Navien CH-180, Service Manual, Page: 72 / 155

7 0
Check method
Error type Cause Check method
Replace the main gas valve if flame occurs before combustion or
if there is remaining flame after combustion is stopped.
Flame
before/after
combustion
Leakage from
main gas valve
Discharge
of electric-
ity from
electrode
Gas block
Defective
PCB
Thudding
noise
caused by
minimum
flow
Other
trouble
Gas may leak as the gas block is pushed by the gas supply over
the standard pressure.
Check the supply pressure - NG:6 ~ 10.5 inch WC
If the gas pressure is too high, transfer the problem to the gas
oriffice, and replace the main gas valve.
If gas leaks, close the main gas valve and repair the unit before
using the system.
Spark discharges from electrode to flame rod at ignition.
Replace or correct location of flame rod.
If the trouble continues despite the checking of above items,
replace the PCB.
© Navien Ameri c a I n c . 20 1 0 CH series servi c e Manua l Version 1 .0