Navien NP-180 Service Manual page 72

Check method
Error type
Gas supply error
Ignition fail
< Check gas supply pressure >
Defective electrode
gap and shape
©Navien America Inc. 2010
Cause
1. Check if the main gas valve is open.
2. Check the gas supply pressure.
NG: 5"(6" 180 MODEL) ~10.5" W.C, LP: 8"~13.5" W.C
LP pressure drop occurs frequently in the winter.
3. Check the flexible pipe dia. (20mm)
4. While the static pressure is normal, a large difference of dynamic
pressure may cause drop of gas pressure. Therefore, it is required to
check the dynamic pressure.
Static pressure: Gas pressure at the stop of the boiler.
Dynamic pressure: Gas pressure at boiler max combustion.
(3rd stage MAX combustion setting: DIP S/W1-1 ON)
5. Excessive force in fastening nuts at installation of gas pipe may
move the packing and block the Teflon sealing, causing a drop of
gas supply pressure.
6. Check the meter class (Example)
Gas meter Water heater
425 CFH ≥ 195 CFH + 58.8 CFH + 63.7 CFH
* 1 CFH = 1,020 Btuh
Defective electrode gap and shape disables ignition.
Appropriate electrode gap: approx. 3~4mm (replace if defective)
An ignition fail may occur due to improper gap, while discharge
seems normal when checked via the flame monitoring window.
Therefore, it is required to check the gap after disassembly.
NR/NP series service Manual
Check method
Domestic gas stove
Furnace
< Moved packing narrows the inner diameter >
70
Version 2.0