Navien CH-180, Service Manual, Page: 133 / 155

© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0
8.2.12. Flow Sensor
7. Loosen the domestic cold water inlet
adaptor 2 screws.
1. Turn off the gas supply
2. Turn off the 120V power supply
3. Turn off the water supply. Drain all
water from the appliance.
4. Remove the four screws securing
the front panel. Remove front panel.
5. Pull out the PCB. (refer to 8.2.1
PCB)
6. Remove the fastener “C” and the
heating water inlet pipe . 8. Remove the fastener “A” and water
flow sensor from bottom base ,
domestic hot water exchanger.
9. Replace the Oring (in service parts)
included remove parts.
10. Reseat the water flow sensor from
the domestic cold water inlet adap
tor and domestic hot water
exchanger.
11. Replace the fastener “A”.
12. Tighten the cold water inlet adaptor
2 screw.
13. Replace the heating water inlet
pipe and fastener “C”.
14. Replace the PCB. (refer to 8.2.1
PCB)
15. Install front panel using 4(four)
screws.
131
Figure 32
Figure 34
Figure 35
Figure 33