Navien NP-180 Service Manual page 71

Scenario 3
Is gas valve normally
operating?
Yes
Check the flame rod
©Navien America Inc. 2010
Does the main gas valve
No
have proper voltage?
Yes
Does the main gas valve
have proper resistance?
Yes
Does the modulating gas
valve have proper
voltage?
Yes
Is the tube which is
connected with modulating
gas valve properly
installed?
Yes
Check the burner assembly
69
NR/NP series service Manual
No Check connector
Check the voltage between two brown
wires (1-2) of CN 15: 83 -120VDC
No Replace gas valve assembly
Check the resistance between two brown
wires
(1-2) of CN 15: 0.8 -2.4k ohm
No Check connector
Check the voltage between two wires of
CN 14 : 2 -10VDC
No Check tube
Version 2.0