Dhw Heat Exchanger; Expansion Tank - Navien NCB-24LSWE Service Manual

6.2.13 DHW Heat exchanger

1. Turn off the gas supply to the unit.
2. Turn off the 230V power supply to the unit.
3. Turn off the water supply to the unit. Drain all water
from the appliance.
4. Remove the gas supply unit.
5. Remove the two screws at the DHW exchanger.
Figure 16
6. Replace with the new DHW Exchanger.
130 NCB Service Manual

6.2.14 Expansion tank

1. Turn off the gas supply to the unit.
2. Turn off the 230V power supply to the unit.
3. Turn off the water supply to the unit. Drain all water
from the appliance.
4. Disconnect the expansion tank connection from the
bottom of the boiler.
5. Remove the four bolts from the top of the boiler.
6. Replace the old expansion tank with a new one.
7. Install the 4 bolts and reverse the steps to re-connect
the connections and operate the boiler.
Version 1.0