Navien CH-180, Service Manual, Page: 69 / 155

67
Adjust gas
pressure
PCB DIP S /W
model setting
error
Check if
there is any
debris in the
nozzle.
Adjust differential pressure to MIN between 3 stages with the gas
manometer (17
̀ H Њ O±1). Ą refer to 6.2.2 Adjusting the Gas-Air
Ratio
Turn the adjusting screw under the gas block ½ turn and
restart.
When an ignition failure occurs due to a problem in supplying
gas or adjusting gas pressure, cover the blower inlet hole with
a hand at the ignition stage. If a flame occurs, check the gas
supply system.
Incorrect DIP S/W setting per model on the PCB may cause a
problem on ignition and combustion.
Ignition failure occurs if there is debris in the nozzle.
Disassemble the manifold and check the nozzle (Stage 1).
<Defective APS hose>
<Check the differen-tial gas pressure>
<Adjust gas pressure at Min>
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0