must:
◼be of a closed cell type or equivalent, suitable for a solar water heating application and capable
of withstanding the temperature of the water or closed circuit fluid generated by the solar
collectors under stagnation conditions
The specification of the chosen insulation material should be checked with the insulation
manufacturer prior to installation as different materials may vary in temperature tolerance.
◼be at least 13 mm thick
◼be weatherproof and UV resistant
◼be fitted up to and cover the connections on both the solar storage tank and the solar collectors.
The insulation will offer protection to a metal roof against corrosion due to water running off the copper
pipes, assist in avoiding accidental contact with the solar pipe work as very high temperature water
can flow from the solar collectors to the solar storage tank, and also reduce pipe heat losses.
•Plastic pipe MUST NOT be used, as it will not withstand the high temperature and pressure of the
closed circuit fluid (indirect system) and water (direct system) generated by the solar collectors under
stagnation conditions. Failure of plastic pipe can lead to the release of high temperature closed circuit
fluid and water and cause severe water damage and flooding.
•There MUST BE a continuous fall of a minimum 10° in the pipe work from the thermosiphon solar
storage tank to the solar collectors. The highest point of the solar cold pipe and solar hot pipe must
be where they connect to the thermosiphon solar storage tank, otherwise thermosiphoning will not
occur.
•The solar water heater is to be isolated during the testing and commissioning of the heated water
reticulation system in a building, in accordance with Clause 9.3 (a) of AS/NZS 3500.4:2021.

3
CONTENTS
HOUSEHOLDER
This booklet contains important information about your
new water heater, including terms of the Rheem warranty.
We recommend you read pages 8 to 24,
and the terms of the Rheem warranty on pages 4 to 7.
The other pages are intended for the installer but may be of interest.
Warranty..................................................................................................................................4
Safety, Warnings, Installation Notes......................................................................................8
About Your Water Heater......................................................................................................11
Maintenance Requirements..................................................................................................17
Water Supplies......................................................................................................................19
Save A Service Call...............................................................................................................22
Installation.............................................................................................................................25
Installation –Solar Collectors..............................................................................................40
System Assembly .................................................................................................................43
Connections –Plumbing ......................................................................................................56
Connections –Electrical.......................................................................................................60
Multiple Installations.............................................................................................................62
Commissioning.....................................................................................................................64
Draining The Closed Circuit Fluid –52H Series ..................................................................69
Draining and Flushing the Solar Storage Tank....................................................................70
Installation Report.................................................................................................................73
RHEEM AUSTRALIA PTY LTD, A.B.N. 21 098 823 511, www.rheem.com.au
For Service Telephone 131 031 AUSTRALIA

4
RHEEM SOLAR THERMOSIPHON WATER HEATER
WARRANTY –AUSTRALIA ONLY
SOLAR THERMOSIPHON WATER HEATER SYSTEMS –52L, 52H
1. THE RHEEM WARRANTY –GENERAL
1.1 This warranty is given by Rheem Australia Pty Limited ABN 21 098 823 511 of 1 Alan Street, Rydalmere
New South Wales.
1.2 Rheem offer a trained and qualified national service network who will repair or replace components at
the address of the water heater subject to the terms of the Rheem warranty. Rheem Service, in addition
can provide preventative maintenance and advice on the operation of your water heater. The Rheem
Service contact number is 131031, with Contact Centre personnel available 24 hours, 7 days a week to
take your call and if necessary to arrange a service call for during normal working hours Monday to
Friday (hours subject to change).
1.3 For details about this warranty, you can contact us on 131031 or by email at
warrantyenqu[email protected] (not for service bookings).
1.4 The terms of this warranty and what is covered by it are set out in sections 2 and 3 and apply to water
heaters manufactured after 1st September 2014.
1.5 If a subsequent version of this warranty is published, the terms of that warranty and what is covered by
it will apply to water heaters manufactured after the date specified in the subsequent version.
2. TERMS OF THE RHEEM WARRANTY AND EXCLUSIONS TO IT
2.1 The decision of whether to repair or replace a faulty component is at Rheem’s sole discretion.
2.2 If you require a call out and we find that the fault is not covered by the Rheem warranty, you are
responsible for our standard call out charge. If you wish to have the relevant component repaired or
replaced by Rheem, that service will be at your cost.
2.3 Where a failed component or cylinder is replaced under this warranty, the balance of the original
warranty period will remain effective. The replacement does not carry a new Rheem warranty.
2.4 Where the water heater is installed outside the boundaries of a metropolitan area as defined by Rheem
or further than 25 km from either a regional Rheem branch office or an Accredited Rheem Service
Agent's office, the cost of transport, insurance and travelling between the nearest branch office or
Rheem Accredited Service Agent’s office and the installed site shall be the owner’s responsibility.
2.5 Where the water heater is installed in a position that does not allow safe or ready access, the cost of
that access, including the cost of additional materials handling and/or safety equipment, shall be the
owner’s responsibility. In other words, the cost of dismantling or removing cupboards, doors or walls
andthe cost of any special equipment to bringthe water heater to floor or ground level or to a serviceable
position is not covered by this warranty.
2.6 This warranty only applies to the original and genuine Rheem water heater in its original installed location
and any genuine Rheem replacement parts.
2.7 The Rheem warranty does not cover faults that are a result of:
a) Accidental damage to the water heater or any component (for example: (i) Acts of God such as
floods, storms, fires, lightning strikes and the like; and (ii) third party acts or omissions).
b) Misuse or abnormal use of the water heater.
c) Installation not in accordance with the Owner’s Guide and Installation Instructions or with relevant
statutory and local requirements in the State or Territory in which the water heater is installed.
d) Connection at any time to a water supply that does not comply with the water supply guidelines as
outlined in the Owner’s Guide and Installation Instructions.

RHEEM SOLAR THERMOSIPHON WATER HEATER
WARRANTY –AUSTRALIA ONLY
5
SOLAR THERMOSIPHON WATER HEATER SYSTEMS –52L, 52H
e) Repairs, attempts to repair or modifications to the water heater by a person other than Rheem
Service or a Rheem Accredited Service Agent.
f) Faulty plumbing or faulty power supply.
g) Failure to maintain the water heater in accordance with the Owner's Guide and Installation
Instructions.
h) Transport damage.
i) Fair wear and tear from adverse conditions (for example, corrosion).
j) Cosmetic defects.
k) Breakage of collector glass for any reason including hail damage (we suggest that the collector
glass be covered by your home insurance policy).
l) Ice formation in the waterways of a: direct open circuit thermosiphon system; or an indirect closed
circuit thermosiphon system due to non Rheem approved or incorrectly mixed closed circuit fluid
being used.
m) Non Rheem approved or incorrectly mixed closed circuit fluid being used or incorrect or insufficient
filling of the closed circuit system with the closed circuit fluid.
2.8 Subject to any statutory provisions to the contrary, this warranty excludes any and all claims for damage
to furniture, carpet, walls, foundations or any other consequential loss either directly or indirectly due to
leakage from the water heater, or due to leakage from fittings and/ or pipe work of metal, plastic or other
materials caused by water temperature, workmanship or other modes of failure.
2.9 If the water heater is not sized to supply the hot water demand in accordance with the guidelines in the
Rheem water heater literature, any resultant fault will not be covered by the Rheem warranty.
3. WHAT IS COVERED BY THE RHEEM WARRANTY
FOR THE WATER HEATERS DETAILED IN THIS DOCUMENT
3.1 Rheem will repair or replace a faulty component of your water heater if it fails to operate in accordance
with its specifications as follows:

RHEEM SOLAR THERMOSIPHON WATER HEATER
WARRANTY –AUSTRALIA ONLY
6
SOLAR THERMOSIPHON WATER HEATER SYSTEMS –52L, 52H
What components
are covered
The period from the date
of installation in which
the fault must appear in
order to be covered
What coverage
you receive
All Systems (all installations)
All components
Year 1
Repair and/or replacement of the faulty
component, free of charge, including labour.
52H/SP Series Systems
The cylinder
(if the water heater is
installed in a single-family
domestic dwelling)
Years 2 to 7
Replacement cylinder, free of charge.
Installation and repair labour costs are the
responsibility of the owner.
The cylinder
(if the water heater is not
installed in a single-family
domestic dwelling)
Years 2 & 3
Replacement cylinder, free of charge.
Installation and repair labour costs are the
responsibility of the owner.
The solar collector
(all installations)
Years 2 to 5
Replacement solar collector, free of charge.
Installation and repair labour costs are the
responsibility of the owner.
52L/NPT, 52H/NPT Series Systems
(if the water heater is installed in a single-family domestic dwelling)
The cylinder and
solar collector(s)
Years 2 & 3
Replacement cylinder or solar collector, free
of charge, including labour.
Years 4 to 7
Replacement cylinder or solar collector, free
of charge. Installation and repair labour
costs are the responsibility of the owner.
52L, 52H / L & CS07 Series Systems
(if the water heater is installed in a single-family domestic dwelling)
All components
Year 2 to 5
Repair and/or replacement of the faulty
component, free of charge, including labour.
The cylinder and
solar collector(s)
Years 6 to 10
Replacement cylinder or solar collector, free
of charge. Installation and repair labour
costs are the responsibility of the owner.
52L, 52H / NPT, L & CS07 Series Systems
(if the water heater is not installed in a single-family domestic dwelling)
The cylinder and
solar collector(s)
Years 2 & 3
Replacement cylinder or solar collector, free
of charge. Installation and repair labour
costs are the responsibility of the owner.
Year 4
Replacement cylinder or solar collector,
supplied at 75% of list price. Installation and
repair labour costs and 25% of cylinder or
solar collector list price are the responsibility
of the owner.
Year 5
Replacement cylinder or solar collector,
supplied at 50% of list price. Installation and
repair labour costs and 50% of cylinder or
solar collector list price are the responsibility
of the owner.

RHEEM SOLAR THERMOSIPHON WATER HEATER
WARRANTY –AUSTRALIA ONLY
7
SOLAR THERMOSIPHON WATER HEATER SYSTEMS –52L, 52H
4. ENTITLEMENT TO MAKE A CLAIM UNDER THIS WARRANTY
4.1 To be entitled to make a claim under this warranty you need to:
a) Be the owner of the water heater or have consent of the owner to act on their behalf.
b) Contact Rheem Service without undue delay after detection of the defect and, in any event, within
the applicable warranty period.
4.2 You are not entitled to make a claim under this warranty if your water heater:
a) Does not have its original serial numbers or rating labels.
b) Is not installed in Australia.
5. HOW TO MAKE A CLAIM UNDER THIS WARRANTY
5.1 If you wish to make a claim under this warranty, you need to:
a) Contact Rheem on 131031 and provide owner’s details, address of the water heater, a contact
number and date of installation of the water heater or if that’s unavailable, the date of manufacture
and serial number (from the rating label on the water heater).
b) Rheem will arrange for the water heater to be tested and assessed on-site.
c) If Rheem determines that you have a valid warranty claim, Rheem will repair or replace the water
heater in accordance with this warranty.
5.2 Any expenses incurred in the making of a claim under this warranty will be borne by you.
6. THE AUSTRALIAN CONSUMER LAW
6.1 Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are
entitled to a replacement or refund for a major failure and for compensation for any other reasonably
foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods
fail to be of acceptable quality and the failure does not amount to a major failure.
6.2 The Rheem warranty (set out above) is in addition to any rights and remedies that you may have under
the Australian Consumer Law.

8
SAFETY, WARNINGS, INSTALLATION NOTES
It is important you read the following safety and warnings information.
SAFETY AND WARNINGS
•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.
•If the electrical conduit to the solar storage tank 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.
•This water heater uses 220 V - 240 V a.c. electrical power for operation of the control systems and the
electrically operated components. The removal of the side cover will expose 220 V - 240 V a.c. wiring. It
must only be removed by a qualified person.
•This water heater is supplied with a thermostat, over-temperature cut-out, a combination temperature
pressure relief valve and a 52H series model also has a closed circuit 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 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.
•DANGER: The operation of the over-temperature cut-out on a 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.
•Do not touch any exposed pipe work or fittings connecting the solar storage tank and the solar collectors,
as this may result in a burn injury. Very high temperature closed circuit fluid or hot water and in some
circumstances high temperature steam can be generated by the solar collectors under certain conditions
and this flows through the pipe work from the solar collectors to the solar storage tank.
Note: Any exposed pipe work or fittings in the collectorcircuit where the installation is in a trafficable area,
such as on an accessible roof, should be attended to and covered with insulation. Phone Rheem Service
or their nearest Accredited Service Agent to arrange for an inspection.
•Do not remove the closed circuit relief valve (52H series model) as there may be a very high scalding risk
present. When operating in daylight, the heat exchange circuit will be pressurised and can contain
superheated fluid and may contain steam. At other times, the circuit may be pressurised and contain high
temperature fluid.
•Should the waterfrom a 52H series water heater appear blue orif blue closed circuit fluid is noticedaround
the base of the water heater or solar collectors, this indicates a leak of the closed circuit fluid from the heat
exchanger or the solar collectors. The closed circuit fluid is non-toxic and not hazardous to health. Phone
Rheem Service or their nearest Accredited Service Agent to arrange for an inspection.
•The water heater under normal use and summer solar conditions shouldheat the water inthe solar storage
tank to 60°C to 75°C. This water temperature can be exceeded and reach up to 95°C during periods of
high solar radiation conditions and reduced hot usage. During times of low solar energy gain or if boosting
of the water temperature is required, an electric heating unit will heat the water temperature to 60°C or up
to 70°C depending upon the thermostat setting.
Refer to “Solar Operation” on page 11 and to “How Hot Should The Water Be?” on page 12.
•For continued safety of this water heater it must be installed, operated and maintained in accordance with
the Owner’s Guide and Installation Instructions.
•Servicing of a water heater must only be carried out byqualified personnel. Phone Rheem Service or their
nearest Accredited Service Agent.

SAFETY, WARNINGS, INSTALLATION NOTES
9
•The lever on the temperature pressure relief valve and expansion control valve requires to be operated
every six (6) months to clear any deposits and to ensure the valve and its drain line are not blocked.
Refer to “Relief Valves” on page 10 and “Minor Maintenance Every Six Months” on page 17.
•Only a person qualified to install or service a water heater can drain the water heater, if this is required.
•Do not modify this water heater.
•The 52H closed circuit system has freeze protection. The amount of closed circuit concentrate supplied
with this water heater provides protection in frost prone areas to a certain temperature. The table on
page 65 lists the percentage of Coolblend concentrate fluid in the closed circuit of each system and the
recommended minimum ambient temperature for thesystem, forthe number of bottles supplied with each
system. Refer to “Freeze Protection”on page 13.
•The 52L open circuit system does not have freeze protection. The system is not suitable for installation in
areas subject to frost or freeze conditions.
INSTALLATION NOTES
This water heater must be installed:
•by a qualified person,
•in accordance with the installation instructions,
•in compliance with the Plumbing Code of Australia (PCA) and Plumbing Standard AS/NZS 3500.4,
▪This water heater is designed for outdoor installation.
▪This water heater is intended to be permanently connected to the water mains and not connected by
a hose-set. A braided flexible hose or semi-flexible connector may be usedforconnection tothe water
heater, where permitted by AS/NZS 3500.4.
•in compliance with the Australian / New Zealand Wiring Rules AS/NZS 3000,
▪Isolation switches must be installed in the electrical circuit to the water heater in accordance with the
Wiring Rules, so the water heater can be switched off.
▪The power supply wires are to be directly connected to the terminal block and earth tab connection,
with no excess wire loops inside the front cover. The temperature rating of the power supply wires
insulation must suit this application, or the wiring protected by insulating sleeving with an appropriate
temperature rating if it can make contact with the internal storage cylinder. The temperature of the
internal storage cylinder can reach 95°C during its operation.
•in compliance with all local codes and regulatory authority requirements.
Installation and commissioning requirements and details for the installing plumber and licensed electrical
worker are contained on pages 25 to 68.
Mains pressure water supply
The water heater is designed to operate at mains pressure by connecting directly to the mains water supply.
The water heater is supplied with a temperature pressure relief valve with a pressure rating of 850 kPa and an
expansion control valve with a pressure rating of 700 kPa.
The maximum mains water supply pressure for the water heater is 680 kPa when an expansion control valve
is installed. If the mains supply pressure in your area exceeds this value, a pressure limiting valve must be
installed.
The supply pressure should be greater than 350 kPa for true mains pressure operation to be achieved.

SAFETY, WARNINGS, INSTALLATION NOTES
10
RELIEF VALVES
Temperature Pressure Relief Valve
This water heater incorporates a temperature pressure relief
valve located near the top of the solar storage tank. This valve
is essential for the water heater’s safe operation.
It is possible for the valve to discharge a quantity of water
through the drain line during each heatingperiod. This quantity
should be equal to approximately 1/50 of the hot water used,
as water expands by this volume when heated.
Expansion Control Valve
In many areas, including South Australia and scaling water
areas, it is mandatory an expansion control valve is fitted to
the cold water line to the water heater.
The expansion control valve will discharge the quantity of
water from its drain line during the heating period instead of
the temperature pressure relief valve as it has a lower
pressure rating.
Valve Operation
Continuous leakage of water from either valve and its drain
line may indicate a problem with the water heater. Refer to
“Temperature Pressure Relief Valve or Expansion Control
Valve Running” on page 23.
Warning: Never block the outlet of either valve or their
drainlinesfor any reason. A relief valve drainmust be left open
to atmosphere, and be installed in a continuously downward
direction.
In locations where water pipes are prone to freezing, the relief valve drain line must be insulated and not
exceed 300 mm in length before discharging into a tundish through an air gap.
The easing lever on the temperature pressure relief valve and expansion control valve should be operated
once every six (6) months to clear any deposits and ensure the valve and its drain line are not blocked. It is
very important the lever is raised and lowered gently. Refer to “Minor Maintenance Every Six Months” on
page 17.
If the relief valve easing lever is not readily and safely accessible, contact Rheem Service or their nearest
Accredited Service Agent. Do not attempt to climb onto a non-trafficable roof to operate the relief valve lever.
Warning: Water discharged from the temperature pressure relief valve drain line will be hot. Exercise care
to avoid any splashing of water by standing clear of the drain line’s point of discharge when operating either
valve’s easing lever.
DANGER: Failure to operate the easing lever on the relief valve once every six (6) months may result in
the solar storage tank 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 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 five (5) years and the
expansion control valve should be checked for performance or replaced at intervals not exceeding
five (5) years. The checking of the valves performance or replacement should occur more frequently in areas
where there is a high incidence of water deposits. Refer to “Water Supplies” on page 19.
outlet /
drain line
lift until water
flows from the
drain line –
lower gently

11
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®thermosiphon solar water heater is designed for both the solar collectors and the solar storage
tank to be roof mounted. The solar storage tank has a Colorbond®jacket. The 52L tank (direct system) is
suitable for installation with NPT200, L or CSA2007 solar collectors and the 52H tank (indirect system) is
suitable for installation with SPA2000, NPT200, L or CSA2007 solar collectors.
The 52L series systems do not have freeze protection. These systems are not suitable for installation in areas
subject to frost orfreeze conditions. Freezeconditions occur below 6°C.These systems haveNO WARRANTY
for freeze damage (refer to “Terms of the Rheem Warranty” on page 4).
The 52H series systems are suitable for installation in areas subject to frost or freeze conditions. Freeze
conditions occur below 6°C. These systems have NO WARRANTY for freeze damage if non Rheem approved
closed circuit fluid has been used or if the closed circuit fluid has been incorrectly mixed (refer to “Terms of the
Rheem Warranty” on page 4).
This water heater is designed to be installed as an electric boosted solar water heater with its booster heating
unit connected to a power supply, however it may be installed with an in-series continuous flow or storage
booster.
If this water heater is installed with an in-series booster, then the electric booster heating unit will not be
connected to a power supply and the references to the electric booster heating unit, thermostat and boosting
controls in this Guide will not be applicable to the installation. For information relating to the function and
operation of the in-series booster, refer to the Owners Guide and Installation Instructions supplied with the
booster water heater.
SOLAR OPERATION
The Rheem solar thermosiphon system has its stainless steel solar storage tank installed on the roof directly
coupled to the solar collectors. The 52L series are direct solar hot water systems and the 52H series are
indirect solar hot water systems with a heat exchanger in the solar storage tank.
The solar water heater uses the thermosiphon principle, without the need for a pump, circulator or sensors. It
works on the simple scientific fact that hot fluid rises. The solar collector’s low-iron content solar glass allows
more solar energy from the sun to pass through and be used to heat the collector’s absorber plate than
conventional glass. As the sun heats the water or closed circuit fluid in the solar collectors, the increase in
temperature causes the fluid to risethrough a copper pipe into the storage tank (52L series) or heat exchanger
(52H series) where it transfers its heat into the water in the solar storage tank. This allows cooler fluid from the
storage tank or heat exchanger to flow into the solar collectors to be heated by the sun’s energy. This process
continues while solar energy is available.
52L series: The solar storage tank and solar collectors are
connected by copper pipe work and form an open circuit which is
filled with potable water.
52H series: The heat exchanger and solar collectors are
connected by copper pipe work and form a closed circuit which is
filled with closed circuit fluid. The closed circuit fluid is a solution of
a blue, non-toxic food grade propylene glycol concentrate mixed
with water. The closed circuit concentrate is used to lower the
freezing temperature of the closed circuit fluid and provides
protection against freezing. The closed circuit also provides
protection to the solar collectors and solar pipe work against harsh
water chemistry.
Automatic safety controls are fitted to the water heater to provide
safe and efficient operation.

ABOUT YOUR WATER HEATER
12
ELECTRIC BOOSTING
Water stored in the solar storage tank can be heated by an electric booster heating unit. The booster heating
unit is for heating the water at times of low solar energy gain, such as during very cloudy or rainy weather, or
during the colder months.
The amount of water heated by the raised booster heating unit of the thermosiphon solar storage tank is
90 litres (180 tank) or 150 litres (300 tank).
The thermosiphon solar water heater is most suited for the booster heating unit to be connected to either a
continuous, or a time of use, or an extended Off-Peak (overnight and day) electricity supply. A timer can also
be used to control the boosting periods and help maximise solar savings. Refer to “Booster Control” on
page 14.
The booster heating unit may be connected to an Off-Peak (overnight) electricity supply, however this will only
allow the booster to heat the water overnight. If this type of connection is considered, care must be taken to
ensure there is sufficient boost capacity to meet the household’s full day and night’s hot water supply during
periods of no or low solar gain, particularly in cold weather. There is also an increased risk of temperature run
down occurring, particularly in cooler weather (refer to “Temperature Redistribution”on page 23).
The booster heating unit is controlled by anelectricthermostat. Thethermostat and its over temperature energy
cut out are mounted on the solar storage tank behind the front cover. The water temperature is automatically
controlled to the thermostat setting when the booster heating unit is energised.
HOW HOT SHOULD THE WATER BE?
The temperature the system will operate at under solar radiation will
depend upon the level of solar radiation available, orientation and
inclination of the solar collectors, incoming cold water temperature
and volume of hot water used.
Under normal household use and average operating conditions, the
system may achieve a water temperature of approximately twice the
maximum daily outside air temperature. In summer solar conditions
this can be up to 60°C to 75°C. This water temperature can be
exceeded and reach up to 95°C during periods of high solar
radiation conditions and reduced hot usage.
During periods of low solar energy gain, the water temperature can
be boosted by the thermostatically controlled electric booster
heating unit. Refer to “Booster Control” on page 14.
Rheem recommends the thermostat is set at 60°C to maximise solar
contribution.
Note: AS 3498 requires that a water heater provides the means to inhibit the growth of Legionella bacteria in
potable water. This water heater can satisfy this AS 3498 requirement provided the electric booster is
energised for a sufficient period each day and the electric booster thermostat setting is 60°C or higher.
If this water heater is installed with an in-series continuous flow gas booster, then this requirement of AS 3498
can be satisfied provided the booster is energised, its preset outlet temperature setting is 70°C or higher and
a remote temperature controller is not used.
If this water heater is installed with an in-series storage booster, then this requirement of AS 3498 can be
satisfied provided the storage booster is energised and its thermostat setting is 60°C or higher.
HOTTER WATER INCREASES THE RISK OF SCALD INJURY
This water heater can deliver hot water at temperatures which on occasion could exceed 75°C, sufficiently hot
to cause severe scalding. Water at this temperature may have been plumbed to fixtures where water hotter
than 50°C is allowed, such as the kitchen and laundry.
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.
maximum booster setting
maximum recommended
supply temperature to
bathrooms and ensuites
minimum booster setting
typical maximum temperature
from solar gain

ABOUT YOUR WATER HEATER
13
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 water heater features a tradesperson adjustable thermostat. This requires a licensed electrical worker to
make any temperature adjustments. The thermostat has a maximum temperature setting of 70°C and a
minimum temperature setting of 60°C.
We advise you to have a licensed electrical worker adjust the thermostat to the lowest setting which meets
your needs, especially if there are young children or elderly people in the home. Refer to “Hotter Water
Increases the Risk of Scald Injury” on page 12.
PRECAUTIONS
The water heater must be maintained in accordance with the Owner’s Guide and Installation Instructions. Refer
to “Maintenance Requirements” on page 17.
If this water heater is to be used where an uninterrupted hot water supply is necessary for your application or
business you should ensurethat you have back upredundancy within the hot water system design. This should
ensure the continuity of hot water supply in the event that this water heater wereto 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.
FREEZE PROTECTION
The 52H series solar water heaters are an indirect closed circuit solar hot water system with aheat exchanger
in the solar storage tank. The heat exchanger and solar collectors form a closed circuit and are filled with
closed circuit fluid. The closed circuit fluid is a solution of a blue, non-toxic food grade propylene glycol
concentrate mixed with water. The closed circuit concentrate is used to lower the freezing temperature of the
closed circuit fluid and provides protection against freezing.
During installation, the closed circuit concentrate is blended with water. The amount of closed circuit
concentrate supplied with this water heater provides protection in frost prone areas to a certain temperature.
The table on page 65 lists the percentage of Coolblend concentrate fluid in the closed circuit of each system
and the recommended minimum ambient temperature for the system, for the number of bottles supplied with
each system. If a lower temperature protection is anticipated, additional Coolblend concentrate will be required
to provide a greater concentration in the closed circuit fluid.
The system has NO WARRANTY for freeze damage if non Rheem approved closed circuit fluid has been used
or if the closed circuit fluid has been incorrectly mixed (refer to “Terms of the Rheem Warranty” on page 4).
Note: The 52L series systemsdo not have freeze protection. The system is not suitable for installation in areas
subject to frost or freeze conditions. Freeze conditions occur below 6°C. The system has NO WARRANTY for
freeze damage (refer to “Terms of the Rheem Warranty” on page 4).
CLOSED CIRCUIT JACKET RELIEF VALVE
The tank’s closed circuit heat exchange jacket has a relief valve located in the vent pipe of the jacket. This
relief valve is to prevent over-pressurisation of the closed circuit either due to incorrect filling or abnormal
operating conditions.
During the water heater's first few months of operation, a small amount of fluid may discharge from the relief
valve until the ideal closed circuit fluid volume is established. Discharges from the valve after this time could
indicate the water heater is not operating efficiently. Under thesecircumstances phone Rheem Service or their
nearest Accredited Service Agent to arrange for an inspection. Do not attempt to service the water heater
yourself.
Do not remove the closed circuit relief valve as there may be a very high scalding risk present. When operating
in daylight, the heat exchange circuit will be pressurised and can contain superheated fluid and may contain
steam. At other times, it may be pressurised and contain high temperature fluid.

ABOUT YOUR WATER HEATER
14
BOOSTER CONTROL
An isolating switch is installed in the electrical meter box for an electrically in-tank boosted solar storage tank.
This should be left switched on to allow the booster heating unit to operate if required. The booster heating
unit is for heating the water at times of low solar energy gain, such as during very cloudy or rainy weather, or
during the colder months. The booster heating unit will only activate if heating is required and power is available
from the switchboard. When the water is below the thermostat setting, the booster heating unit will turn on and
heat the water. The booster heating unit will automatically turn off when the temperature of the water reaches
the thermostat setting.
Leaving the isolating switch switched on will also provide a sufficient period of time each day for the booster
heating unit to operate, if required, to satisfy the requirements of AS 3498.
The amount of water heated by the raised booster heating unit of the solar storage tank will be 150 litres
(300 litre model), or 90 litres (180 litre model).
Timer Control Switch
A suitably rated timer control switch can be installed and will help maximise energy savings with an electrically
boosted solar water heater connected to a continuous, time of use or extended Off-Peak (overnight and
day) electricity supply. Further information for a licenced electrical worker on the recommended methods of
wiring the timer are outlined in “Booster Control” on page 61.
Programming the Timer
Power must be available to the timer control switch before the booster heating unit can be activated. The timer
should be programmed:
•to suit the hot water consumption pattern of the household,
•with the end of the period to coincide with the commencement of the evening hot water usage,
A second period, such as prior to the morning hot water usage, may be necessary.
•to enable a boosting period of not less than therecommended continuous length of time for boosting, and
•for a period when power will be available to the timer.
Note: When daylight saving time applies, you may consider resetting the timer accordingly.
The recommended continuous length of time for boosting is:
Booster heating unit size
Model
Minimum winter
cold water temperature
Temperature
rise
2.4 kW
3.6 kW
4.8 kW
180
Cool / temperate climate
10°C
50°C
2 ¼ hours
1 ½ hours
1 ¼ hours
Temperate / sub-tropical climate
15°C
45°C
2 hours
1 ½ hours
1 hour
Tropical climate
20°C
40°C
1 ¾ hours
1 ¼ hours
1 hour
300
Cool / temperate climate
10°C
50°C
3 ¾ hours
2 ½ hours
2 hours
Temperate / sub-tropical climate
15°C
45°C
3 ½ hours
2 ¼ hours
1 ¾ hours
Tropical climate
20°C
40°C
3 hours
2 hours
1 ½ hours
The recommended boosting periods are sufficientto allow the booster heating unit to heat up the boost volume
of the solar storage tank to 60°C where the winter cold water temperatures do not fall below those shown. This
may be necessary during periods of very low solar energy gain through the solar collectors, such as during
constant rain or extremely cloudy weather, particularly in winter when the incoming cold water temperature is
lower. The period will also provide a sufficient heat up time for the electric booster to operate, if required, to
satisfy the requirements of AS 3498.
The booster heating unit will only activate if heating is required and power is available from the timer. When
the water is below the thermostat setting, the booster heating unit will turn on and heat the water. The booster
heating unit will automatically turn off either when the temperature of the water reaches the thermostat setting
or at the end of the timer period, whichever comes first.

ABOUT YOUR WATER HEATER
15
RAINWATER COLLECTION SYSTEM
If the 52H series solar water heater is installed on a section of roof which is part of a rainwater collection
system, then it is recommended this section of roof and its gutter be isolated from the rainwater collection
system.
The closed circuit fluid acts as an anti-freeze agent and rust inhibitor, is non-toxic to humans and is harmless
to the environment. However it does have an adverse effect on water stored in rainwater tanks. It will kill
microscopic algae typically present in rainwater tanks and cause an unpleasant odour to develop. This will
result in the rainwater tank having to be drained and cleaned.
If a rainwater tank does become contaminated with closed circuit fluid, then the following actions should be
undertaken by a qualified person. Additional actions may be necessary to return the water supply to a
consumable state.
•Correct the leak or spillage.
•Wash down the roof area where the spill or leak has occurred.
•Flush out the gutters and down pipes.
•Determine how the closed circuit fluid made its way intothe rainwater tank. If the section of roof supporting
the solar water heater is not isolated from the rainwater collection system, then this should be remedied.
•Empty the rainwater tank, and clean out all algae from the inside of the tank.
•Refill the rainwater tank with fresh water.
Refer to “Rainwater Collection System” on page 28 for additional information.
TO TURN OFF THE WATER HEATER
If you plan to be away from home for 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 to the solar storage tank at the hot water isolating switch on the switch
board.
•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 at the inlet to the water heater.
•Switch on the electrical supply to the solar storage tank at the hot water isolating switch on the switch
board.
•Check and if required reset the timer, if one is installed.
GOING ON HOLIDAYS
If you plan to be away from home, conserve energy by switching the booster switch “OFF”. Refer to “To Turn
Off the Water Heater” on page 15. Also if the system is not used for a period in excess of 2 weeks it is
recommended the solar collectors be covered.
Care should be taken when returning from holidays and the collectors have not been covered. The water in
the storage tank can be very hot.

ABOUT YOUR WATER HEATER
16
VICTORIAN CUSTOMERS
Notice to Victorian Customers from the Victorian Building Authority. 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 19.
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 19 to 21.
HOW LONG WILL THE WATER HEATER LAST?
The water heater is supported by a manufacturer’s warranty (refer to page 4). 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 13.

17
MAINTENANCE REQUIREMENTS
MINOR MAINTENANCE EVERY SIX MONTHS
It is recommended minor maintenance be performed every six (6) months. Minor maintenance can be
performed by the dwelling occupant.
The minor maintenance includes:
•If readily and safely accessible, operate the easing lever on the temperature pressure relief valve. It is
very important the lever is raised and lowered gently. Refer to “Relief Valves” on page 10.
If the relief valve lever is not readily and safely accessible, contact Rheem Service or their nearest
Accredited Service Agent. Do not attempt to climb onto a non-trafficable roof to operate the relief valve
lever.
Warning: Water discharged from the temperature pressure relief valve drain line will be hot. Exercise
care to avoid any splashing of water by standing clear of the drain line’s point of discharge when operating
the valve’s easing lever.
•If readily and safely accessible, operate the easing lever on the expansion control valve. It is very
important the lever is raised and lowered gently. Refer to “Relief Valves” on page 10.
If the relief valve lever is not readily and safely accessible, contact Rheem Service or their nearest
Accredited Service Agent. Do not attempt to climb onto a non-trafficable roof to operate the relief valve
lever.
MAJOR SERVICE EVERY FIVE YEARS
It is recommended a major service be conducted on the water heater every five (5) years.
Warning: Servicing of a water heater must only be carried out by a qualified person. Phone Rheem Service
or their nearest Accredited Service Agent.
Note: The major service and routine replacement of any components, such as the relief valves, 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 the following actions:
•Replace the temperature pressure relief valve.
•Inspect and flush the expansion control valve. If required, replace the valve.
•Check the booster heating unit for excessive calcium build up or corrosion and replace if necessary.
•Drain, check and refill or replace (if required) the closed circuit fluid (52H series).
•Flush and bleed the solar collectors (52L series).
•Drain and flush the solar storage tank of sediment build-up if required.
•Clean the collector glass.
•Visually check the unit for any potential problems, e.g. broken glass, excessive dust and dirt build-up,
shading.
•Check the condition of the pipe insulation, if fitted, on the solar hot and solar cold pipes. Replace or make
good if required.
•Inspect all connections.
Note: The solar storage tank may need to be drained during this service. After the completion of the service,
the solar storage tank will take some time to reheat thewater by solar gain. Depending upon the power supply
connection to the booster heating unit, hot water may not be available until the next day.

MAINTENANCE REQUIREMENTS
18
If a temperature limiting device, water filter or a water softener are installed, their operation should be checked
at this time. These checks are not covered within the major service. Components, devices and valves which
are not part of the water heater, such as a temperature limiting device, pipe insulation, water filter and water
softener are not covered by the Solahart warranty.
COLLECTOR GLASS
Ensure the glass on your solar collectors is free of dust, salt spray or any other matter which may reduce the
effectiveness of the solar collectors. Rainfall should keep the collector adequately clean. It is recommended
the collector glass be washed clean at least every three months should adequate rain not have fallen in this
period.
Collector glass can be hosed down or if the solar collectors are accessible such as on a trafficable roof, wash
the collector glass with water and a soft brush when the solar collectors are cool, such as early in themorning.
In extremely dusty areas, such as mining towns and locations adjacent to dust forming plants, extra attention
may need to be given to keeping the collector glass clean.
Have any trees trimmed which may shade the solar collectors.
Rheem solar collectors have passed the AS/NZS 2712 requirements for resistance to hailstone damage, so it
is not normally necessarytofit a guardto acollector. Stone Guards are available to provide a level of protection
to the collectors against vandalism or accidental damage. Contact Rheem or your local Rheem Solar Water
Heater Distributor for details.

19
WATER SUPPLIES
This water heater must be installed in accordance with this advice to be covered by the Rheem
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 Rheem 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 water heater cylinder, a heat exchanger in an indirect solar water heater system,
a temperature pressure relief valve, a heating unit and a solar collector in a direct solar water heater system.
Where there is a changeover from onewater 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 Rheem warranty to apply.
CHLORIDE AND PH
In a high chloride water supply, the water can corrode stainless steel parts and cause them to fail.
Where the chloride level exceeds 250 mg/L the Rheem warranty does not apply to a stainless steel cylinder
or a heat exchanger in a 52H cylinder.
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.
Where the pH is less than 6.0 the Rheem warranty does not apply to a stainless steel cylinder or a heat
exchanger in a 52H cylinder. 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. This may result in pH of less than 6.0. It is recommended an analysis on the water
from a rainwater tank be conducted prior to connecting this type of water supply to a water heater with a
stainless steel cylinder.
Refer to the pH and Chloride chart on page 19.
0
no warranty applies to a:
-stainless steel water heater cylinder
WITHIN WARRANTY
SPECIFICATION
4.0 5.0 6.0 7.0 8.0 9.0
350
300
250
200
150
100
50
CHLORIDE -mg/L
pH & CHLORIDE
SOLAR WATER HEATERS (stainless steel cylinder)
acidic alkaline
pH
no warranty applies to a:
-stainless steel water heater cylinder

WATER SUPPLIES
20
SATURATION INDEX
The saturation index is used as a measure of the water’s corrosive or scaling properties. The saturation index
figures stated are calculated using a water temperature of 80°C.
In a corrosive water supply, the 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 Rheem warranty does not apply to a copper
sheathed heating unit or a solar collector in a direct solar water heater system. A corrosion resistant heating
and an indirect solar water heater must be used unit must be used for the Rheem warranty to apply to the
heating unit and solar collector. This water heater is supplied fitted with a corrosion resistant heating unit.
In a scaling water supply calcium carbonate is deposited out of the water onto any hot metallic surface.
Where the saturation index exceeds+0.40, the water is very scaling. An expansion control valve must be fitted
on the cold water line after the non-return valve to protect and for the Rheem warranty to apply to the
temperature pressure relief valve and water heater cylinder. Solar collectors in a direct solar water heater
system should be covered when the water heater is not intended to be used for more than two weeks.
Where the saturation index exceeds +0.80, the Rheem warranty does not apply to a standard watts density
heating unit or a solar collector in a direct solar water heater system. A low watts density heating unit or an
indirect solar water heater must be used for the Rheem warranty to apply to the heating unit or solar collector.
Water which is scaling maybetreated witha water softening device to reducethe saturation indexof the water.
Refer to the Saturation Index chart on page 20. Refer to the cold water connection detail on page 56 for the
position of the expansion control valve.
Contact Rheem Service or their nearest Accredited Service Agent if a replacement heating unit is required.
very corrosive very scalingscaling
corrosive
+0.4 +0.80-1.0
no warranty applies to a:
temperature pressure relief valve
or a water heater cylinder unless
an expansion control valve is fitted.
no warranty applies to a:
-copper sheathed heating unit -direct (open circuit) solar collector
SATURATION INDEX (SI)
SOLAR WATER HEATERS WITH ELECTRIC HEATING UNIT
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
no warranty applies to a:
-standard watts density heating unit -direct (open circuit) solar collector