Navien NCB-700-2S+/42K Service Manual page 41

Item
1. Fan Motor
2. Circ Pump (Heating)
3. 3 Way Valve
4. Dual Venturi
5. Flow control Valve
6. Mixing Valve
7. Recirc Pump (DHW)
40 System Details
Description
Test the fan operation.
From a stopped state, the fan
speed gradually increases and
reaches the maximum speed
at 6500 RPM, and then the fan
speed decreases until the fan
stops operating.
Except for the Power
Note
button ( ), the
buttons do not work
during fan motor test
mode.
Test the boiler pump operation.
On (10 seconds) -> Off (5 seconds)
-> On (10 seconds) for 5 boiler
pump operation cycles
Except for the Power
Note
button ( ), the
buttons do not work
during boiler pump
test mode.
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. 1st MIN
3. 1st MAX
4. CH 2nd MAX
5. DHW 2nd MAX
6. 2nd MIN
) simultaneously for
) to switch
) to
Description
Set the boiler to run in normal
operation mode.
Set the boiler to run in 1st stage
minimum operation mode.
Set the boiler to run in 1st stage
maximum operation mode.
Set the boiler to run in 2nd
stage central heating maximum
operation mode.
Set the boiler to run in
2nd stage DHW maximum
operation mode.
Set the boiler to run in 2nd
stage minimum operation
mode.