5) When using Remote Controller RC-9018M, refer to step 6) to 11) procedure below.
When using Remote Controller RC-7649M, follow instructions on pages 22 - 26.
Then proceed directly to step 10).
6) In approximately 10 seconds, the system settings screen (Figure 3) is displayed on the Remote Controller.
Set up initial setting in accordance with the screen.
* Refer to page 10 - 11 for some parameter settings.
7) If necessary, set the miscellaneous system selection.
*Refer to pages 11 - 13 and 18.
8) Set the clock* of the remote controller.
*Refer to page 19 for setting the clock.
9) If you want to set the recirculation system operation timer, refer to pages 14 - 15.
* This timer is only available for the recirculation system.
10) Reconnect any options
(e.g. Warning Light, Operation Light, Circulation Pump, Exhaust Fan) disconnected from step 1).
11) The replacement is complete.
20. Procedure for replacing Sub Controller in the System Controller
This manual is intended to provide instruction fot the replacement procedure of the Sub Controller in the System
Controller (SCU-401).
Refer to the "Procedure for replacing Main Controller in the System Controller" for Main Controller(SCU-401).
Before replacing the System Controller, be sure to read this sheet and System Controller Installation Manual for
correct operation.
1) Verify if any options (e.g. Warning Light, Operation Light, Circulation Pump, Exhaust Fan) are utilized.
If in use, disconnect the electric power for all options being used.
2) Turn off the Power ON/OFF Button first, then disconnect the electrical power for SCU-401 and all water heaters.
3) Replace the Sub Controller of System Controller.
1. Remove the screw (
1
in Figure 2).
2. Disconnect all wires from the Sub Controller of System Controller.
3. Install the new Sub Controller into the System Controller and reconnect all wires and connectors to the new Sub
Controller.
4. Secure the screw (
1
in Figure 2) again.
4) Connect the electric power for SCU-401 and all water heaters, and then turn on the Power ON/OFF Button.
5) Reconnect any options
(e.g. Warning Light, Operation Light, Circulation Pump, Exhaust Fan) disconnected from step 1).
6) The replacement is complete.
Main Controller
Figure 1: SCU-401-24M
Figure 2: Main Controller and Sub Controller
1 Screw
SCU-401-24M Only.
Sub Controller
Introduction
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