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.

REU-VR1620WG / REU-VR1620WB / REU-VR1620WS / REU-VR2024WG- 4 - Issue 1 - 5/08/09 ©Rinnai
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