Navien NPE-180A Service Manual page 147

6. Remove the pump inlet filter from the bottom of the water
heater.
Pump Inlet Filter
Pump Drain Plug
7. Open the pump drain plug.
8. Remove the cold water inlet filter.
9. Allow the residual water to drain from the water heater.
10. When the water is completely drained, reinsert the pump inlet
filter and the cold water inlet filter, and then close the pump
drain plug.
11. To refill the water heater follow the steps of "Draining the
Water Heater" in reverse.
146 NPE Service Manual
Draining the water in the condensate trap
Referring to the below figures, place a bucket under the water
heater and remove the cap from the bottom of the trap to drain
collected condensate.
Cold Water
Inlet Filter
#
1
2
3
4
5
6
1 2 3 4 5 6
Description
Remove the retaining clip.
Place a bucket under the water heater.
Twist and remove the cap.
Clean out the condensate trap.
Replace the cap and the retaining clip.
Pour water down the exhaust flue (if possible) or
allow the unit to run to refill the condensate trap.
Version 2.21