Dhw Heat Exchanger - Navien NCB300-28K Service Manual

5. Remove the clip on the WPS valve.
6. Replace with new water pressure sensor.
7. Connect the water pressure senor wire housing.
Always use proper O-rings at the water pressure
Note
valve connection to ensure tight seals.
92 Replacement of Parts
Figure 19

6.2.12 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 20
6. Replace with the new DHW Exchanger.