Rinnai INFINITY 26i User manual

INFINITY 26i and HD50i
Infinity High Capacity Continuous Flow Gas Hot Water System
SERVICE MANUAL

The Rinnai Infinity 26i and
Heavy Duty 50i water heater,
when correctly installed, comply
with the requirements of the
United Kingdom Water Regula-
tions / Byelaws (Scotland).
These Products can be found
listed in the Water Fittings and
Materials Directory.
The Rinnai Infinity 26i water heater
is CE Marked for UK and Ireland as
allowed by Technigas of Belgium.
Certificate number E0716/5360
ID number 0461BO0739
Date of Issue 28 July 2003
Quality System Standard
ISO 9001 - 1994
The Design, Development, and Manufacture of Gas Water Heating Appliances
done under Rinnai’s Quality Management System is certified under the Quality
Management System Standard ISO 9001.
Registration Number JQ0003D
Registered since: February 1994
Certified by Japan Gas Appliances Inspection Association.

Produced by Rinnai Technical Services Department
August 2004- Issue 1.
No portion or part of this manual may be copied without prior permission from Rinnai U.K.
Rinnai U.K. 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 U.K. Technical Services. While many individuals
have contributed to this publication, it will be successful only if you - the reader and customer -
find it useful. We would like to extend an invitation to users of this manual to make contact with
us, as your feedback and suggestions are valuable resources for us to include as improvements.
Rinnai are constantly working toward supply improved appliances as well as information, and
specifications may be subject to alteration at any time.
Issue No1
WARNING
ALL WIRING INSIDE THIS APPLIANCE MAY BE AT 230 VOLTS POTENTIAL
ALL SERVICE WORK MUST BE CARRIED OUT BY AN AUTHORISED PERSON.
DO NOT TEST FOR GAS ESCAPES WITH AN OPEN FLAME

Infinity REU-V2632FFU / HD200I REU-V2632FFUC - iii - Issue 1 - 8/09/03 ©Rinnai
Table of Contents
Glossary of Terms and Symbols .................................................................................. iv
1. Introduction ................................................................................................................ 1
2. Specifications ............................................................................................................. 2
3. Water Flow Rates and Pressures ................................................................................ 4
4. Dimensions ................................................................................................................ 8
5. Remote Controls ........................................................................................................ 9
6. Cutaway Diagram .................................................................................................... 13
7. Operational Flow Chart ........................................................................................... 14
8. Operation Principles ................................................................................................ 15
9. Main Components .................................................................................................... 16
10. Time Charts ............................................................................................................ 18
11. Wiring Diagram ..................................................................................................... 19
12. Dip Switch Settings ............................................................................................... 20
13. Fault Finding .......................................................................................................... 21
14. Component Circuit Value Tabl.e / and checks........................................................ 23
15. Maintenance Monitor / Error History ................................................................... 31
16. Gas Pressure Setting Procedure ............................................................................ 33
17. Gas Conversion Procedure .................................................................................... 35
18. Dismantling for Service ........................................................................................ 44
19. Exploded Diagram ................................................................................................ 50
20. Parts List ............................................................................................................... 54
21. SERVICE CONTACT POINTS ..........................................................................58
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Infinity REU-V2632FFU / HD200I REU-V2632FFUC - iv - Issue 1 - 8/09/03 ©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
kW - kilowatts
LED - light emitting diode
L/min - Litres per minute
mA - milliamps
mbar -millibars of pressure
mm - millimetres
bar - 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
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nfinity 26i and HD50i

Infinity REU-V2632FFU / HD200I REU-V2632FFUC - 1 - Issue 1 - 8/09/03 ©Rinnai
1. Introduction
The Rinnai Infinity hot water units represents the latest technology in continuous flow, temperature
controlled hot water.
Features
• The Infinity 26iand HD50i NEVER RUN OUT of hot water. Whilst electricity, water and gas
supplies are connected, hot water is available whenever hot water taps are open.
• Built into the main micro-processor is the facility to LIMIT THE MAXIMUM TEMPERATURE of
the hot water supplied. The water temperature may be limited to various maximum temperatures. This
is particularly useful when the hot water unit is installed where young children or the infirm may be
using the hot water. The Infinity is delivered with a maximum preset temperature of 55 C and the
HD50i at 65° C. If required, the temperature limits can be changed by a service technician. For
further information, please contact Rinnai.
• The Infinity is a power flued appliance. It is COMPACT, saving both floor and wall space.
• The temperature of outgoing hot water is CONSTANTLY MONITORED by a BUILT-IN SENSOR. If
the temperature of the outgoing hot water rises to more than 3 C above the selected temperature
shown on the Digital Monitor (or the pre-set limit when Remote Controls are not fitted), the burner will
automatically go out. The burner will ignite again once the outgoing hot water temperature falls below
the temperature shown on the Digital Monitor (or the pre-set limit).
• The burner lights automatically when the hot water tap is opened, and goes out when the tap is closed.
IGNITION IS ELECTRONIC, therefore there is not pilot light. When the hot water tap is off, no gas is
used.
• ‘Deluxe’ or ‘Standard’ Remote Controllers are available as an optional extra. Depending on the models
chosen, these offer the following additional features :
- Bath fill function
- Voice Prompting
- Localised Temperature Control for up to four controllers
- Clock
• Temperatures selected at the controllers are retained in the SYSTEM MEMORY.
• Operating NOISE LEVEL IS VERY LOW.
• ERROR MESSAGES ARE DISPLAYED on the Remote Controllers, assisting with service.
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nfinity 26i and HD50i

Infinity REU-V2632FFU / HD200I REU-V2632FFUC - 2 - Issue 1 - 8/09/03 ©Rinnai
2. Specifications
Note 1: The default factory setting is 55ºC for the Infinity26i, and 65°C for HD50i. The unit can be ordered
from Rinnai to be pre-set to any of the other temperatures listed. The unit can be pre-set to any of the
temperatures listed by a suitably qualified person.
Controllers are available with default temperatures up to 75º C. When fitted with controllers, only
temperatures not exceeding the default temperatures can be selected. When fitted without controllers, the
unit will deliver water at the default temperature. Controllers are not available with 85° C settings.
Note 2: Unit will operate at lower pressures but the maximum rated flow of 32L/min. will not be achieved.
Model No. Infinity 26i and HD50i
Type of Appliance Temp.controlled continuous Flow Gas Hot Water Unit
Operation With/without remote controls, mounted in Kitchen, bathroom,etc.
Flue System Room Sealed - Forced Draught Flue
Installation Internally mounted (Indoor Only)
Available Default Temperatures (Note 1):
(without Remote Controllers)
40º C, 43º C, 50º C, 55º C, 60º C, 65º C, 75º C, 85º C
(set by combination of Dip switches on PCB)
Temperature Range (with Remote Controllers) Kitchen controller : 37 ~ 55º C
Bathroom controller : 37 ~ 50º C
Dimensions (mm)
Width 350
Height 600
Depth 224
Weight (Kg) 22
Connections
Gas 3/4 in. BSP
Cold Water Supply 3/4 in. BSP
Hot Water Supply 3/4 in. BSP
Ignition System Direct Electronic Ignition
Max. / Min. Gas
Consumption
Natural Gas 54 -- 4.4 kW
Propane Gas 54 -- 4.4 kW
Hot Water Delivery Capacity Max. 26 to 32 L/min.
Noise level 49 dB(A)
Thermal Efficiency 87%
NOXaf 55 ppm Max.
Minimum Operating Water Flow:2.4 L/min.
Minimum Operating Pressure (Note 2): 1.8bar
Maximum Operating Water flow 32 L/min.
Nominal Operat-
ing Pressure
Less than 60°C 1.4bar
Greater than or equal to 60°C 2.0~10.0bar
Power Supply Infinity Unit AC 230 Volts (50 Hz)
Remote Control (optional) DC 12 Volts (Digital)
Water temperature control Simulation feedforward and feedback
Water flow
control
Electronic Water flow sensor,flow control & heat exchanger
by-pass flow control.
Safety Device
Flame Failure Flame rod
Boil dry Water flow sensor
Remaining Flame (OHS) 97º C bi-metal switch
Over temperature 95º C lockout thermistor
Fusible link 129º C Thermal Fuse
Pressure relief valve Opens 20.6bar,closes14.7bar
Combustion fan rpm check Integrated circuit system
Over current Glass fuse (3 Amp).
Remote
Controllers
(optional)
Kitchen MC91-1A or MC-70-2A
Bathroom MC91-1A or BC-70-2A
Second Bathroom MC91-1A or BC-70-2A
Third Bathroom MC91-1A
Remote Controller Cable (Optional) Two core sheathed (double insulated) flex with min.cross-sectional area of 0.5 mm²
Electrical
Consumption
Normal 80W
Standby 7.5 W (with 1 Remote Control)
Manifold Electronic Control System (Optional) MSA-2M, MSA-2S
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Sensors and Safety Devices
• Heat Exchanger Thermistor: Measures hot water temperature at heat exchanger outlet. If water
temperature reaches a predetermined limit, gas supply is stopped.
• 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
20.6bar, closes at 14.7bar.
• Electrical Fuse: (3A glass fuse) prevents against over-current.
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) 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
* * The TPP is measured with the cover ‘off’ the appliance at the regulator test point with supply pressures
of 20 mbar (NG) and37 mbar (Propane).
Gas Type Injector
Size (mm)
Upper /
Lower
Nominal TPP (mbar)* * Gas Input (kW)
Low High Low High
Natural
1.00
1.98.54.4 54
1.7
Propane 0.75
2.310.84.4 54
1.15
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nfinity 26i and HD50i

Infinity REU-V2632FFU / HD200I REU-V2632FFUC - 4 - Issue 1 - 8/09/03 ©Rinnai
3. Water Flow Rates and Pressures
Water Flows
Table 1 shows unmixed and mixed water flow rates and approximate gas consumptions for various
temperature rises. The unmixed flow rates are the flow rates available at the given temperature rise directly
at the outlet of the water heater. The mixed water flow rates are available at the given temperature rise by
mixing hot water from the outlet of the water heater with cold water from the mains supply.
Water Flows can also be calculated by the following formula:
M = 60 x ( Q / C x T )
Where M = Water flow rate in litres/minute. If M is dto 26, the water is unmixed. If M is !, the water
is mixed.
Q = Heat energy output in kW = 47kW for the Infinity 26i and HD50i
C = Specific heat of water = 4.2KJ/Kg C. C does not change for the purpose of this calculation.
T = Temperature rise required ( C)
Example:
What is the flow rate available with an incoming water temperature of 10 C and a required temperature of
20 C?
T = 20 - 10 = 10 C
Q = 47
C = 4.2
M = 60 x ( 47 / (4.2 x 10) ) = 67 l/min. Since 67 is greater than 26 this flow rate is mixed. This result
corresponds with the value in Table 1.
Table 1: Approximate Water Flows & Gas Usage - Rinnai Infinity 26i and HD50i - Preset Table
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nfinity 26i and HD50i

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Table 1. Approx. Water Flows & Gas Usage - Rinnai 26i and HD50i Preset Temp. Less than 60°C.
Temp Rise
(º C)
Approx.
Min / Max
Gas Input
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
Infinity 26 i and HD 50i
4.4-54 0.53 32 1920 1.4 13 0.53 32 1920 1.4 26 0.53 32 1920 1.4 39 0.53 32 1920 1.4 52
Temp Rise
(º C)
Approx.
Min / Max
Gas Input
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
Infinity 26 i and HD 50i 4.4-54 0.44 26.4 1584 1.0 54 0.37 22.2 1332 0.65 54 0.32 19.2 1152 0.5 54 0.28 16.8 1008 0.4 54
Temp Rise
(º C)
Approx.
Min / Max
Gas Input
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
Infinity 26 i and HD 50i 4.4-54 0.25 15 900 0.3 54 0.22 13.2 792 0.25 54 0.2 12 720 0.23 54 0.19 11.4 684 0.2 54
Temp Rise
(º C)
Approx.
Min / Max
Gas Input
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
L/sec L/min L/hr
Min Water
Pressure
bar
Approx
Gas
Cons.
kW
Infinity 26 i and HD 50i 4.4-54 0.17 10.2 612 0.19 54 0.16 9.6 576 0.18 54 0.15 9 540 0.17 54 0.14 8.4 504 0.16 54
Models (Preset temps
less than 60 C)
20
30 35 40 10 15 50 55 60
65 70 75 80
Models (Preset temps
less than 60 C)
25
Models (Preset temps
less than 60 C)
45
5
Models (Preset temps
less than 60 C)
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nfinity 26i and HD50i