Navien NFC-175, Service Manual

Page: 123 / 138

NFC Service Manual 123 Version 1.0
8. Remove the 6 screws from Intake Pipe and Venturi.
Figure 8
Figure 9
9. Replace Fan Ass’y to the original position and reconnect the
wiring connector from the Fan and Venturi.
10. Turn on water supply, power supply, and gas supply to the
unit.
Note
Do not over-tighten the screws for the fan motor
replacement with high torque drill. This may cause
damage to the part(s).
6.2.4 Flame Rod
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. Remove the Ignition Transformer insulated cables.
5. Remove the 4 screws from the flame rod as shown in Figure
below.
Figure 10
6. Remove the flame rod wiring connector.
7. Remove the flame rod from the burner assembly and replace
with the new part.
8. Reconnect the 2 ignition transformer insulated cables to the
new flame rod.
9. Place the new flame rod back onto the burner assembly and
secure it by using the 2 screws from Figure .
10. Turn on water supply, power supply, and gas supply to the
unit.
Note
Always use new factory gaskets included with the flame
rod when replacing the part onto the burner assembly.
6.2.5 Ignition Transformer
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. Remove the Ignition Transformer insulated cables from the
igniter probe connectors.