Rheem 862 27 Series Operating instructions

This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
Rheem Australia Pty Ltd ABN 21 098 823 511
27 Litre External/Internal
Electronic Gas Continuous Flow Water Heater
TM049
First Issued: Dec 09
Revision: AL
Issued: April 2019
Solahart
Edwards
Everhot
Vulcan
Rheem
10143272
362027
274X27
244X27
862X27
10143273
372027
276X27
864X27
10143274
374X27
866X27
10143275
872X27
874X27
876X27

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
2
CONTENTS
INTRODUCTION .................................................................................................................4
SAFETY WARNING.............................................................................................................4
Live Testing......................................................................................................................4
Touch Voltage Testing .....................................................................................................5
In-Service Testing ............................................................................................................6
WATER HEATER MODEL IDENTIFICATION.....................................................................7
SPECIFICATIONS...............................................................................................................9
WIRING DIAGRAM............................................................................................................10
PRODUCT CHANGES ......................................................................................................11
PRESET TEMPERATURE ADJUSTMENT .......................................................................14
SEQUENCE OF OPERATION...........................................................................................16
COMPONENTS AND THEIR FUNCTION .........................................................................18
IN-SERIES GAS BOOSTING ............................................................................................19
TEMPERING VALVES.......................................................................................................20
REMOTE TEMPERATURE CONTROLLERS....................................................................21
Bath Fill Operation..........................................................................................................26
EZ-LINK™SYSTEM..........................................................................................................28
MAINTENANCE INFORMATION.......................................................................................30
RESETTING ERROR CODES...........................................................................................32
OPERATIONAL FLOW CHARTS ......................................................................................33
ERROR CODES................................................................................................................37
DIAGNOSTIC TEST POINTS............................................................................................39
THERMISTOR RESISTANCE CHART..............................................................................40
FAULT FINDING................................................................................................................40
Fault Diagnosis Sequence .............................................................................................41
Power Supply Fault-Finding...........................................................................................42
No Error Code Fault Finding ..........................................................................................44
Error Code 11.................................................................................................................46
Error Code 12.................................................................................................................50
Error Code 14.................................................................................................................51
Error Code 15.................................................................................................................51
Error Code 16.................................................................................................................52
Error Code 24.................................................................................................................53
Error Code 29.................................................................................................................53
Error Code 31, 32, 33 & 34 ............................................................................................54

CONTENTS
TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
3
Error Code 35.................................................................................................................54
Error Code 51.................................................................................................................55
Error Code 52.................................................................................................................56
Error Code 61.................................................................................................................56
Error Code 65.................................................................................................................60
Error Code 66.................................................................................................................60
Error Code 71.................................................................................................................61
Error Code 72.................................................................................................................61
Error Code 76.................................................................................................................62
Error Code 79.................................................................................................................62
Error Code 80.................................................................................................................63
Error Code 82.................................................................................................................63
Error Code 90.................................................................................................................63
Error Code 99 / Warning Code 10..................................................................................64
EziSET®Fault-Finding.......................................................................................................65
BURNER GAS PRESSURE CHECK & ADJUSTMENT.....................................................67
COMPONENT REPLACEMENT PROCEDURES .............................................................68
FLUING REQUIREMENTS FOR INTERNAL MODELS.....................................................79
DOCUMENT REVISION HISTORY...................................................................................83

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
4
INTRODUCTION
The information provided in these service instructions is based on the water heater being
installed in accordance with AS/NZS 5601 and the Installation Instructions provided with
each water heater.
Contact Rheem Technical Support on 1300 712 863 should you require any further technical
advice regarding a 27L Continuous Flow water heater.
SAFETY WARNING
The purpose of this service manual is to provide sufficient information to allow a person with
the skills as required by the Regulatory Authorities to carry out effective repairs to a
continuous flow gas water heater in the minimum of time.
Safety precautions or areas where extra care should be observed when conducting tests
outlined in this service manual are indicated by print in bold italics and/or a warning symbol.
Take care to observe the recommended procedure.
Live Testing
A number of test procedures detailed within this service instruction
require ‘live’ testing to be conducted.
All State and Territory Authorities stipulate requirements that must be met
before working live i.e. conducting a risk assessment and/or preparing a
safe work method statement and wearing appropriate PPE.
It is the responsibility of the service person to be aware of and comply
with the requirements of the State or Territory where the water heater is
installed before working ‘live’.
An RCD shall be installed between the power point and 3-pin cord of the
water heater to reduce the risk of electric shock.
Isolate power before conducting the indicated test.
Hot surface or liquid. Personal Protective Clothing (PPE) shall be worn to
reduce the risk of scalding.
General warning symbol. Observe the instructions accompanying the
symbol.
If the supply cord is damaged, it must be replaced by the manufacturer or
its service agent or a similarly qualified person in order to avoid a hazard.
When conducting repairs to a gas appliance the gas train including
injector sizes must not be altered or modified in any way.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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5
Touch Voltage Testing
Under certain fault conditions it is possible for the
metal jacket of a water heater to become live.
The electrical fault may be an internal appliance
issue or an issue with the building supply wiring
(see diagram 1 opposite).
To check for a shock hazard in a suspect
installation a Touch Voltage Test must be
applied using the following equipment:
1. A high impedance multimeter with an
input impedance greater than 5 mega-
ohm.
2. A 2kΩresistor box fitted with contact
terminals.
3. A long trailing lead for connection to
the premises earth electrode.
Note: The 2kΩresistor is used to simulate
the body resistance of a typical person.
Diagram 2
Procedure:
Personal Protective Equipment (electrical insulating gloves) should be
worn when conducting this procedure to reduce the risk ofelectric shock.
1. Connect the resistance box between the metal casing of the appliance and the main
Earth electrode (Spike) using the long trailing lead (as shown in diagram 2).
2. Connect the multimeter (set on the AC volts scale) to the resistor box terminals and
record the reading.
3. If the reading is higher than 50VAC (Dry) or 25VAC (Wet) then there is a fault either
within the electrical installation or with the appliance.
4. To confirm the earthing of the water heater;
Electrically isolate the appliance from the electrical circuit.
Conduct an earth continuity test to AS/NZS 3760 (pay particular attention to the
cordset earth on plug in water heaters).
If the earth path of the appliance is intact, the problem is with the household wiring.
Diagram 1

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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In-Service Testing
It is a requirement of AS/NZS 3760 that an in-service test be performed when re-instating
an appliance to service.
Following any repairs to the water heater ensure that both an earth continuity test and
insulation test are carried out prior to completing service call as follows:
Wear Personal Protective Equipment when conducting these procedures to
reduce the risk of electric shock. Refer to Rheem safety procedure on electrical
testing.
Procedure 1: Check “Continuity” of the earth conductor.
1. Isolate power to the water heater by switching off at power point and unplugging
appliance 3 pin plug from power point.
2. Set multimeter to x1 resistance scale.
3. Measure between the Earth pin on the 3 pin plug and the heater jacket, a reading of ≤
0.5Ω should be obtained. If a reading greater than 0.5Ω is returned check the earth
connection at the water heater, if ok replace the cord.
Procedure 2: Insulation resistance of the water heater Active Circuit (reading not to
be below 1MΩ).
4. Connect megger leads to the Active and Earth pins of the 3 pin plug.
5. Operate megger. A reading above 1MΩshould be obtained.
6. If a reading below 1MΩis indicated, all component parts will need to be individuallytested
to locate the fault.
Procedure 3: Insulation resistance of the water heater Neutral Circuit. (Reading not to
be below 1MΩ).
7. Connect megger leads to the Neutral and Earth pins of the 3 pin plug.
8. Operate megger. A reading above 1MΩshould be obtained.
9. If a reading below 1MΩis indicated, all component parts will need to be individually tested
to locate the fault.
10.Plug 3 pin plug back into power point and switch on power point. Note: If continuing
with any diagnostic procedures do not perform this step.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
7
WATER HEATER MODEL IDENTIFICATION
Rheem/Vulcan/Everhot/Edwards
The model number is designed to convey detailed information about the water heater to
which it is attached.
87
4
0
27
N
F
/J
Brand
86 - Rheem Internal
87 - Rheem External
24 - Vulcan External
27 - Everhot External
36 - Edwards Internal
37 - Edwards External
Max Temperature
2 - 82ºC (60ºC factory set)
4 - 75ºC (60ºC factory set)
6 - 48ºC (48ºC factory set)
Star Rating
0 - 5 Star
6 - 6 Star
Capacity
27 - 27L/min @ 25 ºC rise
Gas Type
N –Natural
P - Propane
F - Frost protection fitted
Colour
J - Joey Grey
No letter - Refer below
Casing colour variations: Rheem/Edwards/Solahart - Antique White, Everhot - Joey Grey
Solahart Model Identification
Natural Gas
Propane
Solahart Gas Ext CF 60º 27L 5*
10143272
10143273
Solahart Gas Ext CF 60º 27L 6*
10143274
10143275
The model number, serial number and date of manufacture should be quoted in all correspondence.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
8
Model Options
The following model variants are available in the 27L CF range:
External Models:
Rheem
5 Star
6 Star
Rheem Gas CF 60º 27l/m Nat/Pro Ext
874027NF / PF
874627NF / PF
Rheem Gas CF 50º 27l/m Nat/Pro Ext
876027NF / PF
876627NF / PF
Rheem Gas CF 70º 27l/m Nat/Pro Ext
873027NF / PF
873627NF / PF
Rheem Gas CF 82º 27l/m Nat/Pro Ext
872027NF / PF
872627NF / PF
Vulcan
5 Star
6 Star
Vulcan Gas CF 60ºC 27l/m Nat/Pro Ext Site Int
244027NF/J / PF/J
244627NF/J / PF/J
Everhot
5 Star
6 Star
Everhot Gas CF 60ºC 27l/m Nat/Pro Ext
274027NF / PF
274627NF / PF
Everhot Gas CF 50ºC 27l/m Nat/Pro Ext
276027NF / PF
276627NF / PF
Solahart
5 Star
6 Star
Solahart Gas CF 60ºC 27l/m Nat/Pro Ext
10143272 / 73
10143274 / 75
Edwards
5 Star
6 Star
Edwards Gas CF 82ºC 27L/M Nat/Pro Ext
372027NF / PF
-
Edwards Gas CF 60ºC 27l/m Nat/Pro Ext
374027NF/J / PF/J
374627NF/J / PF/J
Internal Models:
Rheem
5 Star
6 Star
Rheem Gas CF 50º 27l/m Nat/Pro Int
866027NF / PF
866627NF / PF
Rheem Gas CF 60º 27l/m Nat/Pro Int
864027NF / PF
864627NF / PF
Rheem Gas CF 82º 27l/m Nat/Pro Int
862027NF / PF
862627NF / PF
Edwards
5 Star
6 Star
Edwards Gas CF 82ºC 27L/M Nat/Pro Int
362027NF / PF
-

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
9
SPECIFICATIONS
Model
27 NAT
27 PROP
Gas Input (MJ/hr)
205
205
Output (kW)
461
46.52
461
46.52
Installation
Indoor
Wall Mounting –can be flued horizontally or vertically.
Outdoor
Wall Mounting
Mass (kg)
24
Min Water Pressure (kPa)
140
Max Water Pressure (kPa)
1000
Min Water Flow (L/M)
2.0 (+0.5/-0.25)
Max Flow Rate @ 25°C Rise (L/M)
27
Max Flow Rate @ 40°C Rise (L/M)
16.51
16.72
Gas/Water Connections
R¾/20
Flue connection (mm)
(indoor models only)
Concentric
76.2 x 127
Max Flue Length
(indoor models only)
9 metres with 3 bends
Injector Orifice (qty x dia mm)
16 x 2.05
16 x 1.25
Burner Test Point
Pressure (kPa)
Indoor
Min
0.165
0.252
Max
0.900
1.3251
1.5502
Outdoor
Min
0.193
0.277
Max
0.905
1.4301
1.5402
Min Inlet Gas Pressure (kPa)
1.13
2.75
Max Inlet Gas Pressure (kPa)
3.5
Relief Valve Setting (kPa)
1750
Electrical
Rating
240 VAC/50Hz, 3 Amps
Fuse
2 x 3A Fuse (line voltage), 5A fuse on power supply PCB
Safety Devices
Over Heat Limiter for Heat Exchanger
Heat Exchanger Thermistor (Boiling Point Safety)
Freeze Protection
-20°C (Without Wind-Chill Factor) with power applied
Controllers (optional)
Kitchen Controller (K) or Deluxe Kitchen Controller (K)
Bath Controller (B1) or Deluxe Bath Controller (B1)
Bath Controller (B2) or Deluxe Bath Controller (B2)
EziSET®Kit (876 models only)
Burner test point pressure varies by model. Model type can be determined by referring to model number:
15 star model (4th digit of model number is 0, eg: 874027NF)
26 star model (4th digit of model number is 6, eg: 874627NF)

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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10
WIRING DIAGRAM
A wiring diagram is also located on the inside of the front cover panel.
POWER SUPPLY PCB
CONTROL PCB
TRANSFORMER
E
GY
7
8 9
10
11
12
1
2
3
4
5
6
GY
Y
BK R
FUSE
5A
1 2 3 4
BL
BR
A
B
12
GR R
1 3 2 5
6 4
C
BL BK
R
R
D
123
BL BR
HGY
G
F
1 2 3
4 5
6 7 8
1
2 3 4
IGNITER
IG
GND
BK
R
W
G Y
BR
3A
FUSE
BL BR
BRBL
BK W
W
FOR DIRECT VENT MODEL ONLY
PROTECTION
FROST
THERMOSTAT
BKW
W W ANTI-FROST HEATER
GND
1
Y
J
2 3 4 5 6
O R
BL
WR
BK
W
Y
BL
MODEL ONLY FOR DIRECT VENT
FM
FAN MOTOR
2 1I
R
GR
K
BK RYBR G W
123456 87
R
BK
BK
R
BL
4 3 2
1
7 6
5
P
Y
W
1
2 3 4
USUALLY
DISCONNECTED
BL
O
W
BR
R
BK
4 3 2
1
8 7 6
5
N
O9
Y
G
M
5
6 7 8
1
2 3 4
G
Y
BK
R
BR
W
O
BL
Q
BR
Y
9
5
6 7 8
1
2 3 4
GY
BL
BK
W
R
G
O
4 3 2
1 5
R
1
2 3
S
BR
BK
R
GAS TYPE CONNECTOR
FLOW WATER SENSOR
W
W
2
1
TLIMITER
OVERHEAT
W
1
UFLAME ROD
1
2 3
V
BL BL
BATH REMOTE CONTROL 2 CONTROL 1 REMOTE BATH KITCHEN REMOTE CONTROL
DISPLAY
LED
LED1
2 1
345
BKW
G R
Z
O
Y
Y
BL
BR GY
1234
240VAC
BK BL
R
R
X
3 1 25
4 6
W
1
5 6 7 8
432
Y W
BLRBK
GAS INLET SOLENOID VALVE 0 VALVE 1 SOLENOID SOLENOID VALVE 2 VALVE 3 SOLENOID
SW1 SW2 SW3
DIP1
1234
ON
OFF OFF
ON
4321
DIP2
WATER BY-PASS
CONTROL MOTOR LIMITER MOTOR
RBK GOWBR
BLYYBL BRWO
G
BK R
MOTOR
LIMITER CONTROL MOTOR
WATER VOLUME
THERMISTOR AMBIENT AIR WATER INLET THERMISTOR THERMISTOR HEAT EXCHANGER THERMISTOR HOT WATER
PGFR VALVE
PSV
-
+
BK
BK
BK

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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11
PRODUCT CHANGES
EziSET®- Smartphone Remote Control
EziSET®enables remote control of a CF water heater via a smartphone where the hot water
temperature set point and bath fill features can be controlled by the user through an App
installed on their own personal smartphone. Additionally, any applicable fault codes and
service contact details will be displayed on the App in the event of a heater fault.
EziSET®is not provided as standard with the CF heater, it is an optional extra that is
available to purchase in kit form that is to be retro-fitted to a new or existing installation.
Available from February 2019 using part number 052310 the kit is suitable for use with 50oC
models only (876027 / 876627 / 866027 / 866627 models).
The kit is required to be installed by a qualified technician; it
includes a PCB (refer A) that is to be fitted inside the water
heater and a PLT plug (Power Line Telecommunication) that
is to be connected to a GPO and wireless router in the home
(wireless router is not supplied however any home with an
existing Wi-Fi network will have one).
The householder is responsible for the download of the free
EziSET®App to their own compatible smartphone. Must have
a minimum operating system of IOS 8.1 (iPhone 5 or later;
excluding iPhone 5C) or Android 4.0 or later (Windows phone
is not compatible).
Up to 10 devices can simultaneously communicate with an EziSET®enabled heater
however only one user at a time can have priority control and alter heater settings.
The conventional hard-wired remote temperature controllers will continue to be available for
use where a home Wi-Fi network or a compatible mobile device are not available.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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12
Water Body & PCB Modification
Domestic models (874/876/864/866) manufactured from January 2018 and commercial
models (872/862) manufactured from February 2018 are fitted with a revised water body
and PCB.
The revised water body features a new flow turbine design and a material change to the
water body retaining ring. The PCB has been modified to suit this new water body assembly.
The revised water body can be identified by a black plug on the flow sensor wiring loom
(refer to fig 1) and the revised PCB can be identified by a black socket for the water body
flow sensor wiring plug (refer to fig 2).
Fig 1
Fig 2
Water Body Field Service Replacements –862/872 Series Commercial Models:
The revised water body, part number 41-18374-00, is now available as a spare part to use
as a service replacement for any commercial models (862/872 Series), however it must be
noted when fitting this revised water body to an existing heater manufactured pre-Feb 2018
it will also be necessary to replace the main PCB, part number 41-18376-00. Failure to
replace the PCB will result in the water heater not operating. NOTE: if the PCB socket for
the water body flow sensor plug is black (refer fig 2) this indicates that PCB has already
been modified and is compatible for use with revised water body and does not need to be
replaced again. Refer to TB18-001 for further details if required.
Water Body Field Service Replacements –Domestic Models:
Existing domestic models (874/876/864/866) manufactured pre-Jan 2018 that require a new
water body or PCB do not need to undergo this revision and will continue to use the original
water body, part number 20-51136-00 or PCB, part number 41-02890-00 as required for
service replacements.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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6 Star Release - From April 2012 production a revised 27L CF model will be produced. This
new model has a higher operational efficiency and therefore has been awarded a 6 star
rating. The new 6 star model is very similar to the 5 star model with the only difference
between the two models being model number, heat exchanger layout, GTC, fan speed and
the flue outlet on internal models.
The 5 and 6 star models can be differentiated by the model number. The model number of
the original 5 star units has a ‘0’ at the 4th digit i.e. 874027NF. The new 6 star models have
a ‘6’ at the 4th digit eg: 874627NF.
The 5 star internal models require a water heater flue adapter (p/n: 295121) to be fitted to
the flue outlet and if required a condensate drain section (p/n: 295120) is to be fitted directly
to this adaptor however the water heater flue adapter and the condensate drain are now
included as part of the 6 star heater’s flue outlet assembly (refer images below).
86X027 model (5 Star)
86X627 model (6 Star)
NOTE: If a condensation trap is not needed, the condensation spigot MUST have a cap and
clip to prevent exhaust gases escaping into the room on the 6 star product.
EZ-Link™system –With the release of the 6 star models it will no longer be mandatory for
a remote temperature controller to be fitted to EZ-Linked models. Where a remote is fitted
the unit with the remote connected is the master, whereas in a system where a remote is
not fitted the master must be determined by the installer by modifying the dip switch settings
(refer to page 27 for more information).

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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14
PRESET TEMPERATURE ADJUSTMENT
Factory pre-set and maximum hot water outlet temperature settings for each water heater
series are shown below:
Model
Factory setting
Maximum Temp
Solar
276, 866, 876
48ºC
48ºC*
N
244, 274, 374, 864, 101, 874**
60ºC
75ºC
Y
372, 862, 872**
60ºC
82ºC
Y
**When used as an inline solar booster these models must be set at a minimum outlet temperature of 70ºC.
Voltages up to 240 volts will be present within the water heater, take care
not to touch wiring terminals. Use an insulated tool when adjusting settings.
To check or adjust the preset outlet temperature setting:
1. Remove the front cover from the water heater.
2. Switch dip switches 3 and 4 to the ON (up) position on the DIP1 set of dip switches on
the PCB.
3. The current preset outlet temperature setting will be displayed on the LED1 display at
bottom right hand side of water heater.
4. Press the MIN button to decrease or the MAX button to increase the preset outlet
temperature setting to the desired setting. (The MIN and MAX buttons are located below
the dip switches.)
5. Turn dip switches 3 and 4 to the OFF (down) position on the DIP1 set of dip switches on
the PCB.
6. The LED1 display will go blank. The preset outlet temperature is now set.
7. Refit the front cover to the water heater.
*Outlet Temperature Compensation Adjustment (applicable to 50oC models only)
The maximum outlet temperature may be adjusted to compensate for temperature losses in
the pipe work between the water heater outlet and sanitary fixtures.
After adjustment the water temperature MUST NOT exceed 50°C from the first tap in the
hot water pipe work after the water heater used for personal hygiene purposes, such as in
a bathroom or ensuite.
If there is a tap, such as a kitchen or laundry tap, in the hot water pipe work between the
water heater and the first tap used for personal hygiene purposes, then it is possible for a
water temperature to be delivered from that tap of up to 2°C higher than the setting shown
on the controller.
It is necessary to have the electrical supply to the water heater switched on during the outlet
temperature compensation adjustment procedure.
NOTE:
This procedure cannot be conducted with a temperature controller connected to the
water heater. Any temperature controller(s) connected to the water heater must be
disconnected prior to the commencement of this procedure.
The preset outlet temperature setting of this water heater must be set at 48°C prior
to the commencement of this procedure.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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Outlet Temperature Compensation Adjustment Procedure:
To adjust the outlet temperature:
1. Disconnect all remote temperature controllers attached to the water heater.
2. Switch on the electrical supply at the power outlet to the water heater.
3. Locate the first hot tap in the hot water pipe work after the water heater used for personal
hygiene purposes.
4. Turn on the hot tap.
5. Using a thermometer, measure the temperature of the water from the tap, until the
temperature stops increasing. If the water temperature is below 50°C themaximum outlet
temperature of the water heater can be adjusted upwards.
6. Turn off the hot tap.
7. Switch off the electrical supply at the power outlet to the water heater.
8. Remove the screws holding the front panel to the jacket.
9. Gently disengage the front panel and pull forward to remove from the water heater.
10.Switch on the electrical supply at the power outlet to the water heater.
11.Switch dip switches 1 and 2 to the on (up) position on the DIP 2 set of DIP switches on
the I.C. Board. The temperature setting of “48” will show on the LED display, if this has
not previously been adjusted.
12.Press the MAX button once to increase the preset outlet temperature setting to the next
increment. Each press of the MAX button will increase the temperature setting by one
increment. The increments are: 48, 50, 51, & 52. The MAX button is located underneath
the DIP 1 and DIP 2 set of DIP switches.
13.Switch dip switches 1 and 2 to the off (down) position on the DIP 2 set of DIP switches
on the I.C. Board. The LED display will go blank.
14.Repeat steps 2 to 5. If the water temperature is still below 50°C and is required to be
increased, repeat steps 10 to 12, followed by steps 2 to 5 until an acceptable water
temperature not exceeding 50°C is measured at the same hot tap. If the water
temperature exceeds 50°C, then;
Switch dip switches 1 and 2 to the on (up) position on the DIP 2 set of DIP switches.
Press the MIN button once to decrease the preset outlet temperature setting to the
next increment. Each press of the MIN button will decrease the preset temperature
by one increment. (The MIN button is located underneath the DIP 1 and DIP 2 set of
DIP switches and to the left of the MAX button).
Switch dip switches 1 and 2 to the off (down) position on the DIP 2 set of DIP switches.
Repeat steps 2 to 5 to confirm the water temperature does not exceed 50°C.
15.Switch off the electrical supply at the power outlet to the water heater.
16.Refit the front panel and screws to the water heater.
17.Reconnect the controller cables (if a temperature controller is fitted).
18.Switch on the electrical supply at the power outlet to the water heater.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
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16
SEQUENCE OF OPERATION
Refer to ‘Sequence of Operation Component Diagram’ on page 17 to view components
shown in brackets e.g. (1)
1. When a hot water tap (1) is opened, cold water (or preheated water if a solar pre-heater
is installed) enters the water heater and passes through the Water Flow Sensor (3) and
Heat Exchanger (18). Note: The inlet water temperature must be less than or equal to
58ºC and less than or equal to the set point temperature minus 2ºC for operation to occur
past this point; otherwise water will pass straight through the heat exchanger and fan and
burner operation will not occur (for more information on this subject refer to the section
titled ‘In-series Gas Boosting’ on page 19).
2. The Water Flow Sensor (3) sends a pulse signal to the PCB (7). Once the pulse signal
reaches a pre designated frequency (at a min. flow rate of 2L/m the PCB (7) activates
the Fan Motor (24) and the Fan (23) starts rotating.
3. After the Fan (23) completes a pre purge to ensure the vent is clear, the Proportional
Gas Flow Regulator (12) allows gas to flow to the Burner (14).At the same time the
Igniter (15) starts sparking continuously and ignites the gas at the Burner (14).
4. After ignition the Flame Rods (17) sense and monitor the burner flame. The PCB (7)
constantly monitors all inputs to ensure the outlet water temperature is maintained within
1oC of the thermostat setting. The Proportional Gas Flow Regulator (12) continuously
adjusts the gas volume and the water flow is also adjusted to assist in supplying a stable
hot water temperature at all times.
5. As the gas flow rate, controlled by the Proportional Gas Flow Regulating Valve (12)
changes, the PCB (7) varies the speed of the Fan Motor (24) to maintain the correct air
gas mix ratio.
6. When the hot tap (1) is closed, the pulse signal from the Water Flow Sensor (3) stops
and the burner flame is extinguished by closing the gas valve. The post purge operation
then commences to cool the heat exchanger (18).
7. Once the post-purge operation is completed power to the Fan Motor (24) is cut and the
Fan (23) stops.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
17
Sequence of Operation Component Diagram
1)
Hot Water Tap
2)
Water Flow Servo Motor
3)
Water Flow Sensor
4)
Inlet Water Temperature Thermistor
5)
Combustion Chamber Thermistor
6)
Outlet Water Temperature Thermistor
7)
PCB
8)
Water Filter (Strainer)
9)
Gas Inlet Solenoid Valve
10)
Gas Solenoid Valve 1
11)
Gas Solenoid Valve 2
12)
Proportional Gas Flow Regulator
13)
Nozzle
14)
Burner
15)
Igniter
16)
Igniter Electrode
17)
Flame Sensor
18)
Heat Exchanger
19)
Over Temperature Limiter
20)
Exhaust (Flue) Outlet
21)
Combustion Chamber
22)
Anti Frost Heater
23)
Fan
24)
Fan Motor
25)
Drain Plug With Relief Valve.
26)
Controller (Optional)
Bypass Operation
The bypass is a section of copper pipe work connected between the water body assembly
and the outlet of the heat exchanger and allows a quantity of cold water to bypass the heat
exchanger. The purpose of the bypass is to ensure the heat exchanger operates at
temperatures above the dew point of the combustion gases, ensuring condensate is not
produced, but low enough to maximise the heat exchangers life. The PCB activates the
water bypass control motor based on heat exchanger temperature and selected outlet water
temperature.
Anti-Frost Heater Circuit
All models have an anti-frost heater circuit. The anti-frost heaters are wired in series and
operate independently from the water heater.
A thermostat sensing ambient air temperature, positioned in the wiring loom near the bottom
of the water heater, activates the anti-frost heaters when the ambient air temperature falls
to 4ºC (+4ºC/-2ºC) and deactivates the anti-frost heaters when the temperature rises above
12ºC.
In the event a heater block becomes open circuit the total heater circuit is rendered
inoperable. There are six anti-frost heaters in total.
Refer to ‘Anti-Frost Heaters’ on page 74 for replacement procedure.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
18
COMPONENTS AND THEIR FUNCTION
Water Body Assembly -A two part component that comprises the water volume control
assembly and the water bypass control assembly. The water volume control assembly
houses the water flow sensor and cold water inlet thermistor.
Proportional Gas Flow Regulator Valve (P.G.R.F.) -Gas valve that modulates and only
allows the amount of fuel needed to heat the water being used.
Flame Rod - Safety device that detects the presence of flame.
Igniter - Spark igniter that lights the main burner.
Thermistor(s) -A thermistor is an electronic thermostat that is used to measure
temperature. There are four thermistors: cold water inlet, hot water outlet, heat exchanger
and ambient air.
Hot water Outlet Valve -Valve that delivers hot water to the piping system and measure
the hot water outlet temperature with the aid of a thermistor.
Gas Inlet Connection -A connection port (separate from the gas valve) to connect the
incoming gas supply.
PCB (Printed Circuit Board) -The control board that processes all the inputs required to
make the heater operate.
Remote Temperature Controller -Digital control panel that allows user to adjust
temperature, monitor status of the machine and review certain maintenance functions.
Fan Assembly -Fan (blower motor) that draws fresh air into the heater to be mixed with
fuel for burning in the combustion chamber.
Burner Assembly -Burner component that ignites the fuel-air mixture and provides heat
for the heat exchanger.
Strainer - In-line filter on the cold water inlet assembly that filters out debris and sediment.
Gas type connector -Removable electronic chip that programs the fuel type, product type
and model number.
Overheat Limiter - a plastic film that wraps around the heat exchanger. It constantly
monitors the heat exchanger temperature and will show an Error Code 14 if the heat
exchanger gets too hot.

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
19
IN-SERIES GAS BOOSTING
Remote temperature controllers must not be fitted if this water heater is
installed as part of a solar water heater system because water at a
temperature much higher than the controller setting can be delivered.
50ºC models are not suitable for use as in-series solar gas boosters.
Only solar compatible models with a temperature setting of 70ºC or higher can be installed
as an in-series booster water heater to a solar preheat water heater. In this application the
outlet temperature setting of the heater must be set at a minimum of 70C to comply with
the requirements of AS3498. Refer to page 14 for details on checking and adjusting the
outlet temperature.
When the inlet water temperature is 58°C or higher the fan and burner will not operate
despite water flowing through the heat exchanger. When the inlet water temperature is less
than or equal to 57°C the burner will fire and boost the outlet temperature to 70°C provided
the flow rate is greater than 2 litres per minute.
Note: If an existing 871 series Integrity water heater with a bypass valve is replaced with a
new solar compatible CF heater, the solar bypass valve must be removed and the plumbing
connections remade directly to the inlet and outlet water connections of the replacement
water heater.
In-series Gas Boosting - Solar Loline Installation
Typical Installation - Solar In-Line Gas Booster
Solar Pumped Open Circuit Systems

TM049 27L Continuous Flow Service Instructions
REV AL –Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed “uncontrolled”.
20
In-series Gas Boosting - Solar Hiline Installation
TEMPERING VALVES
50 degree fixed models comply with AS/NZS 3498 and therefore do not require a tempering
valve to be fitted unless the unit is installed in an early childhood centre, school, nursing
home or a facility for young, aged, sick or disabled people.
It may be required by regulations that an approved
temperature limiting device be fitted on all other
models. Where a tempering valve is fitted and there is
not a separate untempered line for the kitchen or
laundry areas, the kitchen temperature controller will
be able to display temperatures above 50°C however
the delivered water temperature at the tap will be that
set by the tempering valve which will be no hotter than
50°C.
To enable delivery of hot water at temperatures above
50°C a separate untempered line must be provided
that supplies hot water exclusively to kitchen and
laundry areas (refer to diagram).
TYPICAL INSTALLATION
SOLAR OPEN CIRCUIT THERMOSIPHON WITH
IN-SERIES GAS BOOSTER

