Navien NP-180 Service Manual page 74

Proportional
valve
Adjusting screw
<Gas block>
Flame sensing
Repeated ig-
nition-out
Defective air
pressure hose
Air pressur
Flame blo-wout
and
noise occurs
at ignition
©Navien America Inc. 2010
Solenoid
valve
<Check if the coil is open>
1. Check the location of the flame detecting rod, if there is any
deformation or foreign substance, and repair or replace the part.
2. Check the sheath of the fire detecting wire, and if it is open.
3. Check the grounding to the base, verify grounding at the outlet.
There is a case of defective grounding due to the painting of exterior
error
base. Therefore, remove the painting in the screw fastening part,
and reconnect.
Or use a tester to measure the flame sensing current.
(normally 3~4 μA)
< Grounding wire
fixing position >
1. The air pressure hose is broken.
Increased RPM may cause blowout and noise.
2. 10E may occur with the same trouble.
The system works but combustion is not normal due to the defective
sensor air pressure sensor.
< Defective air pressure hose >
72
NR/NP series service Manual
<Check the voltage of the
solenoid valve / Brown 2P>
< Measuring flame current >
Version 2.0