Rheem Optima Technical Document

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

PATENTS
This water heater may be protected by one or more patents or registered designs
in the name of Rheem Australia Pty Ltd.
TRADEMARKS
® Registered trademark of Rheem Australia Pty Ltd.
TM Trademark of Rheem Australia Pty Ltd.
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.

CONTENTS
About Your Water Heater ............................................................. 4
Regular Care .................................................................................. 9
Water Supplies ........................................................................... 11
Save A Service Call ................................................................... 15
Installation .................................................................................. 18
Connections – Plumbing ........................................................... 25
Connections – Electrical ............................................................. 28
Commissioning .......................................................................... 31
Draining The Water Heater ....................................................... 34
Warranty ..................................................................................... 36
HOUSEHOLDER - We recommend you read pages 4 to 17.
The other pages are intended for the installer but may be of interest

4
ABOUT YOUR WATER HEATER
MODEL TYPE
The Rheem® water heater you have chosen is an Optima™ model.
The Optima model has a temperature adjusting knob on the lower front of
the water heater. Optima models are available with either a single heating unit
or with twin heating units. (refer to “Single Element Model” on page 7 and
“Twin Element Model” on page 7).
The water heater can be installed indoor or outdoor. Optima models have an
extended warranty (refer to the warranty on page 36).
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.
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 19, 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 water heater features an
adjustable thermostat, which allows
you to choose the most suitable
temperature for your hot water needs.
Refer to “Temperature Adjustment” on
page 5.
To meet the requirements of the
G12 Building Code the temperature of
the stored water must not be below 60°C.
maximum thermostat setting
Optima models
minimum thermostat setting
and minimum recommended
stored water temperature.
top heating unit thermostat
setting on a twin element
model (not adjustable)

ABOUT YOUR WATER HEATER
5
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 an Optima 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
An Optima water heater features a user adjustable
thermostat, which allows you to choose the most
suitable temperature for your hot water needs. To
adjust the temperature, push in the child resistant
knob and turn anticlockwise to decrease or
clockwise to increase the temperature setting. The
Optima has a minimum temperature setting of 60°C
and a maximum temperature setting of 75°C.

ABOUT YOUR WATER HEATER
6
WARNING
This water heater is only intended to be operated by persons who have the
experience or the knowledge and the capabilities to do so. This water heater is
not intended to be operated by persons with reduced physical, sensory or
mental capabilities i.e. the infirm, or by children. Children should be supervised
to ensure they do not interfere with the water heater.
This water heater uses 240 V AC power for the electrically operated
components. The removal of the front cover(s) will expose 240 V wiring. It must
only be removed by an authorised or qualified person.
Take care not to touch the power plug on a water heater fitted with a power
supply cord and plug with wet hands.
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 an authorised or
qualified person.
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 warranty can become void 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
SINGLE ELEMENT MODEL
This type of water heater has one heating
unit with its own thermostat. The heating
unit is at the base of the water heater.
Continuous electricity supply
This type of connection is suited to
where the storage capacity is less than
the normal daily usage.
Off-Peak electricity supply
This type of connection will only allow
heating to occur during set hours. A
volume of water sufficient for the day‟s
total use is heated and stored. This type
of heating will be more economical due
to reduced tariffs by the electricity
authority.
TWIN ELEMENT MODEL
This type of water heater has two heating units, each with its own thermostat.
One heating unit is at the base of the water heater and the other near the top.
Bottom heating unit
During normal operation this heating
unit supplies all the hot water.
Top heating unit (Booster)
This heating unit only operates during
periods of high demand to provide an
additional supply of heated water.
Electrical connection
The two heating units are wired for non-
simultaneous operation, so that only
one heating unit can operate at a time.
The bottom heating unit is usually
connected to an Off-Peak (overnight) or
time controlled electricity supply and the
top heating unit to a continuous supply.
Some electricity suppliers allow both
heating units to be metered at the Off-
Peak or controlled tariff.
NOTE: Power must be available to the top heating unit circuit at all times
for this water heater to operate as designed.

ABOUT YOUR WATER HEATER
8
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 isolating switch to the water heater.
Unplug the power supply cord from the power outlet (power supply cord
model only).
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.
Plug in the power supply cord at the power outlet (power supply cord model
only).
Switch on the electrical supply at the isolating switch to the water heater.
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.
HOW DO I KNOW IF THE WATER HEATER IS INSTALLED CORRECTLY?
Installation requirements are shown on pages 18 to 26. The water heater must
be installed by an authorised person and the installation must comply with
National Standards AS/NZS 3500.4, AS/NZS 3000 and all local codes and
regulatory authority requirements. The installation must conform with the
New Zealand Building Code.
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 cylinder and fittings. If
you are in a known harsh water area you must read page 11. If you are not
sure, have your water chemistry checked against the conditions described on
page 11.
HOW LONG WILL THE WATER HEATER LAST?
There are a number of factors that will affect the length of service the water
heater will provide. These include the water chemistry, the water pressure, the
water temperature (inlet and outlet) and the water usage pattern. However,
your water heater is supported by a comprehensive warranty (refer to page 36).

9
REGULAR CARE
TEMPERATURE PRESSURE RELIEF VALVE
This valve is near the top of the water
heater and is essential for its safe
operation. It is possible for the valve to
release a little water through the drain
line during each heating period. This
occurs as the water is heated and
expands by approximately 1/50 of its
volume.
Continuous leakage of water from the
valve and its drain line may indicate a
problem with the water heater (refer to
“Temperature Pressure Relief Valve
Running” on page 16).
Warning: Never block the outlet of
this valve or its drain line for any
reason.
Operate the easing lever on the
temperature pressure relief valve once
every six months. It is very important
you raise and lower the lever gently.
DANGER: Failure to do this may
result in the water heater cylinder
failing, or under certain circumstances,
exploding.
If water does not flow freely from the
drain line when the lever is lifted, then
the water heater should be checked by
a Rheem Service Centre.
The temperature pressure relief 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 (refer to “Water Supplies” on
page 11).
water
heater
drain
line
lift until water
flows from the
drain line –
lower gently

REGULAR CARE
10
TEMPERATURE LIMITING VALVE
The valve should be checked for performance every twelve months. This can
be performed by measuring the water temperature from a hot tap with a
thermometer. If the water is being delivered at a temperature exceeding 55°C,
phone a Rheem Service Centre.
The valve should be replaced at intervals not exceeding 5 years, or more
frequently in areas where there is a high incidence of water deposits (refer to
“Water Supplies” on page 11). Failure to do this may result in water at a
temperature up to 70°C being delivered at the hot tap, increasing the risk of
scald injury.
EXPANSION CONTROL VALVE
An expansion control valve must be 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.
GENERAL MAINTENANCE
The jacket of the water heater can be cleaned with a soft cloth and warm mild
soapy water on a 3 monthly interval in coastal areas. Under no circumstances
should abrasive materials or powders be used.