Water Pressure Sensor; Space Heating Strainer - Navien NCB-180 Service Manual

6. Remove the two screws on the bottom of case.
Figure 26

6.2.12 Water Pressure Sensor

1. Turn off the gas supply to the unit.
2. Turn off the 120V power supply to the unit.
3. Turn off the water supply to the unit. Drain all water
from the appliance.
4. Disconnect the water pressure sensor wire housing.
Figure 27
5. Pull out the water pressure sensor.
6. Replace with new water pressure sensor.
7. Connect the water pressure senor wire housing.
NOTE
Always use proper O-rings at the water pressure valve
connection to ensure tight seals

6.2.13 Space Heating Strainer

(Filter Cleaning or Strainer Replacement)
1. Turn off the gas supply to the unit.
2. Turn off the 120V power supply to the unit.
3. Turn off the water supply to the unit. Drain all water
from the appliance.
4. Remove the stainless pin from the space heating strainer
body.
Figure 28
5. Pull out the space heating strainer.
Figure 29
6. Replace with new strainer filter.