Navien NCB300-28K, Service Manual

Page: 89 / 108

88 Replacement of Parts
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
flame rod.
5. Refer to figure 9 and disconnect the wiring connector from
the Ignition Transformer.
Figure 9
6. Remove the screw from the Igniter Transformer.
Figure 10
7. Pull out the Ignition Transformer.
8. Replace the old Ignition Transformer with the new part, and
then use the two screws to secure the part.
9. Reconnect the Ignition Transformer insulated cables to the
flame rod.
10. Reattach the wiring connectors from the Ignition
Transformer.
11. Turn on water supply, power supply, and gas supply to the
unit.
Note
Verify that the Ignition Transformer insulated cables
are firmly connected to the flame rod.
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 two screws from the flame rod as shown in
figure 7 below.
Figure 7
6. Remove the flame rod wiring connector.
Figure 8
7. Remove the flame rod from the burner assembly and
replace with the new part.
8. Reconnect the two 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 two screws from figure 7.
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.