Navien NHB-055, Service Manual

Page: 92 / 147

92 NHB Service Manual Version 1.0
5.2.4 012Error
Error occurrence conditions and check items
Error Description
E012
Flame loss
If the system detects loss of flame during combustion, the system stops supplying fuel,
attempts to restart, counts the incidents of flame loss, and if the incident occurs 20 times
consecutively displays 012E (manually cleared) on the front panel.
Check items
1. Measure, with a manometer the gas supply pressure (NG: 3.5” ~ 10.5” W.C, LP: 8”~ 13.5” W.C)
2. Check the Gas meter Capacity.
3. Tighten the ground connection screws on heat exchanger.
4. Check if the gas orifice is clogged.
5. Check if the PCB is working properly.
6. Check the offset of the gas control valve and CO2.
Does the boiler have
sufficient gas pressure?
Check connector
(#1 of CON22)
See page 63-64 for Wiring Diagram.
Check the gas pressure
Gas Pressure
Natural Gas: 3.5” - 10.5” W.C.
LP Gas: 8.0” - 13.5” W.C.
No
Yes