Navien NCB300-28K Installation & Operation Manual page 50

10.1.2 Buttons
Using the buttons on the front panel, you can turn on or off the boiler,
monitor the current operation status, and set the values required
for the boiler's operation, such as central heating and DHW supply
temperatures. Refer to the following table for detailed information.
a
c
e
Menu button
Access to the Main menu screen.
Eco button
Turn the boiler DHW preheat on or
off.
Info button
Access the boiler information.
a
b
c
Plus button
b
Increases the temperature setting,
parameter or moves up.
Minus button
d
Decreases the temperature setting,
parameter or moves down.
Power button
f
Turns the boiler on or off.
Reset the boiler during an error.
d
e
f
Operating the Boiler 49