Rinnai REU-VR3237WG User manual

To Suit Models:
Infinity 32
REU-VR3237WG
HD 250e
REU-VRM3237WC
Does NOT Suit any other Models
SERVICE MANUAL

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.
WARNING
WARNING

Infinity REU-VR3237WG /HD250e REU-VRM3237WC - iv - Issue 1 - 19/05/09 ©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
kcal/h - kilocalorie per hour
kPa - kilopascals
LED - light emitting diode
L/min - Litres per minute
mA - milliamps
MJ/h - megajoule per hour
mm - millimetres
mmH2O - millimetres of water (gauge pressure)
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


Infinity REU-VR3237WG / HD250e REU-VRM3237WC - v - Issue 1 - 19/05/09 ©Rinnai
Table of Contents
Glossary of Terms and Symbols ................................................................................ iv
Specifications ..................................................................................................... 1
Water Flow Rates and Pressures ....................................................................... 3
Dimensions ......................................................................................................... 4
Water Controllers ............................................................................................... 5
Smartstart ........................................................................................................... 7
Cutaway Diagram ............................................................................................... 8
Operational Flow Chart ...................................................................................... 9
Operation Principles ......................................................................................... 11
Main Components ............................................................................................ 12
Time Charts ...................................................................................................... 13
Wiring Diagram ................................................................................................. 14
Diagnostics Points ............................................................................................ 15
Dip Switch Settings .......................................................................................... 16
Fault Finding ..................................................................................................... 17
Component and Circuit Checks ........................................................................ 19
Gas Pressure Setting Procedure ...................................................................... 25
Gas Conversion Procedure .............................................................................. 25
Maintenance Monitor / Error History ................................................................. 26
Dismantling for Service .................................................................................... 29
Parts List .......................................................................................................... 35
Exploded Diagram ............................................................................................ 38

Infinity REU-VR3237WG / HD250e REU-VRM3237WC - 1 - Issue 1 - 19/05/09 ©Rinnai
1. Specifications
Rinnai model number REU-VR3237WG
REU-VRM3237WC
Type of appliance Temperature controlled continuous flow gas hot water system
Exhaust system Fan Forced Flue
Installation External
Dimensions Width - 470 mm
Height - 600 mm
Depth - 244 mm
Weight 29 kilograms
Gas consumption (Min. / Max.) Natural gas : Approx. 14 ~ 250 MJ/h
Propane gas : Approx. 14 ~ 250 MJ/h
Output (kW) (Maximum) 55.5 kW
Connections
1620WG / WB
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
Hot water capacity (Raised 25°C) 2.4 to 32 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, 85, 95°C
(set by combination of dip switches on PCB)
NOTE: 95°C appliance must be factory converted by Rinnai.
Water flow control Water flow sensor, Electronic water flow control device
Maximum hot water capacity, raised @
25°C
32 L/min
Water pressure required to achieve
maximum hot water capacity
140 kPa
Maximum water flow 37 L/min
Water pressure required to achieve
maximum hot water flow
190 kPa
Minimum water flow 2.4 L/min
Power supply Appliance - AC 240 Volts 50 Hz
Water controller - DC 12 Volts
Water controllers (optional) 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.

Infinity REU-VR3237WG / HD250e REU-VRM3237WC - 2 - Issue 1 - 19/05/09 ©Rinnai
Sensors and Safety Functions
•Hot Water Delivery Thermistor: Measures hot water temperature at the outlet valve (i.e. the ‘mixed’
temperature).
•Heat Exchanger Thermistor: Measures water temperature in the heat exchanger.
•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.

Infinity REU-VR3237WG / HD250e REU-VRM3237WC - 3 - Issue 1 - 19/05/09 ©Rinnai
2. Water Flow Rates and Pressures
Water flow vs inlet pressure 3237
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
Outlet Flow (litres/minute)
BPS Full Open
BPS Full Close
REU-VM3237W BPS full close
P(kPa) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 120.0 140.0 160.0 200.0 300.0
Q(L/min) 0.0 6.1 8.5 10.5 12.2 13.6 14.9 16.1 17.1 18.3 19.6 21.0 22.9 24.0 24.0 24.0
REU-VM3237W BPS full open
P(kPa) 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 120.0 140.0 160.0 180.0 190.0 200.0 300.0
Q(L/min) 0.0 9.0 12.1 14.8 17.1 19.1 20.9 22.4 24.1 25.5 26.9 29.3 31.6 34.0 36.0 37.0 37.7 37.7
BPS = Heat Exchanger Bypass Servo

Infinity REU-VR3237WG / HD250e REU-VRM3237WC - 4 - Issue 1 - 19/05/09 ©Rinnai
3. Dimensions
Dim' Description
REU-VR3237WG
REU-VRM3237WC
AWidth 470
BDepth 244
CHeight - Unit 600
DHeight - Including Brackets 644
EHot Water outlet (from wall) 115
FHot Water outlet (from centre) 61
GCold Water inlet (from wall) 99
HCold Water inlet (from centre) 52
IGas Connection (from wall) 61
JGas Connection (from centre) 110
Gas: Length (from base) 41
Cold: Length (from base) 51
Hot: Length (from base) 42
Gas: Fitting Diameter 20
Cold: Fitting Diameter 20
Hot: Fitting Diameter 20
K
L
BC-100V
MC-100V
MC-91Q
90
120
83
120104
128
202
202022
181
B
D
C
K
A
E
FJ
H
I
G
L
FITTING
DIAMETER
* Please note that this measurement is to the left of the centre line.
83

Infinity REU-VR3237WG /HD250e REU-VRM3237WC - 5 - Issue 1 - 19/05/09 ©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 water 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 water controller.
• Ensure wireless controller has been programmed to the transceiver correctly, as per wireless water
controller installation instructions.
Water Controller Compatibility Table
Wireless Only
Installation
A maximum of 4 wireless water controllers can be fitted with the following limitation:
Only ONE MC-502RC 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 water controller.
Up to TWO BC-100V water controllers can be installed.
The FOURTH water controllers in any installation MUST BE a MC-502RC or a
MC91Q.