Rinnai REU-VR1620WG User manual

SERVICE MANUAL
To Suit Models:
REU-VR1620WG
REU-VR1620WB
REU-VR1620WS
Does NOT Suit any other Models.
REU-VR2024WG

All Rinnai products are certified by the
Australian Gas Association as compliant
to relevant Australian Standards.
Rinnai Australia Head Office is certified
as complying with ISO 9001 by SAI
Global.
Rinnai New Zealand has been certified to
ISO 9001 Quality Assurance by Telarc.
All Rinnai products are Certified to
WaterMark by SAI Global. WaterMark
certification is awarded to products and
fittings complying with safety and water
contamination standards.
Distributed and serviced in Australia under a Quality
System certified as complying with ISO 9001 by
SAI Global
SAI Global

© Copyright Rinnai Australia Pty Ltd ABN 74 005 138 769
All rights reserved
Produced by Engineering & Technical Group
No portion or part of this manual may be copied without prior
permission from Rinnai Australia.
Rinnai Australia reserves the right to make modifications and change
specifications without notice.
Failure to comply with these instructions may result in serious personal
injury or damage to the appliance.
This manual has been published by Rinnai Australia Engineering &
Technical Group.
We welcome users of this manual to provide feedback and suggestions
for improvement purposes.
W A R N I N G
• All wiring inside this appliance may be at 240 Volts potential.
• All service work must be carried out by an authorised person.

REU-V1620WG / REU-V1620WB / REU-V1620WS / REU-V20204WG ) Issue 1 - 5/08/09 ©Rinnai
Glossary of Terms and Symbols
dB(A) - sound pressure level in decibels, “A” range
DC - direct current
AC - alternating current
WFCD - water flow control device
FB - feedback information
FF - feedforward information
Hz - Hertz
IC - integrated circuit
kPa - kilopascals
LED - light emitting diode
L/min - Litres per minute
mA - milliamps
MJ/h - megajoule per hour
mm - millimetres
OHS - overheat switch
PCB - printed circuit board
CPU - central processing unit
POT - potentiometer
rpm - revolutions per minute
SV - solenoid valve
ø - diameter
oC - temperature rise above ambient
POV - modulating valve
TE - thermal efficiency
TH - thermistor
TIN - temperature of incoming water
TOUT - temperature of outgoing water


REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 1 - Issue 1 - 5/08/09 ©Rinnai
Table of Contents
Glossary of Terms and Symbols ................................................................................ iv
1. Specifications ............................................................................................................. 1
2. Water Flow Rates and Pressures ................................................................................ 4
3. Dimensions ................................................................................................................ 5
4. Water Controllers ....................................................................................................... 6
5. Smartstart ................................................................................................................... 8
6. Cutaway Diagram .................................................................................................... 10
7. Operational Flow Chart ........................................................................................... 12
8. Operation Principles ................................................................................................ 13
9. Main Components .................................................................................................... 14
10. Time Charts ............................................................................................................ 15
11. Wiring Diagram ..................................................................................................... 16
12. Dip Switch Settings ............................................................................................... 17
13. Fault Finding .......................................................................................................... 18
14. Component and Circuit Checks ............................................................................. 20
15. Gas Pressure Setting Procedure ............................................................................. 25
16. Gas Conversion Procedure ..................................................................................... 25
17. Maintenance Monitor / Error History .................................................................... 26
18. Dismantling for Service ......................................................................................... 29
19. Parts List ................................................................................................................ 38
REU-VR1620WG / REU-VR1620WB / REU-VR1620WS .............................................39
REU-VR2024WG..............................................................................................................42
20. Exploded Diagram ................................................................................................. 45

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 1 - Issue 2 - 15/06/11 ©Rinnai
1. Specifications
Rinnai model number REU-VR1620WG
REU-VR1620WB
REU-VR1620WS
Type of appliance Temperature controlled continuous flow gas hot water system
Exhaust system Fan Forced Flue
Installation External
Dimensions Width - 350 mm
Height - 530 mm
Depth - 194 mm
Weight 15 kilograms
Gas consumption (Min. / Max.)
REU-V1620WG / REU-V1620WB
Natural gas : Approx. 14 ~ 125 MJ/h
Propane gas : Approx. 14 ~ 125 MJ/h
Output (kW) (Maximum) 28 kW
Connections
1620WG / WB
Gas connection - R3/4 (20A)
Cold water connection - R 1/2 (15A)
Hot water connection - R 1/2 (15A)
1620WS Cold water connection - R 3/4 (20A)
Hot water connection - R 3/4 (20A)
Ignition system Direct electronic ignition
Electrical consumption Normal - 47 W
Standby - 2 W (with 1 water control)
Anti-frost protection - 74 W
Hot water capacity (Raised 25°C) 2.3 to 16 L/min
Temperature range (with controller) Kitchen water controller : 37 ~ 55°C
Bathroom water controller: 37 ~ 50°C
Delivery temperatures 40°C, 42°C, 50°C, 55°C, 65°C, 75°C
(set by combination of dip switches on PCB)
NOTE: 1620WS must be preset to 60°C
Water flow control Water flow sensor, Electronic water flow control device
Maximum hot water capacity, raised @
25°C
16 L/min
Water pressure required to achieve
maximum hot water capacity
75 kPa
Maximum water flow 20 L/min
Water pressure required to achieve
maximum hot water flow
120 kPa
Minimum water flow 2.4 L/min
Power supply Appliance - AC 240 Volts 50 Hz
Water controller - DC 12 Volts
Water controllers (optional)
Water controllers not compatible with
1620WS
A maximum of 4 water controllers can be fitted. Any combination of
deluxe, universal and wireless controllers can be used with the
following limitations:
Only ONE master controller can be installed. This can be a MC-100V,
a MC-91Q (when programmed as a mater controller) or a MC-502RC/
MC-503RC water controller.
Up to TWO BC-100V water controllers can be installed.
The FOURTH water controller in any installation MUST be a
MC-502RC / MC-503RC or a MC-91Q.
Water Controller Cable Cables are supplied with water controllers. Alternatively, two core
sheathed (double insulated) flex with minimum cross sectional area of
0.5 m² may be used. Maximum individual cable runs should not
exceed 50 m.

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 2 - Issue 1 - 5/08/09 ©Rinnai
Rinnai model number REU-VR2024WG
Type of appliance Temperature controlled continuous flow gas hot water system
Exhaust system Fan Forced Flue
Installation External
Dimensions Width - 350 mm
Height - 530 mm
Depth - 194 mm
Weight 15 kilograms
Gas consumption (Min. / Max.)
REU-V1620WG / REU-V1620WB
Natural gas : Approx. 14 ~ 160 MJ/h
Propane gas : Approx. 14 ~ 160 MJ/h
Output (kW) (Maximum) 35.5 kW
Connections Gas connection - R3/4 (20A)
Cold water connection - R 3/4 (20A)
Hot water connection - R 3/4 (20A)
Ignition system Direct electronic ignition
Electrical consumption Normal - 65 W
Standby - 2 W (with 1 water control)
Anti-frost protection - 100 W
Delivery temperatures 40°C, 42°C, 50°C, 55°C, 65°C, 75°C
(set by combination of dip switches on PCB)
Water flow control Water flow sensor, electronic water flow control device
Maximum hot water capacity, raised @
25°C
20 L/min
Water pressure required to achieve
maximum hot water capacity
120 kPa
Maximum water flow 24 L/min
Maximum water flow, outlet temp < 60°C L/min
Water pressure required to achieve
maximum water flow
160 kPa
Minimum water flow for operation 2.4 L/min
Power supply Appliance - AC 240 Volts 50 Hz
Water controller - DC 12 Volts
Water controllers (optional)
- Wireless water controller only
installations
- Wired & Wireless Water Controller
Installations
A maximum of 4 water controllers can be fitted. Any combination of
deluxe, universal and wireless controllers can be used with the
following limitations:
Only ONE master controller can be installed. This can be a MC-100V,
a MC-91Q (when programmed as a mater controller) or a MC-502RC/
MC-503RC water controller.
Up to TWO BC-100V water controllers can be installed.
The FOURTH water controller in any installation MUST be a
MC-502RC / MC-503RC or a MC-91Q.
Water Controller Cable Cables are supplied with water controllers. Alternatively, two core
sheathed (double insulated) flex with minimum cross sectional area of
0.5 m² may be used. Maximum individual cable runs should not
exceed 50 m.

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 3 - Issue 1 - 5/08/09 ©Rinnai
Sensors and Safety Functions
•Hot Water Delivery Thermistor: Measures hot water temperature at the outlet valve (i.e. the ‘mixed’
temperature).
•Flame Rod: Monitors combustion characteristics inside the combustion chamber. If the flame fails, gas
supply is stopped.
•Overheat Switch: Situated on the heat exchanger, gas supply is stopped when water temperature
reaches 97ºC for a number of seconds.
•Fusible Link: Situated on the heat exchanger, electrical power supply is stopped if the temperature
exceeds 129ºC.
•Water Pressure Relief Valve: Safeguards the water circuit against excessive inlet pressure. Opens at
2060 kPa, closes at 1470 kPa.
•Electrical Fuse: (3A glass fuse) prevents against power surges.
•Surge Protector: prevents against over-current.
•Boil Dry Prevention: If water flow sensor detects no flow, gas supply is stopped.
•Combustion Fan Speed Sensor: In case of combustion fan defect (no rotation of fan blades) gas supply
is stopped.
•Temperature Cutout: If the delivered hot water temperature rises above the required delivery
temperature for a number of seconds, the gas supply is stopped.
Combustion Specifications
Refer to dataplate on the appliance.

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2. Water Flow Rates and Pressures
Water flow rate and pressure characteristics are shown below:
Water Flow vs Pressure Graphs
20.0
24.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0.0 50.0 100.0 150.0 200.0 250.0 300.0
Inlet pressure (kPa)
Outlet flow (litres/minute)
1620
2024
P(kPa) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 120.0 130.0 200.0 300.0
Q(L/min) 0.0 4.9 7.6 9.7 11.5 12.7 14.4 15.8 16.6 20.0 20.0 20.0 20.0
P(kPa) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0 160.0 200.0 300.0
Q(L/min) 0.0 4.2 6.7 9.3 11.0 12.2 13.6 15.1 16.1 17.1 18.2 19.2 20.0 24.0 24.0 24.0
1620
2024

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 5 - Issue 1 - 5/08/09 ©Rinnai
3. Dimensions
Dim' Description
AWidth
BDepth
CHeight - Unit
DHeight - Including Brackets
EHot Water outlet (from wall)
FHot Water outlet (from centre)
GCold Water inlet (from wall)
HCold Water inlet (from centre)
IGas Connection (from wall)
JGas Connection (from centre)
Gas: Length (from base)
Cold: Length (from base)
Hot: Length (from base)
Gas: Fitting Diameter
Cold: Fitting Diameter
Hot: Fitting Diameter
K
L
BC-100V
MC-100V
MC-91Q
90
120
83
120104
128
202
202022
181
B
D
C
K
REU-VR1620WG
REU-VR1620WB
REU-VR1620WS
350
194
530
571
87
105
68
10
77
83
40
50
39
20
15
15
A
E
FJ
H
I
G
L
FITTING
DIAMETER
* Please note that this measurement is to the left of the centre line.
83
REU-VR2024WG

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 6 - Issue 1 - 5/08/09 ©Rinnai
4. Water Controllers
All water controllers must be installed in accordance with the relevant operation/installation instructions
supplied with the water heater or controllers.
Trouble shooting
Water Controller not showing display - (Wired Water Controllers)
• Check that the correct number and combination of controllers have been installed for the specific
model Infinity. Refer to controller compatibility table below.
• Check controller is turned ON.
• Check there is 12VDC power supply available to the controller from the Ezi-connect terminals.
• If there is 12VDC available from the Ezi Connect but no controller display, check wiring between
Ezi-connect and controller is sound.
• If there is no power from the Ezi-connect terminals, but the hot water functions correctly, replace
PCB.
Error Code 12 as soon as hot water tap is turned ON.
• Check 12VDC internal wiring to Ezi-connect terminal is not crushed, or shortened.
• Rectify wiring and re-close Ezi-connect cover carefully.
Water Controller not showing display - (Wireless Water Controllers)
• Ensure transceiver module is mounted in the correct location, as per wireless controller installation
instructions.
• Ensure 2 x AA batteries are in good working order and installed with the correct polarity within the
wireless controller. (Battery polarity details on rear of wireless controller)
• Ensure distance between wireless controller and transceiver does not exceed 50 metres.
• Ensure channel has been allocated to each wireless controller.
• Ensure wireless controller has been programmed to the transceiver correctly, as per wireless
controller installation instructions.
Water Controller Compatibility Table
Care should be taken to ensure power supply to the Infinity is isolated when
connecting / disconnecting controller wiring or transponder on wireless controllers.
Failure to isolate power supply may result in damage to the appliance PCB.
Care should be taken when closing the Ezi-connect access panel, to ensure internal
wiring for controllers is not shortened or crushed.
Wireless Only
Installation
A maximum of 4 wireless water controllers can be fitted with the following limitation:
Only ONE MC-502RC or MC-503RC can be set as the Master Controller.
Wired &
Wireless
Installations
A maximum of 4 water controllers can be fitted. Any combination of deluxe, universal and
wireless controllers can be used with the following limitation:
Only ONE master controller can be installed. This can be a MC-100V, a MC-91Q (when
programmed as a master controller) or a MC-502RC or MC-503RC water controller.
Up to TWO BC-100V water controllers can be installed.
The FOURTH water controllers in any installation MUST BE a MC-502RC/MC-503RC
or a MC91Q.
NOTE

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 7 - Issue 1 - 5/08/09 ©Rinnai
PROGRAMMING FOR THE ‘UNIVERSAL’ WATER CONTROLLER (MC-91Q)
Are there four water controllers connected?
IF NO: (You have three water controllers or fewer), go to Question 2.
IF YES: You will need to activate the fourth water controller as follows:
STEP 1: For the water controller in the KITCHEN ONLY, press and hold
the ‘Transfer’ and ‘On/Off’ buttons simultaneously (see Fig. 5)
until a ‘beep’ is heard (approximately 5 seconds).
STEP 2: Check that the display on ALL FOUR water controllers is lit and
displaying a temperature when ‘switched on’. If any ONE of the
controller displays two dashes (see Fig. 6) repeat STEP 1.
This completes the activation procedure for the fourth controller,
you may ignore Question 2.
Fig. 5
Fig. 6
Is the water heater marked to state it delivers water not
exceeding 50°C?
IF YES: No further action required.
IF NO: You will need to program the kitchen controller to enable
selection of temperatures higher than 50°C.
STEP 1: For the controller in the KITCHEN ONLY, press and hold the
‘Transfer’ and ‘On/Off’ buttons simultaneously (Fig. 7) until a
‘beep’ is heard (approximately 5 seconds).
STEP 2: When the controller fitted in the KITCHEN is switched On, it
should be possible to select temperatures higher than 50°C. If not,
repeat STEP 1.
Fig. 7
If the water controller in the kitchen is replaced, repeat STEP 1 above for the
replacement controller.
If the water controller in the kitchen is swapped with another controller (for
example, the controller fitted in a bathroom), repeat STEP 1 for the controller
moved from the kitchen to the bathroom. Then perform STEP 1 for the controller
moved from bathroom to the kitchen.
QUESTION
QUESTION
NOTE

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 8 - Issue 1 - 5/08/09 ©Rinnai
5. Smartstart
At least one temperature controller model MC-91Q must be used in conjunction with the water heater and
the Smartstart® system. Alternatively, if water controllers cannot be used a manual activation switch must
be used. Water Controllers cannot be used with the 1620WS model.
The installation of the water heater and temperature controllers must be performed in accordance with the
installation instructions supplied with the water heater.
The Smartstart® system is designed for domestic installations. However, it may be suitable for certain non
domestic installations. See separate service manual for more information.
Principle of Operation (Fig.2)
The "Smartstart®" system heats the water in the pipework water connected between the water heater and
the hot water outlets before any outlets are opened using the 'flow and return' pipework principle. This
results in water savings and reduced waiting time for heated water delivery from the outlet when opened.
Traditional 'flow and return' systems usually keep the water in the pipework heated continuously. The
Smartstart® system however, only heats the water before the outlet is opened. This results in significant
energy savings because water is not heated unnecessarily whilst retaining the benefits of traditional flow
and return systems.
A schematic of the Smartstart® system installed in conjunction with a Rinnai continuous flow water heater
and temperature controller is shown in Fig.2 below.
If problems are experienced with Smartstart® operation refer to the Smartstart® Service Manual.
Figure 2 - Non Solar Hot Water Systems
H
O
T
C
O
L
D
G
A
S
C old Inlet Mains
Smartstart®
Module
R innai C ontinuous
Flow Water Heater
Hot W ater
Outlet
Hot W ater
Outlet
Heating Loop F low
Heating Loop R eturn
One or more
MC-91Q
C ontrollers
P reheat B utton

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 9 - Issue 1 - 5/08/09 ©Rinnai
Principle of Operation - Solar Hot Water Systems Only
Figure 3 - Principle of Operation - Solar Hot Water Systems Only
Gas Supply
Return Line
Isolation Valve
Non-Return Valve
Pressure Limiting 500 kPa Valve (Mandatory)
Line Strainer
Expansion Control 700 kPa Valve (Mandatory)
Cold Water
Supply
Smartstart installed with Rinnai gas boosted solar hot water system. Refer to Rinnai manuals supplied with appliances for important installation information. Installations MUST conform to local regulations.
Rinnai Smartstart Unit
Manual Activation Switch (not supplied)
Water controllers MUST NOT be used!
Solar Pump &
Controller Box
PTR Valve (supplied
with tank), rating as per
the tank’s data plate
Rinnai Continuous Flow Water
Heater - Gas Booster
WS
Outlets to Personal Hygiene areas to
be tempered to 50°C as per AS3500.4

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 10 - Issue 1 - 5/08/09 ©Rinnai
6. Cutaway Diagram
NOTE: This diagram is of a general nature. Some details may be different on some models
REU-VR1620

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 11 - Issue 1 - 5/08/09 ©Rinnai
REU-VR2024

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 12 - Issue 1 - 5/08/09 ©Rinnai
7. Operational Flow Chart

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 13 - Issue 1 - 5/08/09 ©Rinnai
8. Operation Principles
Hot Water Operation
1. Ignition
• Activate controllers (if fitted) and open the hot water tap (for full details regarding operation of water
controllers refer to the ‘Customer Operation and Installation’ manual.
• When water flows through the unit, the water flow sensor rotates and sends an electrical ‘pulse’
signal to the Printed Circuit Board (PCB). This signal is proportional to the water flow rate.
• The PCB sends electrical current to the combustion fan motor causing it to turn. The fan motor sends
an electrical pulse signal to the PCB. If fan rotation is OK, the main solenoid and changeover solenoid
valves open as required, the spark generator activates and the spark electrode ignites the burner.
2. Water Temperature / Flow Control / Volume Control
• The PCB will automatically control operation of the internal components to achieve the programmed
temperature. When a high temperature rise is required, the PCB may cause the Water Flow Servo to
close partially resulting in a lower flow rate to achieve the programmed temperature. This is a
necessary operational feature of the unit.
• When operating in ‘Bath Fill’ mode, the signal from the water flow sensor is also used by the PCB to
compute the volume of water that has been passed through the unit at any instant whilst the bath is
filling.
3. Shut Down
• When operating in ‘Bath Fill’ mode, the PCB causes the Water Flow Servo to close when the
programmed Bath Fill volume has passed through the unit. Alternatively, flow is stopped when the
user closes the hot water tap.
• When water flow stops, the water flow sensor stops rotating and the pulse signal to the PCB stops.
The PCB then causes the main solenoid and solenoid valves to close and the burner is extinguished.
The combustion fan will continue to operate for some time to purge the combustion chamber.

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9. Main Components
1) Printed Circuit Board (PCB)
• The Printed Circuit Board controls all operational functions including Air Supply Control, Gas
Control, Water Flow Measurement, Water Flow Control, Combustion System and all sensors and
safety devices.
2) Gas Flow Control
• During normal operation, the PCB keeps the main solenoid valve open whilst there is flow through the
unit and the burner needs to be lit.
• Gas flow rate is controlled by the modulating valve assembly and three changeover solenoid valves to
always ensure constant outlet water temperature, regardless of flow rate or incoming water
temperature.
• The modulating valve is electronically controlled by the PCB using signals from the water flow
sensor, water flow control device, water temperature thermistors and combustion fan speed sensor.
The modulating valve directs gas to the three changeover solenoid valves.
• The changeover solenoid valves direct gas to each of the two burner banks independently. Any one or
two or both of the solenoid valves may be open during operation.
• Gas flow is modulated by a combinationof the modulating valve and changeover solenoid positions.
• The maximum gas rate is predetermined and the appliance cannot be overloaded when correctly
installed.
3) Water Flow Control
• Water flow is detected by a turbine coupled to a magnetic pulse generating device. The magnetic
pulses are detected and counted by the PCB. The PCB calculates the exact water flow from the
frequency of pulses generated by the turbine, as well as the volume of water that has passed through
the unit at any instant during ‘Bath fill’ operation.
• Water flow control is achieved through the use of servo driven water flow and fixed bypass valves.
(Note: only some models have a bypass valve fitted). Both servo motors are controlled by the PCB.
The ‘Water Flow Valve’ restricts the flow of water into the heat exchanger assembly if the
programmed temperature cannot be achieved. During normal operation, cold water from the inlet
valve is mixed with hot water from the heat exchanger outlet.
• For models fitted with a ‘Bypass’ valve, it mixes the correct proportion of cold and hot water to ensure
accurate hot water delivery temperature over the available range of flow rates. The water flow and
bypass valves are a combined assembly on the cold water inlet of the appliance.
4) Air Supply Control
• Air for combustion is supplied by a centrifugal fan driven by a variable speed DC motor. The voltage
to the motor is determined by the PCB based on water flow, delivered water temperature and
programmed water temperature. The actual fan speed is monitored by a magnetic pulse counter. This
counter emits a signal to the PCB. From the voltage supplied to the DC motor and the fan speed
signal, the PCB determines whether an error condition exists with the fan.
5) Combustion System
The combustion chamber is housed within the heat exchanger assembly and comprises:
• A multi chamber aluminium alloy manifold with a multiple integral injectors. Gas flow to each
chamber is controlled by an electronic solenoid valve (refer ‘Gas Flow Control’ above).
• A burner assembly comprising multiple identical modular stainless steel bunsen burners secured by an
aluminised steel framework. The manifold is attached to the front of the burner module. Each bunsen
burner is supplied by two injectors.
• A combustion chamber. Integrated into the combustion chamber front panel are the flame rod and
ignition electrode(s).

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 15 - Issue 1 - 5/08/09 ©Rinnai
10. Time Charts
(* This Model only for the 2630 Series range)
Normal Combustion Sequence
Error Sequence (Ignition Flame Failure)
Pre-Purge Defect Sequence