Navien NP Condensing Tankless Gas Water Heater - Service Manual

8.2.14. Buffer Tank (“A” Series)
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. Loosen the PCB 2 screw from bottom base.
5. Pull out the fan. (refer to 8.2.5 Fan motor)
6. Remove the fastener “A” (A) and fastener
“F” (B).
8. Pull out the buffer tank.
9. Replace the Oring. (in service parts)
included the copper (stainless) pipe.
10. Replace the Oring (in service parts)
included the buffer tank.
11. Reseat the buffer tank from the cop-per
(stainless) pipe and plastic adapter.
12. Replace the fastener “A” (A) and fastener
“F” (B).
13. Tighten the 4 buffer tank screws.
14. Replace the fan (refer to 8.2.5 Fan motor)
15. Install front panel using 4(four) screws.
16. Turn on water supply, power supply, and
gas supply.
17. Open a hot water tap and ensure there are
no leaks at the water heater.
< Figure 37 >
7. Loosen the 4 buffer tank screws.
NOTE
1. When draining, using caution with high
water temperature in tank.
2. Use right size of Oring.
3. When draining, use caution not to wet
electrical components.
< Figure 38 >
©Navien America Inc. 2010
151
NR/NP series service Manual
Version 2.0