Navien CH-180, Service Manual, Page: 139 / 155

© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0
8.2.18. Domestic Hot Water Exchanger
1. Turn off the gas supply.
2. Turn off the 120V power supply.
3. Turn off the water supply. Drain all
water(include heating 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. Pull out the flow sensor. (refer to
8.2.12 Flow Sensor.)
7. Pull out the domestic hot water outlet
collar. (refer to 8.2.19 DHW outlet
collar)
8. Remove the stainless clip. (fastener
“A”)
9. Remove the stainless clip. 10. Pull out the domestic hot water
exchanger.
11. Replace the new domestic hot
water exchanger.
12. Replace the 2 stainless clip.
13. Replace the domestic hot water
outlet collar.
14. Replace the water flow sensor.
15. Replace the domestic hot water
outlet collar.
16. Install front panel using 4(four)
screws.
17. Turn on water supply, power
supply, and gas supply.
18. Open a hot water tap and ensure
there are no leaks at the boiler.
137
Figure 50
Figure 49
G