Navien NFC-175, Service Manual

Page: 48 / 138

48 NFC Service Manual
Version 1.0
4.9.7 Setting the Special Operation Modes
To operate the boiler in special operation modes, press the Back
button ( ) and the Menu button ( ) simultaneously for
3 seconds, and then select “7. Special Operations”.
Rotate the Command dial ( ) to switch between the operation
modes. Press the Command dial ( ) to select an operation mode.
The boiler resumes operation in normal operation mode if no input
is detected for 3 hours.
Press the Back button ( ) to return to the previous screen or
menu.
Item Description
1. Normal
Set the boiler to run in Normal
operation mode.
2. 1st MIN
Set the boiler to run in 1st stage
minimum operation mode.
3. DHW 1st MAX
Set the boiler to run in DHW 1st
maximum operation mode.
4. 2nd MIN
Set the boiler to run in 2nd stage
minimum operation mode.
5. DHW 2nd MAX
Set the boiler to run in DHW 2nd
maximum operation mode.
6. SH 1st MAX
Set the boiler to run in SH 1st maximum
operation mode.
7. SH 2nd MAX
Set the boiler to run in SH 2nd
maximum operation mode.
Item Description
4. Zone 2 Pump
Test the zone 2 pump operation.
●
The zone 2 pump is turned on as
soon as you enter the test mode.
●
Press the Command dial ( ) to
toggle the pump operation (On ->
Off / Off -> On).
●
This option is available only when
the “Zone Pump System” is active.
5. Zone 3 Pump
Test the Zone 3 pump operation.
●
The Zone 3 pump is turned on as
soon as you enter the test mode.
●
Press the Command dial ( ) to
toggle the pump operation (On ->
Off / Off -> On).
6. 3 Way Valve Output
Test the 3 Way valve operation.
●
The 3 Way valve is turned on as soon
as you enter the test mode.
●
Press the Command dial ( ) to
toggle the valve operation (On -> Off
/ Off -> On).
7. Flow Control Valve
Output
Test the Flow control valve operation.
Rotate the valve from its current
position to fully open (0%), then fully
closed (100%) and then back to the
starting position while checking
feedback.
●
Display of the valve close ratio %
●
Display of “FEEDBACK” when
detecting the feedback
8. Mixing Valve
Output
Test the Mixing valve operation. Rotate
the valve from its current position
to fully open (0%), then fully closed
(100%) and then back to the starting
position while checking feedback.
●
Display of the valve close ratio %
●
Display of “FEEDBACK” when
detecting the feedback
9. Dual Venturi
Test the dual venturi operation.
●
The dual venturi is turned on as soon
as you enter the test mode.
●
Press the Command dial ( ) to
toggle the dual venturi operation (On
-> Off / Off -> On).
10. Recirc. Pump
Test the recirculation pump.
●
The recirculation pump is turned on
as soon as you enter the test mode.
●
Press the Command dial ( ) to
toggle the recirculation pump (On ->
Off / Off -> On).