Navien NP-180 Service Manual page 122

Check the connection of wire to wire
connector between bypass mixing
valve and PCB
Check the connection of
wire to wire connector between
bypass mixing valve
and PCB
Dose Mixing trans have
normal output voltage?
Check operation voltage
and pulse from PCB
Replace PCB
©Navien America Inc. 2010
Yes
*operation checking: supply power, turn R/C on/off,
No
No
Yes
Yes
No
120
NR/NP series service Manual
Try Restarting
stop the burner operation
Replace Mixing trans
Check the voltage between blue and
blue wire of CN23 : 14 ~20 VAC
Replace Bypass Mixing Valve
Check the voltage and pulse of CN24
BLACK-RED : DC 7~13 V
BLACK-WHITE : DC 0~13 V
PINK-ORANGE : -12 ~ 12 VDC (pulse)
BLUE-YELLOW : -12 ~ 12 VDC (pulse)
Version 2.0