Rheem 31202519V Technical Document

This water heater must be installed and serviced by a qualified person.
Please leave this guide with the householder.
Owner’s Guide
and
Installation Instructions
Electric Domestic
Water Heater
Model 31202519V

An electronic copy of these Owner’s Guide and Installation Instructions
can be downloaded from rheem.co.nz.
PATENTS
This water heater may be protected by one or more patents or registered designs
in the name of Rheem Australia Pty Ltd or Rheem New Zealand Limited.
TRADEMARKS
® Registered trademark of Rheem Australia Pty Ltd or Rheem New Zealand Limited.
TM Trademark of Rheem Australia Pty Ltd or Rheem New Zealand Limited.
Note: Every care has been taken to ensure the accuracy in preparation of this
publication. No liability can be accepted for any consequences,
which may arise as a result of its application.
RHEEM NEW ZEALAND LIMITED
www.rheem.co.nz
For Service Telephone [phone] NEW ZEALAND

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 23,
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..........................................................12
Maintenance Requirements ......................................................15
Water Supplies...........................................................................17
Save A Service Call ...................................................................21
Installation..................................................................................24
Connections –Plumbing ..........................................................32
Connections –Electrical...........................................................36
Commissioning..........................................................................38
Draining The Water Heater .......................................................39

4
RHEEM ELECTRIC DOMESTIC MAINS PRESSURE
WATER HEATER WARRANTY –NEW ZEALAND ONLY
ELECTRIC WATER HEATERS 312025 MODEL
In addition to your legal right, in New Zealand Rheem New Zealand Limited
makes the following promise to the owner. We will repair or, if necessary, replace
a defective unit or part of it, which has failed due to faulty manufacture on the
following terms and conditions:
1. THE RHEEM WARRANTY –GENERAL
1.1 This warranty is given in respect of sales in New Zealand by Rheem New
Zealand Limited of 475 Rosebank Road Avondale Auckland 1026.
1.2 Rheem offer a trained and qualified national service network who will repair or
replace components at the address of the unit subject to the terms of the
Rheem warranty in New Zealand –contact your Rheem Service Centre on
0800 657 335.
1.3 For details about this warranty, you can contact us at [email protected] (not
for service bookings) or phone your Rheem Service Centre on 0800 657 335.
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 from 1st November 2019.
1.5 If a subsequent version of thiswarranty 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 Rheem may reject a claim under this warranty in its sole discretion if:
a) You do not arrange for a major service to be conducted on your water
heater in the fifth year after installation, in accordance with Rheem’s
recommendation in the Owner’s Guide and Installation Instructions; and
b) The fault giving rise to the warranty claim would have been detected and
rectified during that major service.
2.2 The decision of whether to repair or replace a faulty component is at Rheem
New Zealand Limited’s sole discretion.
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 unit is installed outside the boundaries of a metropolitan area,
defined by Rheem as further than 25 km from a Rheem Service Centre, the
cost of transport, insurance and travelling between the Rheem Service Centre
and the installed site shall be the owner’s responsibility.

RHEEM ELECTRIC DOMESTIC MAINS PRESSURE
WATER HEATER WARRANTY –NEW ZEALAND ONLY
5
ELECTRIC WATER HEATERS 312025 MODEL
2.5 Where the unit 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, walls, roofs or
trap doors and the cost of any special equipment to bring the unit 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 unit in its original
installed location and anygenuine Rheem replacement parts. It does not cover
any plumbing, gas fitting or electrical parts supplied by the installer, that are
not an integral part of the unit, e.g. pipe-work, pressure limiting valve, stop
valves, non-return valves, electrical switches, pumps and fuses.
2.7 The Rheem warranty does not cover faults that are a result of:
a) Accidental damage to the unit or any component, for example Acts of God
such as floods, storms, fires, lightning strikes and the like and Third party
acts or omissions.
b) Misuse or abnormal use of the unit.
c) Installation or use not in accordance with the Owner’s Guide and
Installation Instructions, New Zealand Building Code requirements or with
relevant statutory and local requirements including failure to install a
properly drained safe tray where required by the owners guide and
installations.
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, or poor water quality outside the limits specified in the owners
guide and installation instructions.
e) Repairs, attempts to repair or modifications to the unit by a person other
than Rheem Service or a Rheem Accredited Service Technician.
f) Faulty plumbing or faulty power supply.
g) Failure to maintain the unit 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.
2.8 If you require a call out and we find that the fault is not covered by the Rheem
warranty, you are responsible for Rheem Service Centre call out costs. If you
wish to have the relevant component repaired or replaced by Rheem that
service will be at your cost.
2.9 Rheem may reject a claim under this warranty in its sole discretion if a third
party solar diverter is connected to the water heater.

RHEEM ELECTRIC DOMESTIC MAINS PRESSURE
WATER HEATER WARRANTY –NEW ZEALAND ONLY
6
ELECTRIC WATER HEATERS 312025 MODEL
2.10 Subject to any statutory provisions to the contrary, this warranty excludes any
and all claims however arising including under contract or tort for damage to
furniture, carpet, walls, foundations or any other consequential loss or
incidental expenses either directly or indirectly due to leakage from Rheem
unit, 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.
2.11 This warranty excludes to the extent permissible all implied warranties set out
in the Sale of Goods Act 1908 (New Zealand) and all guarantees set out in the
Consumers Guarantees Act 1993 (New Zealand) to the extent that the goods
are acquired for the purpose of resupply in trade consumption in the course of
a process of production or manufacture or repairing or treating in trade other
goods or fixtures on land.
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 unit if it fails to operate
in accordance with its specifications as follows:
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
312025 model
All components
Year 1
Repair and/or replacement of
the faulty component, free of
charge, including labour.
The cylinder
(if the water heater is
installed in a single-family
domestic dwelling)
Years 2 to 5
Repair and / or replacement
of the cylinder, free of charge,
including labour.
Years 6 to 10
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.

RHEEM ELECTRIC DOMESTIC MAINS PRESSURE
WATER HEATER WARRANTY –NEW ZEALAND ONLY
7
ELECTRIC WATER HEATERS 312025 MODEL
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 unit or have consent of the owner to act on their behalf.
b) Contact Rheem New Zealand Limited Service Department without undue
delay after detection of the defect and, in any event, within the applicable
warranty period.
c) Return the faulty component or unit as directed by the Rheem New
Zealand Limited Service Department.
4.2 You are not entitled to make a claim under this warranty if your unit:
a) Does not have its original serial numbers or rating labels.
b) Is not installed in New Zealand.
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 New Zealand on 0800 657 335 and provide the owner’s
details, address of the unit, a contact number and date of installation of the
unit or if that’s unavailable, the date of manufacture and serial number
(from the rating label on the unit).
b) A Rheem Service Centre will arrange for the unit to be tested and
assessed on-site.
c) If Rheem determines that you have a valid warranty claim, Rheem will
repair or replace the unit 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 CONSUMER GUARANTEES ACT 1993 (NEW ZEALAND)
6.1 Our goods come with guarantees that cannot be excluded under the Consumer
Guarantees Act 1993 (New Zealand). If the goods fail to comply with the
applicable guarantees set out under the Consumer Guarantees Act 1993 (New
Zealand) being the guarantee as to acceptable quality, the guarantee as to
correspondence with description or the guarantee as to repair and parts, or if
the goods fail to comply with any express guarantee given by Rheem, then you
are entitled to a replacement or refund and for compensation for any other
reasonably foreseeable loss or damage.
6.2 The Rheem warranty (set out above) is in addition to any rights and remedies
that you may have under the Consumer Guarantees Act 1993 (New Zealand).

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 water heater is damaged, it must be replaced
by a qualified person in order to avoid a hazard. Phone your Rheem Service
Centre to arrange for an inspection.
•This water heater uses 230 V a.c. power for the electrically operated
components. The removal of the front cover will expose 230 V a.c. wiring. It
must only be removed by a qualified person.
•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 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.
•The water heater will operate until a water temperature of 60°C to 70°C is
reached, depending upon the thermostat setting.
Refer to “How Hot Should The Water Be?” on page 12 and “Temperature
Adjustment” on page 13.
•The lever on the temperature pressure relief valve and expansion control
valve (if fitted) 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 9 and “Minor Maintenance Every Six
Months” on page 16.
•For continued safety of this water heater it must be installed, operated and
maintained in accordance with the Owner’s Guide and Installation
Instructions.

SAFETY, WARNINGS, INSTALLATION NOTES
9
•Servicing of a water heater must only be carried out by qualified personnel.
Phone your Rheem Service Centre.
•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.
RELIEF VALVES
Temperature Pressure Relief Valve
This water heater incorporates a
temperature pressure relief valve located
near the top of the water heater. 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 heating period. 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
It is mandatory an expansion control valve is fitted to the cold water line to the
water heater to comply with Clause G12 of the New Zealand Building Code,
unless the water heater is installed as a push through installation.
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 22.
Warning: Never block the outlet of either valve or their drain lines for any
reason. A relief valve drain must 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.

SAFETY, WARNINGS, INSTALLATION NOTES
10
Operate the easing lever on the temperature
pressure relief valve and expansion control
valve 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 16.
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 water heater cylinder failing, or under certain
circumstances, exploding.
If water does not flow freely from the drain line when the lever is lifted, then the
water heater must be checked. Phone your Rheem Service Centre 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 17.
INSTALLATION NOTES
This water heater must be installed:
•by a qualified person,
•in accordance with the installation instructions,
•to conform to Clauses G12 and H1 of the New Zealand Building Code,
•in compliance with the Plumbing Standard AS/NZS 3500.4,
▪This water heater is suitable for either indoor or 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 used for connection to the water heater, where
permitted by AS/NZS 3500.4.
lift until water
flows from the
drain line –
lower gently
drain
line

SAFETY, WARNINGS, INSTALLATION NOTES
11
•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 70°C under normal 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 24 to 38.
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 1000 kPa. If an expansion control valve has been installed on
the cold water line to the water heater, this should have a pressure rating of
850 kPa.
The maximum mains water supply pressure for the water heater is 800 kPa if an
expansion control valve is not installed, or 680 kPa if an expansion control valve
is installed. If the mains supply pressure in your area exceeds these values, a
pressure limiting valve must be installed.
The supply pressure should be greater than 350 kPa for true mains pressure
operation to be achieved.

12
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
The Rheem®312025 model water heater
you have chosen has a single heating unit
and is suitable for connection to a
continuous power supply. The water heater
is suitable for either indoor or outdoor
installation.
Water is stored in a vitreous enamel lined
steel cylinder and heated by the electric
immersion heating unit. The thermostat
controls the temperature. Automatic safety
controls are fitted to the water heater to
provide safe and efficient operation.
HOW HOT SHOULD THE WATER BE?
The water heater features a tradesperson
adjustable thermostat, which allows you to
choose the most suitable temperature for
your hot water needs. Refer to
“Temperature Adjustment” on page 13.
To meet the requirements of the New
Zealand Building Code the temperature of
the stored water must not be below 60°C.
HOTTER WATER INCREASES THE RISK OF SCALD INJURY
This water heater can deliver hot water at temperatures up to 70°C depending
upon the thermostat setting, sufficiently hot to cause severe scalding. Water at
these temperatures may have been plumbed to fixtures where water hotter than
55°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.
minimum thermostat
setting and minimum
recommended stored
water temperature
maximum thermostat
setting 312025 model
maximum recommended
supply temperature to
bathrooms and ensuites

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 a Rheem 312 series water heater is installed. This will keep
the water temperature below 55°C at the bathroom and ensuite. The risk of scald
injury will be reduced and still allow hotter water to the kitchen and laundry.
THERMOSTAT
The thermostat automatically controls the electricity supply to the heating unit so
a constant temperature is maintained. The thermostat and its protective over
temperature cut out is mounted inside the front cover of the water heater. There
is no need to switch the water heater off when it is not in use, except when you
are on an extended holiday. The thermostat is fully automatic and power is only
used when heating is required.
TEMPERATURE ADJUSTMENT
A Rheem 312025 model 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. The
minimum temperature setting is 60°C.
We advise you to have a licensed electrical worker adjust the thermostat to the
lowest temperature setting that meets your needs, especially if there are young
children or elderly people in your home. Refer to “Hotter Water Increases The
Risk of Scald Injury” on page 12.
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 safe tray must also meet the
requirements of Clause G12 of the New Zealand Building Code. AS/NZS 3500.4
and the NZBC also have particular requirements when a safe tray must be
installed.
The water heater must be maintained in accordance with the Owner’s Guide and
Installation Instructions. Refer to “Maintenance Requirements”on page 15 and
to “Anode Inspection and Replacement” on page 18.
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 a plumber or
specifier about your needs and building back-up redundancy into your hot water
supply system.

ABOUT YOUR WATER HEATER
14
TO TURN OFF THE WATER HEATER
If you plan to be away from home for only a few nights, we suggest you leave
the water heater switched on.
If it is necessary to turn off the water heater:
•Switch off the electrical supply at the water heater isolating switch on the
switchboard or at the isolating switch at the water heater (if installed).
•Close the cold water isolation valve at the inlet to the water heater.
TO TURN ON THE WATER HEATER
•Open the cold water isolation valve fully on the cold water line to the water
heater.
•Switch on the electrical supply at the water heater isolating switch on the
switchboard and at the isolating switch at the water heater (if installed).
GOING ON HOLIDAY?
If you plan to be away from home for one or two nights, we suggest you leave
the water heater switched on. However, if you plan to stay away more than a few
nights, conserve energy by switching the water heater off at either the
switchboard or isolating switch (if one is installed).
Note: When the electrical supply is switched back on, the water heater will take
some time to reheat the water.
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 17.
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 17 to 20.
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.

15
MAINTENANCE REQUIREMENTS
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 qualified
personnel. Phone your Rheem Service Centre.
Note: The major service and routine replacement of any components, such as
the anode and relief valve(s), are not included in the Rheem warranty. A charge
will be made for this work. Only genuine replacement parts should be used on
this water heater.
The major service includes the following actions:
•Replace the temperature pressure relief valve.
•Inspect and flush the expansion control valve (if fitted). If required, replace
the valve.
•Inspect and if required, replace the anode.
If the anode is not replaced, it should be replaced within five (5) years of this
service (refer to “Anode Inspection and Replacement” on page 18).
•Check the electric heating unit for excessive calcium build-up or corrosion
and replace if necessary.
•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 water heater may need to be drained during this service. After the
completion of the service, the water heater will take some time to reheat the
water.

MAINTENANCE REQUIREMENTS
16
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:
•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 9.
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.
•Operate the easing lever on the expansion control valve (if fitted). It is very
important the lever is raised and lowered gently. Refer to “Relief Valves”
on page 9.
•Check the drain line from the safe tray (if one is installed) is not blocked.

17
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 temperature pressure relief valve and a heating unit.
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.
ANODE
The vitreous enamel lined cylinder of the 312025 water heater is supplied with a
black colour coded anode and is only covered by the Rheem warranty when the
total dissolved solids (TDS) content in the water is from 40 mg/L to 600 mg/L.
The changing of an anode must be carried out by a qualified person.
Note: Some water analysis reports may state the conductivity of the water rather
than the level of total dissolved solids. Conductivity, measured in microsiemens
per centimetre (µS / cm), is directly proportional to the TDS content of the water.
TDS, in mg / L, is approximately 70% of the conductivity in µS / cm.

WATER SUPPLIES
18
ANODE INSPECTION AND REPLACEMENT
The anode installed in your water heater will slowly dissipate whilst protecting
the cylinder. The life of the cylinder may be extended by replacing the anode.
For water supplies which are either softened or desalinated, or where the water
supply may alternate between a water tank and a reticulated public supply or
another supply, or where there is a variable supply (e.g. from a bore or public
reticulated supply from various water sources), the anode must be inspected
(and replaced if there is any sign of depletion) within five (5) years of its
installation, and within every three (3) years thereafter.
For all water supplies, if the anode is not replaced during a major service (refer
to “Major Service Every Five Years” on page 15) then the maximum time after
installation when the anode should be replaced for this water heater is
ten (10) years.
CAUTION
If the water supply has a TDS greater than 600 mg/L, there is the possibility the
anode may become overactive and hydrogen gas could accumulate in the top of
the water heater during long periods of no use.
If, under these conditions, the water heater has not been used for two or more
weeks the following procedure should be carried out before using any electrical
appliances (automatic washing machines and dishwashers) which are
connected to the hot water supply.
The hydrogen, which is highly flammable, should be vented safely by opening a
hot tap and allowing the water to flow. There should be no smoking or naked
flame near the tap whilst it is turned on. Any hydrogen gas will be dissipated.
This is indicated by an unusual spurting of the water from the tap. Once the water
runs freely, any hydrogen in the system will have been released.

WATER SUPPLIES
19
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. A
corrosion resistant heating unit must be used for the Rheem warranty to apply to
the 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.
Where the saturation index exceeds +0.80, the Rheem warranty does not apply
to a standard watts density heating unit. A low watts density heating unit must be
used for the Rheem warranty to apply to the heating unit.
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 19. Refer to the cold water
connection detail on page 32 for the position of the expansion control valve.
Contact your Rheem Service Centre if a replacement heating unit is required.
+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
SATURATION INDEX (SI)
ELECTRIC WATER HEATERS
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
no warranty applies to a:
-standard watts density heating unit
very corrosive very scaling
scaling
corrosive

WATER SUPPLIES
20
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
Total Dissolved Solids (TDS) > 600 mg/L
(black colour coded anode installed)
water heater cylinder
Total Dissolved Solids (TDS) < 40 mg/L
(black colour coded anode installed)
water heater cylinder
Saturation Index (SI) < -1.0
copper sheathed heating unit
Saturation Index (SI) > +0.4
(if expansion control valve is not fitted)
water heater cylinder
temperature pressure relief valve
Saturation Index (SI) > +0.8
standard watts density heating unit