Rheem Eclipse 6C318500A Technical Document

This water heater must be installed and serviced by a qualified person.
Please leave this guide with a responsible officer.
Owner’s Guide
and
Installation Instructions
Rheem Eclipse®
Continuous Flow
Electric Water Heater

An electronic copy of these Owner’s Guide and Installation Instructions can be downloaded from rheem.com.au.
PATENTS
This water heater may be protected by one or more patents or registered designs in the name of Rheem Australia Pty
Ltd or Paloma Co., Ltd.
Rheem Australia Pty Ltd is the supplier of the Rheem range of continuous flow gas water heaters, manufactured by
Paloma Co., Ltd., a world leader in water heater technology and manufacture.
® Registered trademark of Rheem Australia Pty Ltd.
™ Trademark of Rheem Australia Pty Lt
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.
Warning: Upon completion of the installation and commissioning of the water heater, leave this guide
with a responsible officer or the householder.
RESPONSIBLE OFFICER, HOUSEHOLDER AND INSTALLER PLEASE NOTE
This Owner’s Guide and Installation Instructions is shared for the Australian and New Zealand markets.

3
CONTENTS
HOUSEHOLDER / RESPONSIBLE OFFICER
This booklet contains important information about your
new water heater, including terms of the Rheem warranty.
We recommend you read pages 7 to 17,
and the terms of the Rheem warranty on pages 4 to 6.
The other pages are intended for the installer but may be of interest.
Contents....................................................................................................................................... 3
Safety, Warnings, Installation Notes......................................................................................... 7
About Your Water Heater............................................................................................................ 9
Water Supplies........................................................................................................................... 14
Save A Service Call................................................................................................................... 16
Installation.................................................................................................................................. 18
Connections - Plumbing........................................................................................................... 21
Connections – Electrical........................................................................................................... 25
Commissioning.......................................................................................................................... 29
RHEEM AUSTRALIA PTY LTD, A.B.N. 21 098 823 511
www.rheem.com.au, www.rheem.co.nz
For Service Telephone 131 031 AUSTRALIA or 0800 657 335 NEW ZEALAND

4
RHEEM CONTINUOUS FLOW ELECTRIC WATER HEATER
WARRANTY – AUSTRALIA AND NEW ZEALAND ONLY
CONTINUOUS FLOW ELECTRIC WATER HEATER, 6C318500A, 6C318600A, 6C327500A, 6C327600A
MODELS 1. THE RHEEM WARRANTY – GENERAL
1.1 This warranty is given in Australia by Rheem Australia Pty Limited ABN 21 098 823 511 of 1 Alan Street,
Rydalmere New South Wales, and in New Zealand by Rheem New Zealand Limited of 475 Rosebank
Road Avondale Auckland 1026, the suppliers of Rheem continuous flow gas water heaters.
1.2 Rheem offer a trained and qualified national service network who will repair or replace components at
the address of the water heater subject to the terms of the Rheem warranty. Rheem Service, in addition
can provide preventative maintenance and advice on the operation of your water heater. The Rheem
ServicecontactnumberinAustralia is131031,withContact Centrepersonnelavailable24 hours,7 days
a week to take your call and if necessary to arrange a service call for during normal working hours
Monday to Friday (hours subject to change) or in New Zealand on 0800 657 335.
1.3 For details about this warranty, you can contact us in Australia on 131031 or by email at
[e-mail] (not for service bookings), or in New Zealand on 0800 657 335 or by
email at [e-mail] (not for service bookings).
1.4 The terms of this warranty and what is covered by it are set out in sections 2 and 3 and apply to water
heaters manufactured after 1st September 2018.
1.5 If a subsequent version of this warranty is published, the terms of that warranty and what is covered by
it will apply to water heaters manufactured after the date specified in the subsequent version.
2. TERMS OF THE RHEEM WARRANTY AND EXCLUSIONS TO IT
2.1 The decision of whether to repair or replace a faulty component is at Rheem’s sole discretion.
2.2 If you require a call out and we find that the fault is not covered by the Rheem warranty, you are
responsible for our standard call out charge. If you wish to have the relevant component repaired or
replaced by Rheem, that service will be at your cost.
2.3 Where a failed component or cylinder is replaced under this warranty, the balance of the original
warranty period will remain effective. The replacement does not carry a new Rheem warranty.
2.4 Where the water heater is installed outside the boundaries of a metropolitan area as defined by Rheem
or further than 25 km from either a regional Rheem branch office or an Accredited Rheem Service
Agent’s / Centre’s office, the cost of transport, insurance and travelling between the nearest branch
office or Rheem Accredited Service Agent’s / Centre’s office and the installed site shall be the owner’s
responsibility.
2.5 Where the water heater is installed in a position that does not allow safe or ready access, the cost of
that access, including the cost of additional materials handling and/or safety equipment, shall be the
owner’s responsibility. In other words, the cost of dismantling or removing cupboards, doors or walls
and the cost ofany special equipment to bring the water heater to floor or groundlevel or to a serviceable
position is not covered by this warranty.
2.6 Thiswarrantyonlyappliesto the originaland genuine Rheemwaterheaterin itsoriginalinstalledlocation
and any genuine Rheem replacement parts.
2.7 The Rheem warranty does not cover faults that are a result of:
a) Accidental damage to the water heater or any component (for example: (i) Acts of God such as
floods, storms, fires, lightning strikes and the like; and (ii) third party acts or omissions).
b) Misuse or abnormal use of the water heater.
c) Installation not in accordance with the Owner’s Guide and Installation Instructions or with relevant
statutory and local requirements in the State or Territory in which the water heater is installed.
d) Connection at any time to a water supply that does not comply with the water supply guidelines as
outlined in the Owner’s Guide and Installation Instructions.
e) Repairs, attempts to repair or modifications to the water heater by a person other than Rheem
Service or a Rheem Accredited Service Agent / Centre.

5
RHEEM CONTINUOUS FLOW ELECTRIC WATER HEATER
WARRANTY – AUSTRALIA AND NEW ZEALAND ONLY
CONTINUOUS FLOW ELECTRIC WATER HEATER, 6C318500A, 6C318600A, 6C327500A, 6C327600A
MODELS
f) Faulty plumbing or faulty power supply.
g) Failure to maintain the water heater in accordance with the Owner's Guide and Installation
Instructions.
h) Transport damage.
i) Fair wear and tear from adverse conditions (for example, corrosion).
j) Cosmetic defects.
k) Ice formation in the waterways of a water heater: where the electricity supply has been switched off
or has failed and the water heater has not been drained in accordance with the instructions; or due
to an ambient temperature below -20°C (including wind chill factor).
2.8 Subject to any statutory provisions to the contrary, this warranty excludes any and all claims for damage
to furniture, carpet, walls, foundations or any other consequential loss either directly or indirectly due to
leakage from the water heater, or due to leakage from fittings and/ or pipe work of metal, plastic or other
materials caused by water temperature, workmanship or other modes of failure.
2.9 If the water heater is not sized to supply the hot water demand in accordance with the guidelines in the
Rheem water heater literature, any resultant fault will not be covered by the Rheem warranty.
2.10 In New Zealand 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 water heater 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
All components when used in
a single-family residence
Years 1-5 Repair and/or
replacement of the faulty
component, free of charge, including labour.
All components when used in
other than a single-family
residence
Year 1

6
RHEEM CONTINUOUS FLOW ELECTRIC WATER HEATER
WARRANTY – AUSTRALIA AND NEW ZEALAND ONLY
CONTINUOUS FLOW ELECTRIC WATER HEATER, 6C318500A, 6C318600A, 6C327500A, 6C327600A
MODELS
4. ENTITLEMENT TO MAKE A CLAIM UNDER THIS WARRANTY
4.1 To be entitled to make a claim under this warranty you need to:
a) Be the owner of the water heater or have consent of the owner to act on their behalf.
b) Contact Rheem Service without undue delay after detection of the defect and, in any event, within
the applicable warranty period.
4.2 You are not entitled to make a claim under this warranty if your water heater:
a) Does not have its original serial numbers or rating labels.
b) Is not installed in Australia or 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 on 131031 in Australia or 0800 657 335 in New Zealand and provide owner’s
details, address of the water heater, a contact number and date of installation of the water heater
or if that’s unavailable, the date of manufacture and serial number (from the rating label on the water
heater).
b) Rheem will arrange for the water heater to be tested and assessed on-site.
c) If Rheem determines that you have a valid warranty claim, Rheem will repair or replace the water
heater in accordance with this warranty.
5.2 Any expenses incurred in the making of a claim under this warranty will be borne by you.
6. THE AUSTRALIAN CONSUMER LAW
6.1 In Australia, our goods come with guarantees that cannot be excluded under the Australian Consumer
Law. You are entitled to a replacement or refund for a major failure and for compensation for any other
reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if
the goods fail to be of acceptable quality and the failure does not amount to a major failure.
6.2 The Rheem warranty (set out above) is in addition to any rights and remedies that you may have under
the Australian Consumer Law.
7. THE CONSUMER GUARANTEES ACT 1993 (NEW ZEALAND)
7.1 In New Zealand, 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.
7.2 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).

7
SAFETY, WARNINGS, INSTALLATION NOTES
It is important you read the following safety and warnings information.
SAFETY AND WARNINGS
This water heater must be installed in compliance with the Plumbing Code of Australia (PCA).
Warning: – This water heater may deliver water at high temperature. Refer to the Plumbing Code of Australia,
local requirements and these installation instructions to determine if additional delivery temperature control is
required.
Warning: – For continuedsafety of this appliance, it must be installed, operated and maintained in accordance
with the manufacturer’s instructions.
Warning: Do not switch on the appliance if there is a possibility that the water in the heater is frozen.
•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 (including children) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge, unless they have been given
supervisionor instructionconcerninguseof the appliancebya personresponsiblefortheir safety. Children
should be supervised to ensure they do not interfere with the water heater.
•This appliance must be permanently connected to fixed wiring.
•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 Rheem Service or their nearest Accredited Service Agent to arrange for an
inspection.
•The water heater uses 415V- 3 phase 50Hz electrical power for operation of the control systems. The
removal of the front panel will expose 415V- 3 phase wiring. It must only be removed by a qualified person.
•The resistivity of the water supply must not be less than 800Ω·cm.
•This appliance must be earthed.
•This water heater is supplied with an over temperature cut-out, high pressure sensor and an emergency
cut-out switch. 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 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 or emergency cut-out operates, it must not be reset and the water heater
must be serviced by a qualified person.
•Servicing of the water heater must only be carried out by qualified personnel. Phone Rheem Service or
their nearest Accredited Service Agent / 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.

8
INSTALLATION NOTES
This water heater must be installed:
•by a qualified person,
•in accordance with the installation instructions,
•in compliance with the Plumbing Standard AS/NZS 3500.4,
This water heater is designed for indoor installation only.
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.
•in compliance with the Australian / New Zealand Wiring Rules AS/NZS 3000,
1. 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.
2. 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 in compliance with all local codes and regulatory authority requirements,
•In New Zealand, the installation must also conform to Clauses G11, G12 and H1 of the New Zealand
Building Code.
Installation and commissioning requirements and details for the installing plumber and licensed electrical
worker are contained on pages 18 to 29.
Mains pressure water supply
The water heater is designed to operate at mains pressure by connecting directly to the mains water supply.
The maximum mains water supply pressure for the water heater is 750 kPa. If the mains supply pressure in
your area exceeds 750 kPa, an approved pressure limiting valve that does not have non-return valve
characteristics (such as an RMC PSL series valve) must be installed.
A minimum water supply pressure of 150kPa is recommended to achieve the rated flow and performance of
the water heater. A turn on flow rate of 2.8 Lpm is required to initiate heating.
Mounting of the water heater
This water heater must be installed vertically upright with the water and power connections on the underside.
The back of the water heater can be either against a wall or supported by a frame. The water heater must be
well secured to the wall or frame using at least two screws (provided).
This water heater has an IP25 ingress protection rating. AS/NZS 3000 clause 6.2 allows this appliance to be
installed within zones 1 ,2 or 3 in a bathroom, kitchen or laundry. We recommend the appliance be limited to
zone 2 or 3.

9
ABOUT YOUR WATER HEATER
WATER HEATER APPLICATION
This water heater is designed for the purpose of heating potable water. Its use in an application other than this
may shorten its life.
MODEL TYPE
The Rheem Elcipse®continuous flow electric water heater model you have chosen is for indoor installation
only. It has an IP25 ingress protection rating.
The water heater has a maximum preset outlet temperature setting of:
Model Name Model Number
Max
temperature
1. Rheem Eclipse® 18kW 50⁰C Water Heater* 6C318500A 50°C
2. Rheem Eclipse® 18kW 60⁰C Water Heater 6C318600A 60°C
3. Rheem Eclipse® 27kW 50⁰C Water Heater* 6C327500A 50°C
4. Rheem Eclipse® 27kW 60⁰C Water Heater 6C327600A 60°C
*This appliance delivers water not exceeding 50oC in accordance with AS 3498.
WATER HEATER OPERATION
The water heater operates automatically, heating water as it passes through the
water heater. When a hot tap is opened, the unit energises the nickel chrome
heating elements (with 99% heating efficiency) to provide immediate heating of the
water. The electric elements modulate according to the demand of hot water. The
water heater starts heating instantaneously when a hot tap is opened at a flow rate
greater than 2.8L/min.
Automatic safety controls are fitted to the water heater to provide safe and efficient
operation.
USER TOUCH SCREEN
To save energy, the touchscreen will cease illuminating after a period of 5 minutes
with no activation or water usage.
To wake the screen, press any button located at the bottom of the screenas shown
in the image adjacent.
The display screen shows set point temperature, flowrate and volume of water
used information and working status with indicator lights.
•Orange light bar at top of screen indicates the water heater is operating
and temperature setting is below 42⁰C.
•Red light bar at top of screen indicates the water heater is operating and
temperature setting is 42⁰C or higher.
When water is being drawn, the flow rate indicator (L/MIN) will display the actual flow rate. The water volume
counter (L) will display the accumulated water consumed. The water volume indicator will clear automatically
after 5 minutes of no water use or user interaction or with a power cycle.

10
PRESET MEMORY & BATH OPTION
There are three pre-set output temperature memory buttons on the 60⁰C and 50⁰C models. M1 and M2 are
factory set at typical showering temperatures for quick change of set points. The Bath symbol is factory
set at a lower temperature for children or elderly people. Memory presets can be adjusted and saved by the
user to best meet temperature preferences.
•M1 is factory set at 38⁰C
•M2 is factory set at 41⁰C
•Bath is factory set at 38⁰C
TEMPERATURE ADJUSTMENT
Set Point Setting
Press ‘˄’to increase or ‘˅’to decrease set point in 0.5⁰C change for each press. Press and hold‘˄’to increase
or ‘˅’to decrease for 5⁰C change increments in 60⁰C and 50⁰C models between the maximum temperature
and 30⁰C.
M1 and M2
To enter M1/M2 press the appropriate button. The preset temperature will be displayed and water will be
delivered at this temperature.
To adjust M1/M2 temperature, simply pressing ‘˄’ or ‘˅’ will exit out of M1/M2 mode and allow free
temperature adjustment.
To save a new M1/M2 temperature to memory, press and hold M1 or M2 button as appropriate for 3 sec. The
temperature display will blink to indicate you are in a temperature setting mode and the water volume counter
will blink with either 1 or 2 to indicate which memory you are altering. Then adjust temperature set point by
pressing ‘˄’to increase or ‘˅’to decrease and then press M1 or M2 button as appropriate once to finalise the
value. If no button is pressed for 1 minute the system will exit memory mode and any settings will not be saved.
Bath Mode
To enter Bath Mode, press the bath icon button . The preset temperature will be displayed, and water will
be delivered at this temperature. The water flow rate indicator will alternately blink between the water flow rate
and “bA” to indicate you are in Bath Mode.
To adjust Bath Mode temperature, press ‘˄’ to increase or ‘˅’ to decrease between 32⁰C and 41⁰C.
To exit Bath Mode,press and hold the bath icon for 3 sec. The water flow rate indicator will cease blinking
to acknowledge exiting Bath Mode and allow free temperature adjustment.
Note: Bath mode temperature can be adjusted as required but cannot be saved. Bath mode will default to the
factory preset temperature each time it is entered.

11
HOW HOT SHOULD THE WATER BE?
The maximum preset outlet temperature setting is model
dependant. The water heater delivers heated water to the preset
outlet temperature setting. The factory preset outlet temperature
setting is:
•6C318500A Model 50⁰C
•6C318600A Model 60⁰C
•6C327500A Model 50⁰C
•6C327600A Model 60⁰C
Warnings
This water heater is only intended to be operated by personswho
have the experience or the knowledge and the capabilities to do
so. This water heater is not intended to be operated by persons
(including children) with reduced physical, sensory or mental
capabilities, or lack of experience and knowledge, unless they
have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety. Children
should be supervised to ensure they do not interfere with the
water heater.
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.
In New Zealand a water heater with a maximum set temperature of 60°C is permissible, however it is the
responsibility of the installer to set the maximum delivery temperature to not exceed 55°C at the first tap used
for ablution purposes.
60⁰C model water heaters can be connected to a temperature limiting device to allow 2 temperature zones to
be serviced.
TEMPERATURE LIMITATION AND OFFSET
The water heater can be trade adjusted to either increase the set point to allow for heat losses within the hot
water line to the first tap to the maximum temperature allowable (50 degree limited model) or to limit the
maximum delivery temperature (all models). Ask Rheem Service or your plumber about trade temperature
adjustments.
PRECAUTIONS
The water heater mustbe maintained in accordance with the Owner’s Guide and Installation Instructions. Refer
to “General Maintenance” on page 11 and “Service Every Twelve Months”on page 12.
If this water heater is to be used where an uninterrupted hot water supply is necessary for your application or
businessyoushould ensurethatyou haveback-up redundancy within thehotwater systemdesign.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.
GENERAL MAINTENANCE
General maintenance can be performed by the dwelling occupant. It is recommended general maintenance
be conducted every six (6) months or more regularly as required.
Switch off the electrical supply at the isolation switch to the water heater prior to performing general
maintenance. This will prevent the water heater from operating while you clean or spray around the water
heater. Switch on the electrical supply at the isolation switch to the water heater when finished performing the
general maintenance.
NZ – maximum recommended
supply temperature to bathrooms,
ensuites and public areas
AU – maximum recommended
supply temperature to bathrooms,
ensuites and public areas

12
The general maintenance includes:
Use a soft wet cloth to wipe smoothly, do not use petrol or other solvents. Under no circumstances should
abrasive materials or powders be used.
•After finishing, use dry cloth to wipe again and keep the water heater dry.
•Inspect around the water heater for infestations of insects, such as ants. Insects encroaching into or
nesting in the water heater can interfere with the operation of the water heater and also damage
components. The area around the water heater can be sprayed with insecticide to rid the area of insects.
Warning: Do not spray insecticide near the water heater while it is operating. Propellants in many
insect sprays contain hydrocarbons which are flammable. Gases from aerosol sprays may also become
corrosive.
If necessary, to rid the area of insects:
Ensure the electrical supply at the isolation switch to the water heater has been switched off.
Spray the affected area, taking care not to spray onto the surface of the water heater.
Wait a few minutes to allow any aerosol gases to dissipate before switching on the electrical
supply at the isolation switch to the water heater.
SERVICE EVERY TWELVE MONTHS
For safe and efficient operation, it is recommended a service be conducted on the water heater every
twelve (12) months.
Warning: Servicing of a water heater must only be carried out by qualified personnel. Phone Rheem
Service or their nearest Accredited Service Agent / Centre.
Note: The service and routine replacement of any components, if required, 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 service includes the following actions:
•Check and clean the line strainer, and flow regulator
•Visually check the unit for any potential problems.
•Inspect all connections.
TO TURN OFF THE WATER HEATER
If it is necessary to turn off the water heater:
•Switch off the electrical supply at the isolation switch to the water heater.
•Close the cold water isolation valve at the inlet to the water heater.
TO TURN ON THE WATER HEATER
Warning: power must not be activated until the water heater has been filled with water and all lines purged of
air. Failure due to air in the system is not covered by the Rheem warranty.
•Ensure the electricity supply to the water heater is TURNED OFF
•Make sure cold inlet and hot outlet are connected to the water heater according to the installation
instructions.
•Open the hot taps (don’t forget the shower).
•Open the cold water isolation valve fully at the inlet to the water heater.
Air will be forced out of the taps.
•Close each tap as water flows freely from it.
•Switch on the electrical supply at the isolation switch to the water heater.
The water heater will operate automatically when you open a hot tap.

13
DRAINING THE WATER HEATER
•Switch off the electrical supply at the isolation switch to the water heater.
•Close the cold water isolation valve.
•Open a hot tap (preferably the shower outlet). When water stops flowing, close the hot tap.
•Unscrew the inlet and outlet connections. Water will drain from the water heater.
GOING ON HOLIDAYS
If you are going on holidays, it is not necessary to turn the water heater off. If it is necessary to turn off the
water heater, refer to “To Turn Off The Water Heater” on page 12.
VICTORIAN CUSTOMERS
Notice to Victorian Customers from the Victorian Building Authority. This water heater must be installed by a
licensed person as required by the Victorian Building Act 1993.
Only a licensed person will give you a Compliance Certificate, showing that the work complies with all the
relevant Standards. Only a licensed person will have insurance protecting their workmanship for 6 years. Make
sure you use a licensed person to install this water heater and ask for your Compliance Certificate.
DOES THE WATER CHEMISTRY AFFECT THE WATER HEATER?
The water heater is suitable for most public water supplies, however some water chemistries may have
detrimental effects on the water heater, its components, fittings and operation. Refer to “Water Supplies” on
page 14.
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 page 14.
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 11.

14
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 the water heater.
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 the heating element and other components and cause
them to fail.
Where the chloride level exceeds 250 mg / L the Rheem warranty does not apply to the water heater.
pH is a measure of whether the water is alkaline or acid. In an acidic or very alkaline water supply, the water
can attack the heating element and other components and other parts and cause them to fail.
Where the pH is less than 6.0 or greater than 9.5, the Rheem warranty does not apply to the water heater.
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 this water heater.
Refer to the pH and Chloride chart on page 14.
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 60⁰C.
WITHIN WARRANTY
SPECIFICATION
5.0 6.0 7.0 8.0 9.0
350
300
250
200
150
100
50
CHLORIDE -mg/L
pH & CHLORIDE
WATER HEATERS (stainless steel cylinder)
acidic alkaline
pH
no warranty applies to a:
-stainless steel water heater
cylinder
0
no warranty applies to a:
-stainless steel water heater cylinder
no warranty applies to a:
-stainless steel water heater
cylinder
10.09.5
No warranty applies to:
continuous flow electric
water heater for water
chemistry related failures
CONTINUOUS FLOW ELECTRIC WATER HEATER
no warranty applies to:
continuous flow electric water heater
for water chemistry related failures
No warranty applies to:
continuous flow electric
water heater for water
chemistry related failures

15
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 copper
components.
In a scaling water supply calcium carbonate is deposited out of the water onto any hot metallic surface.
Where the saturation index exceeds +0.80, the Rheem warranty does not apply to the heating element.
Water that 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 15.
RESISTIVITY, TOTAL DISSOLVED SOLIDS AND CONDUCTIVITY
The resistivity of the water must be greater than 800Ohm.cm for the water heater to operate correctly.
Resistivity lower than this may cause residual current devices (RCD) to trip.
There is a correlation between resistivity, Total Dissolved Solids (TDS) and conductivity.
Water chemistry is usually provided for TDS in units of mg/Litre or conductivity expressed in units of µS/cm.
TDS is approximately 0.7 x conductivity.
The water chemistry is suitable for this water heater, in terms of resistivity, if the TDS is ≤875 mg/L or the
conductivity is <1250 µS/cm.
Refer to the Resistivity, TDS and Conductivity chart on page 15
-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 - STAINLESS STEEL
WITHIN WARRANTY
SPECIFICATION
SATURATION INDEX
(calculated @ 80°C water temperature)
no warranty applies to a:
-standard watts density heating unit -stainless steel cylinder
+0.4 +0.80
very corrosive very scaling
scaling
corrosive
SATURATION INDEX (SI)
CONTINUOUS FLOW ELECTRIC WATER HEATER
No warranty applies to:
copper components
WITHIN WARRANTY
SPECIFICATION
No warranty applies to:
the heating element
RESISTIVITY, TOTAL DISSOLVED SOLIDS (TDS) AND
CONDUCTIVITY CONTINUOUS FLOW ELECTRIC WATER HEATER
RESISTIVITY Ω.cm
600 700 800 900 1000 1100
1167 1000 875 780 700 636
1667 1430 1250 1110 1000 909
TDS mg/L
CONDUCTIVITY µS/cm
WITHIN WARRANTY
SPECIFICATION
NO WARRANTY
APPLIES FOR
FAILURES RELATED
TO RESISTIVITY AND
TDS

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,
which is not related to manufacture or failure of a part (refer to “Terms of the Rheem Warranty” on page 4).
NO DISPLAY ON THE WATER HEATER
•Is the water heater turned on?
Press any button located at the bottom on the front of the water heater or turn on a hot water tap.
•Is the water heater switched on at the power supply?
•Is power available in the premises?
Try using another electrical appliance.
COLD WATER FROM THE HOT TAP
•Is the temperature on the screen showing correct values?
If not, adjust temperature by pressing ‘˄’ or ‘˅’buttons.
•Close the hot tap, wait 10 seconds and open the hot tap again.
•Is the hot tap open enough?
The water heater will not turn on if the flow rate is less than
2.8 L / min.
•Is the water heater switched on at the power supply?
•Is power available in the premises?
Try using another electrical appliance.
•Has the water line been purged of air after installation? Refer to a
plumber.
•Is the filter blocked? Refer to a plumber.
WATER IS TOO HOT OR NOT HOT ENOUGH
•Is the preset outlet temperature of the water heater higher than required?
•Has the water heater temperature been adjusted to the desired value of delivery temperature?
•A 50 degree limited water heater can have its delivery temperature adjusted by a tradesperson to account
for temperature losses in the hot pipes or to limit the maximum delivery temperature. In New Zealand, a
60 degree model can have its maximum delivery temperature limited by a tradesperson in accordance
with local regulations. Contact Rheem or a plumber.
•Do you have the correct size water heater for your requirements? Refer to a plumber.
NOT ENOUGH WATER FLOW
•The water heater is fitted with a line strainer to prevent the system from blockages due to debris. Have
Rheem Service or a plumber inspect the line strainer.
•Is more water being used than the water heater can heat adequately? A flow regulator is supplied with the
water heater. Rheem Service or a plumber can remove the flow regulator, but this may affect the delivery
temperature if more water than can be heated is used.
•Is the water pressure adequate to deliver the desired flow rate? The table below indicates the flow rate vs
supply pressure with and without the flow regulator fitted.
Dynamic Supply Pressure (kPa)
150
200
250
300
350
400
450
500
Capacity
Maximum Flow Rate with Flow Regulator Fitted (L/min)
18kW
6.4 – 6.9
6.6 – 7.8
6.6 – 8.5
6.8 – 7.4
6.9 – 7.5
7.0 – 7.5
7.2 – 7.6
7.4 – 7.7
27kW
NA
NA
NA
NA
NA
NA
NA
NA
Maximum Flow Rate without Flow Regulator Fitted (L/min)*
18kW
7.8
9.5
11.0
12.0
13.3
14.5
15.7
16.5
27kW
6.7
8.5
9.6
10.5
11.5
12.6
13.5
14.5
*Rheem Service or a plumber can remove the flow regulator, but this may affect the delivery temperature if
more water than can be heated is used.

SAVE A SERVICE CALL
17
TEMPERATURE FLUCTUATES
Too many taps in use at the same time may cause either a reduction in flow rate per tap or a decrease in the
hot temperature from the taps if the flow regulator is removed.
•Are there several hot taps open, or are appliances such as a dishwasher or washing machine in use at
the same time?
•Check the flow of hot water from each tap to see if one or more outlets are using more water than you
think.
•The supply of consistent hot water temperature is dependent on the size of the water heater, the
geographic location and the season. Have a plumber install a flow control valve to each shower outlet,
basin and sink to reduce water usage. The water heater is supplied with a factory fitted flow regulator.
This may have been removed during installation. Contact Rheem Service or a plumber to fit an approved
flow regulator. This will provide consistent hot water delivery temperature but at a limited maximum flow
rate.
•The following table indicates the flow rate required, and the maximum flow rate capable (without flow
regulator), from each model water heater at various cold water inlet temperatures to provide hot water at
40⁰C to a 9L/min limited shower rose.
Cold Water Temperature ⁰C
5
10
15
20
25
Model
Flow Rate Required / Flow Rate Capable without Flow Regulator
(L/min)
6C318600A
5.7 / 4.7*
5.4 / 5.1*
5.0 / 5.7
4.5 / 6.5
3.9 / 7.3
6C318500A
7.0 / 5.7*
6.8 / 6.5*
6.4 / 7.4
6.0 / 8.6
5.4 / 10.3
6C327600A
5.7 / 7.0
5.4 / 7.7
5.0 / 8.6
4.5 / 9.7
+
3.9 / 11.1
+
6C327500A
7.0 / 8.6
6.8 / 9.7
6.4 / 11.1
6.0 / 12.9+
5.4 / 15.5++
*Not recommended for cold climate areas where the cold water supply temperature drops below 10⁰C in winter.
+ Can supply up to 2 showers simultaneously.
++ Can supply up to 2 showers simultaneously. Theoretical capacity based on kW input rate.
Note: refer to the table on page 16 for the maximum flow rate capable for various dynamic supply pressures.
NO WATER FROM THE HOT TAP
No flow of water from the hot tap may indicate a restriction in or failure of the cold water supply to the water
heater.
•Check for water flow at other taps and that the cold water isolation valve is fully open.
•Have Rheem Service or a plumber check the filter for blockages.
ERROR CODE
The water heater provides a diagnostic error code in the event of an interruption to its operation. The error
code is displayed in the temperature display window after 1 minute if no buttons are pressed.
•E1 – inlet thermistor disconnected. The heater will cease to heat water.
•E2 - outlet thermistor disconnected. The heater will cease to heat water.
•E3 – Outlet temperature over 75⁰C. The heater will turn off until the outlet thermistor registers a
temperature less than 40⁰C. The heater will shut down if the error is recorded 5 times, indicating a serious
problem.
•E4 – No temperature rise detected across the inlet and outlet. The heater will continue to function. E4
could be detected because the cold water supply was high (for example cold water pipe running in roof
heated by the sun on a hot day). E4 will automatically reset once a temperature difference is detected.
If the error code persists, take note of the code and turn off the hot tap. Phone Rheem Service or their nearest
Accredited Service Agent / Centre to arrange for inspection.
IF YOU HAVE CHECKED ALL THE FOREGOING AND STILL BELIEVE YOU NEED ASSISTANCE, PHONE
RHEEM SERVICE OR THEIR NEAREST ACCREDITED SERVICE AGENT / CENTRE.

18
INSTALLATION
THIS WATER HEATER IS FOR INDOOR INSTALLATION ONLY.
THIS WATER HEATER IS NOT SUITABLE FOR POOL HEATING.
WATER HEATER APPLICATION
This water heater is designed for the purpose of heating potable water. Its use in an application other than this
may shorten its life.
INSTALLATION STANDARDS
The water heater must be installed:
•by a qualified person, and
•in accordance with the installation instructions, and
•in compliance with the Plumbing Code of Australia (PCA), Standards AS/NZS 3500.4 and AS/NZS 3000,
and all local codes and regulatory authority requirements.
In New Zealand the installation must conform to Clauses G11, G12 and H1 of the New Zealand Building Code.
All packaging materials must be removed from the water heater prior to its installation.
PIPE SIZES
The pipe sizing for hot water supply systems should be carried out by persons competent to do so, choosing
the most suitable pipe size to ensure adequate flow for each individual application. Reference to the technical
specifications of the water heater and local regulatory authority requirements must be made.
To reduce pressure drop, the cold water line to the water heater should be the same size or larger than the
hot water line from the water heater.
Notes
•It is not recommended to install this water heater with a low-pressure water supply. The table below
indicates the flow rate vs supply pressure with and without the flow regulator fitted.
•This water heater is not suitable for connection to bore water or spring water unless a water treatment
device is fitted.
Dynamic Supply Pressure (kPa)
150
200
250
300
350
400
450
500
Capacity
Maximum Flow Rate with Flow Regulator Fitted (L/min)
18kW
6.4 – 6.9
6.6 – 7.8
6.6 – 8.5
6.8 – 7.4
6.9 – 7.5
7.0 – 7.5
7.2 – 7.6
7.4 – 7.7
27kW
NA
NA
NA
NA
NA
NA
NA
NA
Maximum Flow Rate without Flow Regulator Fitted (L/min)*
18kW
7.8
9.5
11.0
12.0
13.3
14.5
15.7
16.5
27kW
6.7
8.5
9.6
10.5
11.5
12.6
13.5
14.5
*Removing the flow regulator will allow increased flow, but this may affect the delivery temperature if more
water than can be heated is used.

19
The following table indicates the flow rate required,and the maximumflow rate capable (withoutflow regulator),
from each model water heater at various cold water inlet temperatures to provide hot water at 40⁰C to a 9L/min
limited shower rose.
Cold Water Temperature ⁰C
5
10
15
20
25
Model Flow Rate Required / Flow Rate Capable (L/min)
6C318600A
5.7 / 4.7*
5.4 / 5.1*
5.0 / 5.7
4.5 / 6.5
3.9 / 7.3
6C318500A
7.0 / 5.7*
6.8 / 6.5*
6.4 / 7.4
6.0 / 8.6
5.4 / 10.3
6C327600A
5.7 / 7.0
5.4 / 7.7
5.0 / 8.6
4.5 / 9.7+
3.9 / 11.1+
6C327500A
7.0 / 8.6
6.8 / 9.7
6.4 / 11.1
6.0 / 12.9
+
5.4 / 15.5
++
*Not recommended for cold climate areas where the cold water supply temperature drops below 10⁰C in winter.
+ Can supply up to 2 showers simultaneously.
++ Can supply up to 2 showers simultaneously. Theoretical capacity based on kW input rate.
STEP 1: SELECT WATER HEATER LOCATION
The water heater is suitable for indoor installation only and should be installed close to the most frequently
used outlet and its position chosen with safety and service in mind.
Clearance must be allowed for servicing of the water heater. The water heater must be accessible without the
use of a ladder or scaffold. Make sure the entire front panel can be removed for service. You must be able to
read the information on the rating plate. Remember you may have to take the entire water heater out later for
servicing.
This water heater has an IP25 ingress protection rating. AS/NZS 3000 clause 6.2 allows this appliance to be
installed within zones 1 ,2 or 3 in a bathroom, kitchen or laundry. We recommend the appliance be limited to
zone 2 or 3.
We do not recommend installing the water heater within a roof space. Regulations require isolating all power
to a premises before entering a roof space which will render servicing or troubleshooting the unit impossible.
Warranty will be void if a water heater needs to be removed for servicing.
STEP 2: SECURE WATER HEATER TO THE WALL OR FRAME
This water heater must be installed vertically upright with the water and power connections on the underside.
The back of the water heater can be either against a wall or supported by a frame. The water heater must be
well secured to the wall or frame using the screws (provided).
a) Remove the front cover by first removing one screw located under the bottom. The screw is covered
by a sticky tab.
b) Carefully disconnect the display cable on the side as shown in Figure 1 on page 20.
c) Remove the grey cover at the bottom of the heater by removing two screws as marked in Figure 2on
page 20 to access the inlet/outlet and electrical connections.

INSTALLATION
THIS WATER HEATER IS FOR INDOOR INSTALLATION ONLY.
THIS WATER HEATER IS NOT SUITABLE FOR POOL HEATING.
WATER HEATER APPLICATION
This water heater is designed for the purpose of heating potable water. Its use in an application other than this
may shorten its life.
INSTALLATION STANDARDS
The water heater must be installed:
•by a qualified person, and
•in accordance with the installation instructions, and
•in compliance with the Plumbing Code of Australia (PCA), Standards AS/NZS 3500.4 and AS/NZS 3000,
and all local codes and regulatory authority requirements.
In New Zealand the installation must conform to Clauses G11, G12 and H1 of the New Zealand Building Code.
All packaging materials must be removed from the water heater prior to its installation.
PIPE SIZES
The pipe sizing for hot water supply systems should be carried out by persons competent to do so, choosing
the most suitable pipe size to ensure adequate flow for each individual application. Reference to the technical
specifications of the water heater and local regulatory authority requirements must be made.
To reduce pressure drop, the cold water line to the water heater should be the same size or larger than the
hot water line from the water heater.
20
Figure 1: Removing Display Cable Figure 2: Removing Grey Cover
d) Determine if connection of the plumbing and electricals will be concealed through the back of the unit
or through the bottom of the unit. Refer to Figure 4 on page 22 and Figure 7 on page 23. If plumbing
connections have been roughed in, determine the position of the heater on the wall to allow fitment in
accordance with the desired plumbing connection method.
e) Secure the water heater to the wall using the screws provided.
Note: Use the screws (provided) only if they are suitable for the wall or frame type. The screws must be
capable of bearing the full weight of the water heater so it may not work loose nor impose any load on the
water pipe work connected to the water heater.
Display Cable