Noritz SCU-401-12M User manual

SBB80UX-2
Disconnect
Power Ground
System Controller
SCU-401-12M,-24M
Requests to Installers
Potential dangers from accidents during installation and use are divided into the following two categories.
Closely observe these warnings, they are critical to your safety.
WARNING indicates a potentially hazardous situation which, if not avoided, could result
in death or serious injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in
minor or moderate injury.
WARNING
CAUTION
• Failures and damage caused by erroneous work or work not as instructed in this manual are not covered by the warranty.
• Refer to installation manual attached to the appliance as well.
• Check that installation was done in accordance with this Installation Manual upon completion.
• After completion of installation, be sure to hand this Installation Manual to the customer.
• When you fasten the screws on the terminals (Warning lamp terminal and so on),do not use electric drivers,
impact drivers and so forth.Tightening with excessive force may cause the terminals to be damaged and lead
to failures.
In order to use this product safely, read this installation manual carefully and follow
the installation instructions.
WARNING
Contents
1. Included Accessories ................................................. 2
2. Optional Accessories ................................................. 2
3. Introduction ................................................................ 3
4. Installing the System Controller ................................. 4
5. Wiring Diagram .......................................................... 7
------------------------------ [RC-9018M]-----------------------------
6. Remote Controller...................................................... 8
7. Remote initial setup .................................................. 10
8. Recirculation Pump Timer Setup .............................. 14
9. System Check Button ................................................... 16
10. Maintenance Monitors and Additional Settings ......... 17
11. Additional Remote features .......................................... 19
------------------------------ [RC-7649M]-----------------------------
12. Remote Controller.................................................... 21
13. Remote initial setup ................................................. 22
14. Additional Remote features .......................................... 25
----------------------------------------------------------------------------
15. Additional System Controller Features ....................... 28
16. System design, Gas, and Water piping ...................... 32
17. Follow-up Service .................................................... 36
18. Dimensions .............................................................. 37
----------------------------Service Manual---------------------------
19. Procedure for replacing Main Controller in the System Controller ..... 38
20. Procedure for replacing Sub Controller in the System Controller ...... 39
If at any time during the installation and setup of this product you have questions or concerns, contact Noritz America at 866-
766-7489 or visit http://support.noritz.com/.
Rev. 03/21
Note: If the system controller (SCU-401-12M,-24M) is installed in conjunction with the NC380-SV-ASME (with
remote controller RC-7649M), the initial settings (refer to page 22) must be followed. Failure to change the
initial settings may result in an error code “730” appearing on the remote controller.
Installation Manual
─1─

2. Optional Accessories
Name Usage Qty
*2
Remote controller
RC-9018M
*2
Always necessary except using NC380-SV-ASME. 1
Remote controller Cord
RC-CORD10
RC-CORD26
-The communication cord between the system controller and the
remote controller can be lengthened up to a maximum total length
of 450 feet.
-The communication cord between the system controller and each
water heater can be lengthened up to a maximum total length of
45 feet.
Total number of units
in system + 1
*3
NWC-ADAPTER
(NAW-1 US)
For remote monitoring the multi-unit system through the Mobile App. 1
For the combined use pattern
Number of units System controller Remote controller
7 to 12 SCU-401-12M *2 RC-9018M
13 to 24 SCU-401-24M
Part Shape Qty Part Shape Qty
Anchoring Screw 5
*1
1
1. Included Accessories Check for any missing items
before starting installation.
*1 Attached in the system controller.
When two or more multi-unit systems are installed in parallel
One remote controller is necessary for each multi-unit system (i. e. 3 multi-unit systems will require 3 system controllers
and 3 remote controllers). Each system will have separately wired remote controller cords.
A. When there is no circulation pipe (standard type)
CAUTION : Be sure to use the remote controller cord as listed above. If a di󰀨erent cord is used, the equipment may fail or not operate
properly.
Assembly &
Setup Instructions
Condition Number of units System controller Remote controller
Recirculation type
(circulation heat-retention with external pump)
7 to 12 SCU-401-12M
*2
RC-9018M
13 to 24 SCU-401-24M
Storage Tank Recirculation type
(circulation heat-retention with external pump)
7 to 12 SCU-401-12M
13 to 24 SCU-401-24M
B. When there is a circulation pipe
*2 : RC-7649M only may be used when using NC380-SV-ASME.
*3 : NWC-ADAPTER is not compatible with NC-380-SV-ASME.
*2 : RC-7649M only may be used when using NC380-SV-ASME.
*2 : RC-7649M only may be used when using NC380-SV-ASME.
─2─

3. Introduction (see list of points below)
This manual is intended to provide instruction for the installation, operation, and features of the SCU-401 system
controller. It is divided into 4 main sections:
1. Installation of the SCU-401 system controller
2. Initial programming of the remote controller
3. Additional features of the remote controller and the SCU-401 system controller
4. Plumbing diagrams and general information about water and gas piping
Read this manual carefully and follow the instructions as written.
If you have any questions, contact Noritz America at 866-766-7489 or visit http://support.
noritz.com/.
Introduction to the “SCU-401” System Controller
Overview
Basic Operation
The SCU-401 system controller is used to combine 7 to 12 / 13 to 24 Noritz heaters into a single “multi-unit system.”
The system controller stages units on and o󰀨 based on hot water demand and rotates their operation to ensure even
usage. It also has two additional modes which optimize the system for operation with a recirculation line or storage
tank.(Note: for systems of 1 to 6 units use the SC-401-6M system controller)
Unit Staging
Staging allows the multi-unit system to track hot water demand from the minimum ow rate of a single unit up to the
maximum output of several units. When the primary ring heater reaches ~50% of its maximum output, the system
controller activates the next unit in the system. When both these units reach ~50% of their maximum output, a third
unit is activated and so on. The SCU-401 may also be congured to activate two heaters during primary ring to allow
for rapid initial hot water demand.
Unit Rotation
The SCU-401 system controller rotates operation of the primary ring heater every 8 hours of combustion time.
This helps to ensure even usage of all units.
Water heater Instant hot
water is
available.
<Recirc>
Hot water is circulated
in the piping.
The system controller
operates these pumps.
Pump
Pump
<Tank recirc>
The system controller
operates these pumps.
Pump
Pump
Hot water
storage
tank
Instant hot
water is
available.
Water heater
Pump
Hot water is circulated
to the tank.
* These diagrams are for illustration purposes only.
System Selection
The SCU-401 allows the user to select two additional system types: “Recirc” and “Tank recirc.” These settings optimize
performance with recirculation and storage tank systems, and allow the system controller to operate one or two pumps.
GROUP 1 GROUP 2 GROUP 4
UNIT1 UNIT2 UNIT3 UNIT4 UNIT5 UNIT6 UNIT7 UNIT8 UNIT9 UNIT10 UNIT11 UNIT12 UNIT19 UNIT20 UNIT21 UNIT22 UNIT23 UNIT24
1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 19th 20th 21st 22nd 23rd 24th
Rotation
6th 1st 2nd 3rd 4th 5th 12th 7th 8th 9th 10th 11th 24th 19th 20th 21st 22nd 23rd
Rotation
2nd 3rd 4th 5th 6th 1st 8th 9th 10th 11th 12th 7th 20th 21st 22nd 23rd 24th 19th
Rotation
19th 20th 21st 22nd 23rd 24th 1st 2nd 3rd 4th 5th 6th 13th 14th 15th 16th 17th 18th
Rotation
24th 19th 20th 21st 22nd 23rd 6th 1st 2nd 3rd 4th 5th 18th 13th 14th 15th 16th 17th
Rotation
14th 15th 16th 17th 18th 13th 20th 21st 22nd 23rd 24th 19th 8th 9th 10th 11th 12th 7th
Rotation
7th 8th 9th 10th 11th 12th 13th 14th 15th 16th 17th 18th 1st 2nd 3rd 4th 5th 6th
Rotation
12th 7th 8th 9th 10th 11th 18th 13th 14th 15th 16th 17th 6th 1st 2nd 3rd 4th 5th
Rotation
20th 21st 22nd 23rd 24th 19th 14th 15th 16th 17th 18th 13th 2nd 3rd 4th 5th 6th 1st
For
SCU-401-12M
─3─

● The weight of the device will be applied to the wall. If the strength of the wall is not su󰀩cient, reinforcement
must be done to prevent the transfer of vibration.
● Do not drop or apply unnecessary force to the device when installing. Internal parts may be damaged and
may become highly dangerous.
● Install the unit on a vertical wall and ensure that it is level.
Be sure to do
Location of Screw Hole
Locating Screw Holes
Check
4. Drill holes for the remaining four screws.
Use wall anchors if necessary.
5. Hang the unit again by the rst screw, and then insert and tighten
the remaining four screws.
6. Take waterproong measures so that water does not enter the
building from screws mounting the device.
• Make sure the unit is installed securely so that it will not fall or
move due to vibrations or earthquakes.
1. Drill a single screw hole, making sure to hit a stud.
2. Insert and tighten the screw and hang the unit by the upper
wall mounting bracket.
3. Determine and mark the positions for the remaining four
screws (two for the top bracket and two for the bottom), and
remove the unit.
Locating Screw Holes
Mounting
Structure
• When installing with bare hands, take caution to not inict injury.
• We recommend using gloves.
• Be careful not to hit electrical wiring, gas, or water piping
while drilling holes.
Item
CAUTION
Illustration
Mounting Bracket
(upper)
Anchoring
Screws
Anchoring
Screws
Wall
Anchors
4. Installing the System Controller
Securing to the wall
This appliance must be electrically grounded in accordance with local codes, or in the absence of local codes, with the National
Electrical Code, ANSI/NFPA 70. In Canada, the latest CSA C22.1 Electrical Code.
Caution: Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous
operation.
Verify proper operation after servicing.
Field wiring to be performed at time of appliance installation.
Electrical Wiring Consult a qualied electrician for the electrical work.
- Do not connect electrical power to all water heaters and system controller (do not turn ON
the power supply) before all electric wiring is completed. Otherwise, electric shock or failure
of the water heater and system controller may occur.
- If a remote controller cord is not connected, there is a case that unexpected temperature
ows out. So check it is surely connected.
- Be sure to tighten the screw to the terminal block manually and do not use an electric
screwdriver or impact driver. Otherwise, the terminal block may be damaged.
CAUTION
─4─

Ground
• To prevent electrical shock, provide a ground with resistance less than 100 .
An electrician should do this work.
Do not connect the ground to the city water or gas piping. Do not tie the ground to a telephone line.
Breaker Installation
• Mount a device which shuts o󰀨 the electrical path automatically (leakage breaker) when electrical leakage is detected.
• The electrical supply required by the system controller
is 120VAC at 60 Hz.
Use an appropriate circuit.
• Do not let the power cord contact the gas piping.
Tie the redundant power cord outside the system
controller. Putting the redundant length of cord inside
the system controller may cause electrical interference
and faulty operation.
Electrical Shock Hazard
Do not turn power on until electrical wiring is nished. Disconnect power before servicing.
Failure to do so may result in death or serious injury from electrical shock.
WARNING
Electrostatic discharge can a󰀨ect electronic components. Take precautions to prevent electrostatic discharges from personnel
or hand tools during the system controller installation and servicing to protect the product’s electronic control.
CAUTION
• For instructions on connecting the power cord, refer to
the “Procedure of connecting the power cord to system
controller” sheet attached in the system controller.
Remote Controller Terminal Bloc
k
(Inside System Controller)
Remote controller cord
To remote controller
* There are two sets of remote controller terminals.
It is okay to connect to one or the other, but not both.
Only one remote controller may be connected.
Remote
controller 1
Remote
controller 2
System controller
1. Pass the remote controller cord through one (need to be cut to make a hole) of
the grommets in the base of the system controller. Connect the Y terminals to the
remote controller terminal block as shown below.
2. Install the remote controller as outlined in the water heater installation manual.
* Do not connect the communication cord from the units to the remote controller terminal block.
A malfunction will occur.
Connect the communication cord with the remote controller.
Connection with Remote controller
─5─

Before making wiring connections from each unit to the system controller, make sure that
the electrical power of each unit including the system controller has been disconnected.
1. Remove the front cover from the system controller and the cover of the external re-
mote controller cord terminal block of each water heater.
Connecting the communication cord to Unit 1
2. Using the remote controller cord supplied with the water heater, insert the end with
Y terminals through one (need to be cut to make a hole) of the grommets in the
base of the system controller. Connect the Y terminals to terminal block “01”.
3. Cut o󰀨 the connector on the other end of the remote controller cord. Attach the Y
terminals in place of the connector.
4. Connect the free end of the remote controller cord to the external remote controller
cord terminal block of Unit 1.
Connecting the communication cord to Units 2-24
5. Connect Units 2-24 in the same way as Unit 1. Be sure to connect the units to the
water heater terminals in the system controller, following the list of connections of
water heaters.
* For the terminal block that is not used, nothing should be done.
* After all connections are made, replace the front cover of the system controller
(taking special care to do not crush any wires) and the covers of the external remote
controller cord terminal blocks of all connected water heaters.
01 02 03 04 05 06
Water Heater Terminals (Inside System Controller)
Terminal block* for remote controller cord.
* The terminal block is depending on each water heater.
Refer to the water heater's installation manual for detail information.
Remote controller cords
Unit 1 Unit 2 Unit 3
Group 1
Main
Controller
Power
PCB
Sub Controller 1 Sub Controller 2
Group 2
Group 3Group 4
System Controller
Connect the communication cords with the water heaters.
Connection with Water Heater
List of connections of water heaters
Group No. Group 1 Group 2 Group 3 (Only -24M) Group 4 (Only -24M)
Number of
connected units
Sub power of
each sub
controller ○○○○
Water Heater
Terminal No. 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Group 1 Group 2 Group 3 Group 4
Number of Water Heaters
7 units 4 units 3 units 0 units 0 unit
8 units 4 units 4 units 0 units 0 unit
9 units 5 units 4 units 0 units 0 unit
10 units 5 units 5 units 0 units 0 unit
11 units 6 units 5 units 0 units 0 unit
12 units 6 units 6 units 0 units 0 unit
13 units 6 units 5 units 2 units 0 unit
14 units 6 units 6 units 2 units 0 unit
15 units 6 units 6 units 3 units 0 unit
16 units 6 units 6 units 4 units 0 unit
17 units 6 units 6 units 5 units 0 unit
18 units 6 units 6 units 6 units 0 unit
19 units 6 units 6 units 5 units 2 units
20 units 6 units 6 units 6 units 2 units
21 units 6 units 6 units 6 units 3 units
22 units 6 units 6 units 6 units 4 units
23 units 6 units 6 units 6 units 5 units
24 units 6 units 6 units 6 units 6 units
*Connect water heaters at the gray points.
─6─

120VAC, 60Hz
System Controller
Water heater
Terminals
(Units 1 - 24)
Remote Controller Cord
Remote Controller Cord
Remote Controller Cord
Remote Controller Cord
terminal block
Remote Controller Cord
terminal block
Remote Controller Cord
terminal block
PCB
Power
PCB
PCB
Power
PCB
PCB
Power
PCB
Remote Controller Cord
Remote
Controller
System Controller
power supply
* The power cord is not supplied with System Controller.
(For procedure of connecting the power cord, refer to “Procedure of connecting
the power cord to System Controller” sheet stuck into the system Controller.)
Unit 1
Unit 2
Unit 3
Main
Controller
Power
PCB
Sub Controller 1 Sub Controller 2 Sub Controller 3 Sub Controller 4
Disconnect this
Connector
Disconnect for
system controller
NC380-SV-ASME only
* This connector must
be disconnected in
each unit.
CAUTION
• The below diagram shows the connection of 3 units to the system controller.
When connecting 4 or more units, follow the same procedure.
• Connect the water heaters to the system controller following the detailed wiring instructions
included with the system controller.
• Always connect a remote controller to the system controller.
* The remote controller terminal location
may di󰀨er depending on the unit.
5. Wiring Diagram
─7─

The remote controller will emit a tone when a button is pressed.
Remote Controller (Required Accessory : RC-9018M)
*Using NC380 models, refer to RC-7649M section (page 21).
Activates the automatic water heater power
“ON” or “OFF” setting as determined by the
user selected schedule.
For turning the water heater
on/o󰀨.
(Next page)
Locks remote controller
operation. (page 20.)
Check the status of the
system or the number of
installed units.
(page 16, 36.)
Returns to the previous
screen while making system
settings or checking status.
Conrms changes
made by the user.
For setting the hot water
temperature, and
other settings.
* Use to change system
settings or to return to
the home screen.
* If you press the menu button
and press the temperature
setting buttons,
is sometimes displayed.
However, do not use this
mode as it is meant
for installation or service
personnel only.
Stops the tone that is emitted
when an error occurs.
(page 36.)
Cover shown in
the open position.
Prog Button / Indicator (Red)
Power ON / OFF Button
/ Indicator (Green)
Menu Button
Back Button
Alarm O󰀨 Button
/ Indicator (Red)
Speaker
Display Screen
Status Button
Lock Button
Enter Button
Hot Water Temperature
Setting Buttons
The part number is
printed on the surface
of the cover.
6. Remote Controller
* This Remote Controller is not resistant to water, steam, chemicals, or UV rays. Install it in a location where it will not
be exposed to these conditions. If it must be installed outdoors, use a weatherproof enclosure. Refer the RC-9018M
Installation Manual for details.
Remote Controller
Part Number
─8─

(Ex.: 10:15 am)
* The screen display shown below is for illustration purposes only.
The actual display will vary depending on how the water heater is being used.
* After a button is pressed, the display will gradually become darker to prevent unnecessary power consumption
by the remote controller.
(Ex.: 110°F)
The ame symbol is displayed during
combustion when using hot water or
recirculation functions.
A number will ash if a
failure occurs. (page 36.)
<Home Screen Example>
Screen Display
What is the home screen?
The home screen is displayed when the button is "ON".
Normally, the hot water temperature and the clock, etc. are displayed.
Flame Symbol
During normal operation, the set
temperature is displayed.
Display for Recirculation Operation
Display for High Temperature
Temperature Setting
Clock Display
Error Code
* For systems that use recirculation operation, the symbol
is displayed when the Power ON/OFF button is set to "ON".
* It is displayed during the recirculation operation.
Display for Temperature Setting
The lock symbol is displayed
when the remote controller is
locked. (page 20.)
Locked Display
The clock symbol is displayed
when the recirculation timer is
activated. (page 14 - 15.)
Recirculation Timer
Displays when the set temperature
is 125°F/55°C (131°F) or higher.
Note: As shipped from the factory, the remote controller is set to display in °F and gallons.
To adjust the display to °C and liters, refer to the
page 13
.
─9─

7. Remote initial setup
Note: When power is rst connected to the multi-unit system (system
controller and units), the remote enters an initial setting mode.
The following instructions explain how to perform an initial setting.
If you need to change these settings at a future date, follow the
instructions titled System Selection and Settings in the “Initial
Settings” Screen (page 11 - 13).
Initial Setting Procedure in the “System Settings” Screen
1
2
3
Preparation
Press the button on the remote.
Operation Screen Display Description
Connect power to all heaters and system controller
in multi-unit system.
1) You will be prompted to choose
a system type.
2) Use the buttons to navigate
to the correct system type.
(Standard, Recirc., or Tank Recirc.)
3) Press the button to
select your system type.
1) If you chose the “Recirc.” or
“Tank Recirc.” systems, you
will be prompted to turn pump
rotation on or off (this setting
is set to “off” by default).
2) Use the buttons to select
yes (on) or no (off).
3) Press the button to set
the pump rotation.
41) You will now be prompted to
“complete system setting.”
2) Press the button to
complete the system setting.
3) Once you choose “Complete
system settings?”, the
remote will display “System
settings completed”.
* Note: if you chose standard system in
step 2 - 2), you will immediately go to
this prompt.
* You may use the button to
return to the previous menu at any
time.
* Note: only when you connect one/two
pumps to the system controller, you
need to select “Yes” or “No”.
─10─

Note: Use this procedure if you need to change the system type or
settings after running the “initial setting procedure”
System Selection and Settings in the “Initial Settings” Screen
1
2
3
Preparation
Press the button.
Operation Screen Display Description
Use the buttons “▼” to
navigate to “Initial settings.”
Press the button to access
the initial settings menu.
Access Initial Settings Menu.
1) Turn Remote off.
2) Disconnect Power to all heaters and system
controller in the multi-unit system.
3) Wait 10 seconds or more.
4) Reconnect power, DO NOT turn remote on.
Change System Type
1
2
3
In the initial settings menu select
“System type”.
The menu will have three options:
Standard, Recirc., and Tank Recirc.
1) Use the buttons to navigate
to the appropriate system.
2) Press the button to select
the desired system.
4Once a system is selected, the
remote will display “Set Complete”.
* You may use the button to
return to the previous menu at any
time.
* You may use the button to
return to the previous menu at any
time.
List of the Initial settings
System type The system type can be changed.
Sys settings The system settings can be changed.
[°F/gal]<
=
>[°C/L] The unit of temperature and ow rate on the screen can
be changed.
Adjust clock The gap of time per month on the clock can be adjusted.
Save backlight The power saving setting of the backlight on the screen
can be changed.
─11─

When you start using the system, cold
water in the piping must be discharged
before receiving hot water.
Water heater
<Standard>
Water heater Instant hot
water is
available.
<Recirc>
Hot water is circulated
in the piping.
The system controller
operates these pumps.
Pump
Pump
<Tank recirc>
The system controller
operates these pumps.
Pump
Pump
Hot water
storage
tank
Instant hot
water is
available.
Water heater
Pump
Hot water is circulated
to the tank.
* These diagrams are for illustration purposes only.
1
2
3
Operation Screen Display Description
Change System Settings.
In the initial settings menu
select “Sys settings”.
1) The “Sys settings” menu will
display several options for
the selected system type.
2) Press the button to
select the system setting
you would like to alter.
1) Use the buttons to turn the
feature on (“yes”) or off (“no”).
2) Press the button to
select “yes” or “no”.
3) The display will say “Set complete”
once an option is chosen.
* You may use the button to
return to the previous menu at any
time.
List of the Sys settings
Item in the Sys
settings
system type Yes No
Standard Recirc Tank recirc
Quick staging Available Available Not
Available
Units will stage more rapidly from
heater to heater*
Units will stage more slowly
Pump error check Not
Available
Available Available System will check for ow when
system controller pump terminals are
energized. If no ow is present, it will
display 63 error code
System will not check for pump
operation*
Pump rotation Not
Available
Available Available System will rotate pump 1 and 2
operations
Pump 1 and 2 will operate
simultaneously*
*Factory Default Settings
─12─

1
2
Operation Screen Display Description
Change the way the units of temperature and ow rate are displayed on the screen (standard vs. metric).
1) In the initial settings menu
select “[°F / gal] [°C / L]”.
2) Press the button.
1) Use the buttons to select
the unit “[°F / gal] “or “[°C / L]”.
2) Press the button to set
the units to be displayed.
3) The display will say “Set complete”
once an option is chosen.
* You may use the button to
return to the previous menu at any
time.
11) Disconnect Power to all heaters and system controller in
the multi-unit system.
2) Wait 10 seconds or more.
3) Reconnect power.
After nishing the Initial Settings.
─13─

8. Recirculation Pump Timer Setup
For
Setting the Recirculation System Operation Timer
This example describes setting the recirculation system to operate between 5:00 am - 8:00 am.
1
2
3Here
1)
2)
1)
2)
(Example of a display)
1)
2)
* With the recirculation operation timer set, hot water
will be automatically circulated in the hot water pipes.
Even with this function activated, it may take several
minutes for hot water to be completely circulated
through the plumbing system. Set the timer to
activate the recirculation system prior to the first use
of hot water to ensure hot water is instantly available.
* Multiple recirculation time periods can be set.
* Until the timer is deactivated (Next Page), the
recirculation system will operate daily at the set times.
* When the recirculation system is turned “OFF” by
the timer, the water heater will still remain “ON”
and can be used normally.
* The previous setting is displayed.
* Every time when you press the
button,
the time changes by one hour.
[To keep the current “Start” time]
Press the
button
without changing
the "Start" time, and proceed to step 4.
[To add additional time periods to the current
setting, or to cancel the previous setting]
1) Press the
button
without setting "Start" time.
2) Press the
button
without setting "End" time.
3) Follow the procedures "Adding
Additional Time Periods” or
“Resetting All Time Periods” (Next Page).
Cover shown
in the open
position.
Check that the current time is properly set.
(Setting the time page 19.)
Preparation
* You can set the timer regardless if the
button is “ON” or “OFF”.
1) Select "Recirc timer"
using the buttons.
2)Press the button.
1) Press the button inside the
cover, Select "Recirc menu" using
the buttons.
2) Press the button.
1) Select "AM5:00" using
the buttons.
2) Press the button
to complete the “Start”
time setting.
Operation Screen Display Description
*This functionality is only available if you have selected
“
Recirc
”
as your system type in the
“
Initial Setting Procedure
”
and
“
System Selection and Settings
”
on page 10 to 11.
─14─

5Press the button to
complete the time settings.
4Here
1)
2)
Lit
"Recirc timer" and "Recirc timer on" are alternately
displayed on the menu (approximately 10 seconds)
(Example of home screen when the Power ON/OFF button is turned "ON")
1)
2)
* You can set multiple operation
time periods.
1)
2)
1)
2)
The screen returns to the Recirc Menu.
<Adding Additional Time Periods>
<Resetting All Time Periods>
Operation Screen Display Description
* If the button is "ON", the
screen returns to the home screen
in approximately 10 seconds.
1) Carry out steps 1 to 2.
2) Select "Cancelled"
using the buttons.
3) Press the button.
To Cancel the Recirculation System Operation Timer
* The timer will not activate without
pressing the button.
* If the time is not set, the time setting
screen is displayed.
* Until the timer is deactivated, the
recirculation system will operate
daily at the set “Start” and “End”
times.
(All settings are cleared.)
3) Adjust the time period following
the procedures in Steps 3 to 4.
1) Select "Add" using
the buttons.
2) Press the button.
3) Select the time period following
the procedures in Steps 3 to 4.
* Every time when you press the
button,
the time changes by one hour.
[To keep the current “End” time]
Press the
button
without changing
the "End" time, and proceed to step 5.
1) Select "AM8:00" using
the buttons.
2) Press the button to
complete the “End”
time setting.
1) Select "Reset" using
the buttons.
2) Press the button.
─15─

9. System Check Button
System Displayed on
the Remote Controller System Description
Water heater only operation.
* Water heater and recirculation operation.
* During recirculation operation, hot water is
always circulated in the piping to provide
instant hot water when a xture is opened.
[If you set the button to "ON",
is displayed.]
* Water heater combined with a storage tank
operation.
* If a recirculation system is also installed,
hot water is always circulated in the piping
to provide instant hot water when a xture
is opened.
[If you set the button to "ON",
is displayed.]
Cover shown in the
open position.
(Display Screen Example [System [Rcrc] ])
If you press the button, you can check the status of the system
─16─

10. Maintenance Monitors and Additional Settings
* It is necessary to check the ow rate for Recirculation system, and Storage
Tank Recirculation system (for adjusting the recirculation ow rate).
<Example of display (ºF/gal)>
Flow rate of unit 1 is 4.0 gal/min
Flow rate of unit 2 to 5 is 0 gal/min
Unit 6 is not connected
(1) Press Menu Button and press the ▼ Button several times to select "Sys monitor",
and then press Enter Button.
(2) Press the ▼ Button once to select "Yes", and then press Enter Button for ve
seconds or more.
(5) To display ow rate of Unit 7 - 12.
Press the Enter Button, the > mark changes the position from the left side of item No. to the right side of adding No.
(3) Sys monitor is displayed.
Since item 03 is displayed first, you must press the ▲/▼ Buttons several
times until item 14 is displayed.
(4) Flow rate screen is displayed.
*The unit of ow rate on the screen can be changed (refer to page 13).
<Example of display (ºC/L)>
Flow rate of unit 1 is 15.0 L/min
Flow rate of unit 2 to 5 is 0 L/min
Unit 6 is not connected
Item No.
Unit No. Unit No.
(6) Press Back Button.
(7) The screen that asks whether continue or cancel the Sys monitor is displayed.
Select "cancel" by pressing the ▼ Button to terminate the Sys monitor.
Then, press the ▲ Button, the value of adding No. changes from "+00" to "+06".
When "+06" is displayed, add six to displayed unit No.
Item No.
Unit No. Unit No.
Adding No.
Press the ▼ Button, the value of adding No. returns from "+06" to "+00".
<Example of display (ºF/gal)>
Flow rate of unit 7 is 4.0 gal/min
Flow rate of unit 8 to 11 is 0 gal/min
Unit 12 is not connected
Enter Button
▲/▼ Buttons
Back Button
Menu Butto
n
<Remote controller (RC-9018M)>
─17─

Additional settings of system controller
Following setting can be changed in addition to the system settings.
When determining whether or not to change a particular setting, please consult
with the customer rst.
Setting Procedure (example to change Item No. 1A)
(1) Turn the water heater o󰀨 by pressing the Power ON/OFF Button on the
remote controller.
(2) Turn OFF the power supply (disconnect electrical power to all heaters and
system controller), then turn ON the power supply (reconnect electrical
power to all heaters and system controller) and wait 10 seconds before
proceeding to step (3).
(3) Within the rst ten minutes of connecting electrical power, before turning
on the Power ON/OFF Button, press the ▲/▼ Buttons on the remote
controller and hold until the display blinks "99". If "99" does not blink on the
remote controller, disconnect electrical power to all heaters and system
controller and try again.
(4) Use the ▲/▼ Buttons on the remote controller to scroll to the item number
"1A" on the column of the item.
(5) Press the ENTER Button, "Item number" stops blinking and "Data state
(OFF or ON)" will start blink.
Use the ▲/▼ Buttons on the remote controller to change OFF ←→ ON.
(6) Change "1A" from OFF to ON.
* Do not adjust any other items!
(7) When the items has been set correctly, press the ENTER Button, "Data
state (ON)" stops blinking and "Item number" will start blink. Conrm the
setting by pressing and holding both the ▲/▼ Buttons on the remote
controller until the controller emits a beeping noise.
The new setting will be lost if this is not done.
(8) Disconnect Power to all heaters and system controller in the multi-unit system.
Wait 10 seconds or more, and reconnect power.
- Item No. 1A
By factory default, the remote controller alarm will sound when a failure of the
system controller or any water heater in the system has occurred.
However, this setting can be changed so that the alarm sounds only when the
entire system is down.
- Item No. 19
When multiple units are connected to the system controller, two units fire
upon startup as the factory default.
However, this setting can be changed so that only one unit res upon startup.
List of settings
Item # Data indication
19 OFF (Two units re at startup)* ON (One unit res at startup)
1A OFF (Alarm for any system error)* ON (Alarm only for system down error)
* Factory Default Settings
Power ON/OFF Button
▲/▼ Buttons
Enter Button
<Remote controller (RC-9018M)>
─18─

11. Additional Remote features
For All Systems
Clock Adjustment
* This adjustment can be made
regardless of whether the
button is ON/OFF.
1
2
(Ex: 10:15 am)
Cover shown in
the open position.
31)
2)
The screen returns to the previous screen.
Press the button
inside the cover.
Press the button.
1) Use the buttons to
adjust the clock.
2) Press the button
to complete the clock setting.
* The time changes in 1-minute
increments with each press
of the button, and then in
10-minute increments if the
button is kept pressed down.
* If the display is left untouched for
approximately 20 seconds without
pressing the button, the
setting will be completed. When
the button is turned ON, the
home screen will be restored.
* In the event of a power outage or after disconnecting power to the water heater, when power is
restored, the clock on the display screen will show " - : - - " and the clock will need to be reset.
Operation Screen Display Description
─19─

For All Systems
Locking the Remote Controller
* Approximately 3 seconds after
the "locked" screen appears,
the display will return to
the previous screen.
1
By locking the remote controller, the
settings cannot be accidentally changed
if a button is pressed by mistake.
Press and hold button
for approximately
2 seconds to lock the
remote controller.
* The operation can be locked
regardless if the button is
“ON” or “OFF”.
* The operations of , ,
and buttons are locked.
* Approximately 3 seconds after
locking
the remote controller, the display will
return to the previous screen.
If you press these buttons
* Approximately 3 seconds after unlocking
the remote controller, the display will
return to the previous screen.
To Unlock the Remote Controller
Press and hold button
for approximately
2 seconds to unlock the
remote controller.
Cover shown in
the open position.
Operation Screen Display Description
while the remote controller
is locked, the “Locked”
screen will appear.
─20─