Rheem Solar Thermosiphon Water Heater 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.

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 pipe 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 pipes must 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, however thicker insulation may be required to comply with the
requirements of AS/NZS 3500.4
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 corrosion protection to a metal roof against water runoff over the copper
pipe, assist in avoiding accidental contact with the solar pipe work as high temperature water or
closed circuit fluid 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 temperature and pressure of the closed
circuit fluid (indirect system) and water (direct system) generated by the solar collectors under
stagnation conditions. The solar collectors can generate extremely high water or closed circuit fluid
temperatures up to 150°C and high water pressure of 850 kPa. Plastic pipe cannot withstand these
temperatures and pressures and MUST NOT be used. 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 11.1 and 11.3 (a) of AS/NZS 3500.4.

3
CONTENTS
HOUSEHOLDER –We recommend you read pages 4 to 18.
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................................................................................................................... 16
Installation.................................................................................................................................. 19
Installation –Solar Collectors.................................................................................................. 34
System Assembly...................................................................................................................... 37
Connections –Plumbing .......................................................................................................... 48
Connections –Electrical........................................................................................................... 51
Multiple Installations................................................................................................................. 54
Commissioning.......................................................................................................................... 56
Draining The Solar Storage Tank............................................................................................. 59
Draining The Closed Circuit..................................................................................................... 60
Warranty..................................................................................................................................... 62

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®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 Rheem Australis or Titan solar collectors (RL series) and the 52H tank (indirect
system) is suitable for installation with Rheem S200 (52H series), Australis or Titan solar collectors
(RLX series).
The 52L and RL series systems do not have freeze protection. These systems are not 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 (refer to “Terms of the Rheem Warranty” on page 62).
The 52H and RLX 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 62).
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 and RL series are a direct solar hot water system and the 52H and
RLX series are an indirect solar hot water system with a heat exchanger in the solar storage tank.
52L, RL 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, RLX 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.
The solar water heater works on the simple scientific fact that hot
fluid rises. As the sun heats the water or closed circuit fluid in the
solar collectors, the increase in temperature causes the fluid to
rise through a copper pipe into the storage tank (52L, RL series)
or heat exchanger (52H, RLX 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.
Automatic safety controls are fitted to the water heater to provide safe and efficient operation.

ABOUT YOUR WATER HEATER
5
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 7.
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 Run Down” on page 7).
The booster heating unit is controlled by an electric thermostat. The thermostat 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.
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 21, a pressure limiting valve must be
fitted. The supply pressure should be greater than 350 kPa for true mains pressure operation to be achieved.
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. During periods high solar
radiation conditions and low hot water consumption, a system fitted
with an over temperature protection (OTP) system may heat the
water up to 85°C, whilst the water temperature could exceed 85°C
for a system without OTP.
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 7.
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.
maximum booster setting
maximum recommended
supply temperature to
bathrooms and ensuites
minimum booster setting

ABOUT YOUR WATER HEATER
6
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 water heater features a tradesperson adjustable thermostat. This requires a licensed tradesperson 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 have your electrician 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 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 power for the electrically operated components. The removal of the side
cover will expose 240 V wiring. It must only be removed by a qualified person.
Care should be taken not to 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 flow through the pipe work from the solar collectors to the solar storage tank.
Note: Any exposed pipe work or fittings in the solar circuit should be attended to and covered with insulation.
Phone Rheem Service or their nearest Accredited Service Agent to arrange for an inspection.
Should the water from a 52H or RLX series water heater appear blue or if blue closed circuit fluid is noticed
around 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.
SAFETY
This water heater is supplied with a thermostat, an over-temperature cut-out, 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 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.
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
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.
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.
TEMPERATURE RUN DOWN
Temperature run down is the reduction in water temperature as the hotter water at the top of the storage
cylinder transfers some of its heat to the cooler water in the lower section of the cylinder.
This effect is often perceived as heat loss, but is actually the redistribution of stored heat more evenly over
the entire contents of the storage tank. This heat is not lost to the system. This may make it necessary to use
the booster to raise the water in the top section of the cylinder back to an acceptable temperature.
Over-night temperature run down is most evident in the morning if the booster switch or time clock is left OFF
over-night. It is more prevalent the more hot water is used the night before and also in the cooler months.
Day time temperature run down is quite evident on days of lower solar radiation particularly during the cooler
months if the power to the booster heating element is not available, or the booster switch or time clock is left
OFF.
If higher temperature water is required, particularly in the morning, then use of the booster heating unit is
necessary to raise the temperature of the water in the top section of the cylinder. Refer to “Booster Control”
on page 7.
BOOSTER CONTROL
An isolating switch is installed in the electrical meter box for the 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 thermosiphon solar storage tank will be
90 litres (180 tank) or 150 litres (300 tank).
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.
If used with an extended Off-Peak (overnight and day) electricity supply, the timer switch should:
be operated by a continuous power supply on its own circuit from the switchboard with the booster
heating unit operated by the Off-Peak power supply. A double pole isolating switch is required to be
installed at the switchboard to simultaneously isolate both circuits.
or
be of a type which has an internal rechargeable battery to keep time when the power supply is not
available to the timer.

ABOUT YOUR WATER HEATER
8
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 the recommended continuous length of time for boosting,
and
for a period when power will be available for the booster heating unit to operate.
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 sufficient to 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.
RAIN WATER TANK
If the 52H or RLX series solar water heater is installed on a section of roof which is part of a rain water runoff
collection system, then it is recommended this section of roof and its gutter be isolated from the rain water
collection system. The gutter should be isolated to a width greater than the solar water heater and pipe work
and must have suitable drainage. This is to ensure in the event of a leak from the closed circuit, a rainwater
tank cannot be contaminated with closed circuit fluid.
The closed circuit fluid contains food grade additives (rust inhibitor and anti-freeze agent), is non-toxic and is
harmless to the environment. However, if it enters a rain water tank it can cause an unpleasant odour to
develop and result in the rain water tank having to be drained and cleaned.

ABOUT YOUR WATER HEATER
9
FREEZE PROTECTION
The 52H and RLX series solar water heaters are an indirect closed circuit solar hot water system with a heat
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 temperature of -8°C.
If lower temperatures are anticipated, a greater concentration of closed circuit fluid will be required.
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 62).
The 52L and RL series systems do 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 62).
PIPE WORK AND INSULATION
The solar hot and solar cold pipe work between the thermosiphon solar storage tank and the solar collectors
are supplied in the pipe 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 pipes must 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.
Note: Any exposed pipe work or fittings in the solar circuit should be attended to and covered with insulation.
Phone Rheem Service or their nearest Accredited Service Agent to arrange for an inspection.
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, however thicker insulation may be required to comply with the requirements of
AS/NZS 3500.4
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 corrosion protection to a metal roof against water runoff over the copper pipe, assist
in avoiding accidental contact with the solar pipe work as high temperature water or closed circuit fluid 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 temperature and pressure of the closed circuit
fluid generated by the solar collectors under certain conditions (refer to Warning on page 36).
The pipe work between the solar storage tank and in-series booster (if one is installed) MUST BE of copper
and fully insulated with a closed cell type insulation or equivalent (minimum thickness 13 mm).

ABOUT YOUR WATER HEATER
10
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 at the isolating switch to the solar storage tank.
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 at the isolating switch to the solar storage tank.
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 10. 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.
HOW DO I KNOW IF THE WATER HEATER IS INSTALLED CORRECTLY?
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 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 15.
HOW LONG WILL THE WATER HEATER LAST?
The water heater is supported by a manufacturer‟s warranty (refer to page 62). 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 7.

11
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 (if accessible). It is very important you
raise and lower the lever gently. Refer to “Temperature Pressure Relief Valve” on page 12.
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: 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 12.
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.
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 five year 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 fitted). If required, replace the valve.
Check the booster heating unit for excessive calcium build up or corrosion and replace if necessary.
Check the closed circuit fluid level (52H / RLX series).
Flush and bleed the solar collectors (52L / RL series)
Clean the collector glass.
Visually check the unit for any potential problems.
Inspect all connections.
Check the drain line from the safe tray (if one is installed) is not blocked.
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 the water by solar gain. Depending upon the power
supply connection to the booster heating unit, hot water may not be available until the next day.

REGULAR CARE
12
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 17).
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.
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.
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 13).
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.
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. If the collector glass becomes dirty, hose down or if the solar collectors
are accessible, wash the collector glass with water and a soft brush when the solar collectors are cool.
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 necessary to fit a guard to a collector. Stone Guards are available to provide a level of
protection to the collectors against vandalism or accidental damage. Refer to your local Solar Distributor for
details.
lift until water
flows from the
drain line –
lower gently
drain
line
water
heater

13
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 one water supply to another, e.g. a rainwater tank supply, bore water
supply, desalinated water supply, public reticulated water supply or water brought in from another supply,
then water chemistry information should be sought from the supplier or it should be tested to ensure the
water supply meets the requirements given in these guidelines for the 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 13.
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
14
SATURATION INDEX
The saturation index is used as a measure of the water‟s corrosive or scaling properties.
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 may be treated with a water softening device to reduce the saturation index of the
water.
Refer to the Saturation Index chart on page 14. Refer to the cold water connection detail on page 48 for the
position of the expansion control valve.
Contact Rheem Service or their nearest Accredited Service Agent if a replacement heating unit is required.
-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 - ELECTRIC BOOST
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
+0.4 +0.80
very corrosive very scaling
scaling
corrosive

WATER SUPPLIES
15
SUMMARY OF WATER CHEMISTRY ADVICE AFFECTING WARRANTY
The water heater and its components are not suitable for certain water chemistries. Those chemistries are
listed below. If the water heater is connected at any time to a water supply with the following water chemistry,
the Rheem warranty will not cover any resultant faults on the components listed below:
Water Chemistry
Component
Chloride > 250 mg/L
water heater cylinder and heat exchanger
pH < 6.0
water heater cylinder and heat exchanger
Saturation Index (SI) < -1.0
solar collector in a direct system
copper sheathed heating unit
Saturation Index (SI) > +0.4
(if an expansion control valve is not fitted)
water heater cylinder and heat exchanger
temperature pressure relief valve
Saturation Index (SI) > +0.8
solar collector in a direct system
standard watts density heating unit

16
SAVE A SERVICE CALL
Check the items below before making a service call. You will be charged for attending to any condition or
fault that is not related to manufacture or failure of a part.
NOT ENOUGH HOT WATER (OR NO HOT WATER)
This can occur with new installations and is normally related to some misunderstandings as to the use of the
booster heating unit.
Insufficient sunlight
Insufficient sunlight due to cloudy weather during hotter months or
low solar energy contribution in colder months may mean the
booster heating unit is required to boost more often.
Ensure the booster heating unit is being used as advised. Refer to
“Booster Control” on page 7.
Booster heating unit not operating
Inspect the isolating switch marked “HOT WATER” or “WATER
HEATER” at the switchboard and ensure it is turned “ON”.
Check the timer (if one is installed) and its settings to ensure power
is available to the booster heating unit.
Note: Check the electricity supply to which the unit is connected. If on an Off-Peak or time controlled
electricity supply remember heating hours are restricted.
Check the fuse marked “HOT WATER” or “WATER HEATER” at the switchboard.
Collectors shaded
If trees or other objects shade the solar collectors or if the glass is dirty, the effectiveness of the solar
collectors will be greatly reduced. Have the trees trimmed or the solar collectors relocated if the
obstruction is permanent or clean the collector glass (refer to “Collector Glass” on page 12).
Are you using more hot water than you think?
Is one outlet (especially the shower) using more hot water than you think?
Very often it is not realised the amount of hot water used, particularly when showering. Carefully review
the family‟s hot water usage. As you have installed an energy saving appliance, energy saving should
also be practised in the home. Adjust your water usage pattern to take advantage of maximum solar
gains.
Have your plumber install a flow control valve to each shower outlet to reduce water usage.
Temperature pressure relief valve running
Is the relief valve discharging too much water?
Refer to “Temperature Pressure Relief Valve Running” on page 17.
Thermostat setting
Ensure the thermostat setting is appropriate. You may choose to have your electrician adjust the
thermostat upwards to gain additional hot water capacity when boosting.
Refer to “Temperature Adjustment” on page 6.
Warning: Hotter water increases the risk of scald injury.
Water heater size
Do you have the correct size water heater for your requirements?
The sizing guides in the sales literature and on the Rheem website (www.rheem.com.au) suggest
average sizes that may be needed.

SAVE A SERVICE CALL
17
WATER NOT HOT ENOUGH
You may find that due to heavy hot water usage or low solar energy gain the water temperature may be
lower than normally expected. Ensure the booster is being used as advised. If a timer is installed, you will
need to carefully plan your use of the booster heating unit to boost the water temperature on such occasions.
Refer to “Booster Control” on page 7.
A lower water temperature may also be noticed in the morning when the booster heating unit has not been
energised overnight. This in particular may be experienced during periods of low solar energy gain and can
be caused by the transfer of heat energy overnight to the cold water in the lower portion of the solar storage
tank, or if there has been heavy hot water usage the previous night. Refer to “Temperature Run Down” on
page 7.
TEMPERATURE PRESSURE RELIEF VALVE RUNNING
Normal Operation
It is normal and desirable this valve allows a small quantity of
water to escape during the heating cycle. However, if it
discharges more than a bucket full of water in 24 hours,
there may be another problem.
Continuous dribble
Try gently raising the easing lever on the relief valve for a
few seconds (if accessible) (refer to “Temperature Pressure
Relief Valve” on page 12). This may dislodge a small particle
of foreign matter and clear the fault. Release the lever gently.
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.
Steady flows for long period (often at night)
This may indicate the mains water pressure sometimes rises above the designed pressure of the water
heater. Ask your installing plumber to fit a pressure limiting valve.
Warning: Never replace the relief valve with one of a higher pressure rating.
Heavy flows of hot water until the water heater is cold - then stops until water reheats
If this occurs when the water heater is being boosted by the electric booster heating unit, then the water
heater must be switched off at the isolating switch or switchboard. Phone Rheem Service or their
nearest Accredited Service Agent to arrange for an inspection.
This may also occur on a water heater without an over temperature protection (OTP) system during
periods of increased solar gain in the hotter months and particularly if there is a reduced level of hot
water consumption. It is most likely to happen during the daytime.
One of the functions of the temperature pressure relief valve is to relieve the tank of excess energy,
i.e. when water temperature increases to a high level. This higher temperature water is replaced with
incoming cold water to reduce the energy level inside of the tank. The valve will close when cooler water
surrounds the temperature probe of the valve. As this is a function of the temperature pressure relief
valve under these conditions, it is not necessary to make a service call.
EXPANSION CONTROL VALVE RUNNING
An expansion control valve fitted in the cold water line to the water heater (refer to page 48)may discharge a
small quantity of water instead of the temperature pressure relief valve on the water heater. The benefit is
that energy is conserved as the discharged water is cooler.

SAVE A SERVICE CALL
18
COLLECTOR GLASS
The Rheem warranty DOES NOT cover breakage of solar collector glass. Check your household insurance
policy covers collector glass breakage.
Warning: No attempt should be made to remove or replace broken collector glass.
The collector glass is not offered as a replacement part. Should the solar collector require replacement,
contact Rheem Service or their nearest Accredited Service Agent.
HIGHER THAN EXPECTED ELECTRICITY BILLS
With the installation of your new solar hot water system, maximum electrical energy savings can be achieved
with careful planning of hot water usage. Should you at any time feel your electricity account is higher than
expected, we suggest you check the following points:
Is the relief valve running excessively?
Refer to “Temperature Pressure Relief Valve Running” on page 17.
Is one outlet (especially the shower) using more hot water than
you think?
Refer to “Not Enough Hot Water” on page 16.
Is there a leaking hot water pipe, dripping hot water tap, etc?
Even a small leak will waste a surprising quantity of hot water and
energy. Replace faulty tap washers, and have your plumber rectify
any leaking pipe work.
Are you using the booster heating unit properly?
Refer to “Booster Control” on page 7.
Has there been an increase in hot water usage?
An increase in hot water usage may result in an increase in booster operation.
Has your water heating tariff rate been increased by your electricity retailer since your previous account?
ELECTRICITY TARIFFS
The electricity tariff to which your solar water heater is connected will play an important role in the overall
effectiveness of the system. It is important you are aware of this tariff to enable you to take full advantage of
the boosting period, i.e. Domestic / Continuous or Time of Use, Extended Off-Peak (overnight and day) or
extended time controlled, or Off-Peak (overnight) or time controlled.
IF YOU HAVE CHECKED ALL THE FOREGOING AND STILL BELIEVE YOU NEED ASSISTANCE,
PHONE RHEEM SERVICE OR THEIR NEAREST ACCREDITED SERVICE AGENT.

19
INSTALLATION
THIS WATER HEATER IS NOT SUITABLE FOR POOL HEATING.
SOLAR COLLECTORS
The 52L tank is suitable for installation with Rheem Australis or Titan solar collectors and the 52H tank is
suitable for installation with Rheem S200, Australis or Titan solar collectors.
In Australia, systems with Australis or S200
collectors are suitable for installation in all climate
zones.
In Australia for climate zones 1, 2, and 3 there is a
risk that systems with Titan collectors may over
perform. We recommend that in climate zones 1, 2,
and 3 Titan systems, with 2 or more collectors, only
be installed at orientations between 60° and 90°
from the equator.
In Australia in climate zone 4, systems with
selective surface Titan collectors provide optimum
performance compared with non selective surface
collectors, particularly in the months of lower solar
radiation.
IMPORTANT NOTES
Working on roofs is and should always be considered a hazardous activity, particularly early in the
morning, late in the evening, when the roof is wet or during and after periods of rain.
All work must be carried out in accordance with Local, State and Federal Occupational Safety, Health
and Welfare Regulations. In particular, the requirements for safety whilst manual lifting, working at
heights and on roofs.
Installers must be competently trained in:
Height Hazard Assessment
Working at Height Procedures
Assessment / Use / Wearing of correct height safety equipment (harnesses etc.)
All other relevant safety factors specific to the installation and maintenance work to be compliant
with suitable Occupational, Health and Safety Regulations / Codes.
All relevant permits shall be obtained from the regulatory authorities before commencing work to install
the solar hot water system.
All work carried out must be performed by appropriately qualified tradespeople or be suitably supervised
for trades assistant duties.
Every care must be taken to protect and warn occupants of the building and the public from personal
injury which may occur from falling tools, roof materials, fittings or any other hazards of a general nature.
Advise the occupants of any inconvenience which may occur due to disconnection of existing water and
electrical supplies.
The connection, attachment, integration or general association of other equipment or parts which either
directly or indirectly affect the operation or performance of this equipment could void the Rheem
warranty.
All packaging materials must be removed from the solar storage tank prior to its installation. Refer to the
warning on page 40 in relation to the removal of the solar collector packaging.

INSTALLATION
20
FREEZE PROTECTION
The 52L and RL series systems do not have freeze protection. These systems are 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 62).
The 52H and RLX series systems are 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 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 62).
The 52H and RLX series systems are supplied with closed circuit concentrate. During installation and
commissioning the closed circuit concentrate is blended with water in the appropriate proportion to achieve
the required frost protection. The amount of closed circuit concentrate supplied with this water heater
provides protection in frost prone areas to a temperature of -8°C. If a lower temperature protection is
required, additional closed circuit concentrate will be needed. The storage cylinder must be filled with water
before charging the closed circuit with closed circuit fluid. Refer to “Closed Circuit Fluid” on page 57.
INSTALLATION STANDARDS
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 Installers
Notice to Victorian Installers from the Victorian Plumbing Industry Commission if this solar water heater is
installed in a new Class 1 dwelling in the State of Victoria. The system model number is to be recorded on
the Certificate of Compliance. It is also a requirement to provide the householder with permanent
documentation recording the system model number exactly as it is shown in the „List of systems capable of
complying with the regulations‟ published by Sustainability Victoria (see www.sustainability.vic.gov.au). This
documentation may be in the form of an indelible label adhered to the solar storage tank, or other suitable
form placed in an accessible location, such as the meter box, for later inspection.
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.
If this water heater is to be used where an uninterrupted hot water supply is necessary for the application or
business, then there should be redundancy within the hot water system design. This should ensure the
continuity of hot water supply in the event that this water heater was to become inoperable for any reason.
We recommend you provide advice to the system owner about their needs and building backup redundancy
into the hot water supply system.
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 these installation instructions will not be applicable to the installation.
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.