Navien NCB500-2S/37K Service Manual page 38

Item
3. 3 Way Valve
4. Dual Venturi
5. Flow control Valve
6. Mixing Valve
7. Recirc Pump (DHW)
Description
Test the 3 way valve operation.
The 3 way valve is turned on
●
as soon as you enter the test
mode.
Press the OK button ( ) to
●
toggle the valve operation
[On (DHW) -> Off (CH)/Off
(CH) -> On (DHW)].
Test the dual venturi operation.
Press the OK button ( )
to toggle the dual venturi
operation [On (DHW) -> Off (CH)
-> On (DHW)].
Test the flow control valve
operation. Rotate the valve
from its current position to fully
(0%), then fully closed (100%)
and then back to the stating
position.
Test the mixing valve operation.
Rotate the valve from its current
position to fully (0%), then fully
closed (100%) and then back to
the stating position.
Test the recirculation pump
(DHW) operation. Press the
OK button ( ) to toggle the
pump operation [On -> Off ->
On].
4.4.8.5 Setting the Special Operation Modes
To operate the boiler in special operation modes, press the Back
button ( ) and the Menu button (
3 seconds, and then select "5. Special Operations".
Press the Up button ( ) or the Down button (
between the operation modes. Press the OK button (
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
1. Normal
2. MIN
3. CH MAX
4. DHW MAX
) simultaneously for
) to switch
) to
Description
Set the boiler to run in normal
operation mode.
Set the boiler to run in
minimum operation mode.
Set the boiler to run in central
heating maximum operation
mode.
Set the boiler to run in DHW
maximum operation mode.
System Details 37