Replacement Of Parts; Replacement Procedure; Components Replacement Instructions; Pcb - Navien NCB-180 Service Manual

6. Replacement of Parts

6.1 Replacement Procedure

CAUTION
1. When performing maintenance and/or servicing the
boiler, always turn off the electric power, gas and
water shut-off valve. Wait for the boiler to become
cool. Be careful to avoid injury to your fingers on sharp
edges.
2. Drain all water from the boiler when removing the
waterway components.
3. Before any disassembly, make sure that all issues and
error codes are properly diagnosed.
4. Handle all parts carefully.
5. When reassembling, prevent any foreign substance,
i.e. dust, etc. from entering back into the boiler.
6. After reassembling, check for gas and water leakage.
Then, test for proper ignition. Make sure that there is
no gas leakage from the gas connections by testing
with soap bubble solution. Bubbles indicate a gas leak
that must be corrected.
7. Check the performance and operation after the boiler
has been serviced.
To remove and replace any parts from the boiler, you will
need a screwdriver that is at least 8 ~ 10 inches long. A
flashlight and magnetic tip are also recommended. Navien
recommends the use of a parts tray to hold small parts and
screws. All of the hardware is essential to the proper
operation of the unit upon re-assembly.
NOTE
When disassembling and reassembling the boiler, refer
the components diagram & parts list.
6.2 Components Replacement
Instructions

6.2.1 PCB

1. Turn off the gas supply to the unit.
2. Disconnect the unit from the power supply.
3. Turn off the water supply to the unit.
4. Disconnect wiring connector from the Front Panel.
Figure 1
5. Disconnect all wiring connectors from the PCB
Figure 2
6. Remove the 3 screws from bottom PCB bracket and
upper PCB bracket.