Navien NP-180 Service Manual page 155

13. Replace the O-ring (in service parts)
included the 3-way valve.
14. Replace with new pump.
15. Connect 3-way valve and secure with
stainless clip.
16. Tighten the screw from the 3-way valve
and tighten screws bottom base.
17. Tighten the screw from pump bracket.
18. Reseat the non-threaded end of pump into
the copper (stainless) fitting. At this time,
be watchful the red gasket ring.
19. Close the drain plug and tighten screws
from bottom base
20. Replace the PCB. (refer to 8.2.1 PCB)
21. Install front panel using 4(four) screws.
22. Turn on water supply, power supply, and
gas supply.
23. Open a hot water tap and ensure there are
no leaks at the water heater.
24. Open air vent on top of pump to release
air.
NOTE
1. Always use right part(O-ring) and right size
and place to pipe
2. Place red gasket ring on top of the
circulation pump and screw on the brass
(stainless) nut; be sure not to cross thread;
over tightening may damage gasket.
©Navien America Inc. 2010
153
NR/NP series service Manual Version 2.0