Error - Navien NCB-700-2S+/42K Service Manual

5.2.4 Error 012

Error Conditions and Checklist
Error
If the system detects a loss of flame during combustion, the system stops the gas supply and attempts to restart.
E012
Then, the system adds the instance to the flame loss count. If flame loss occurs 20 times consecutively, error code
Loss of flame
012E is displayed (manually cleared) on the front panel.
1. Use a manometer to measure the gas supply pressure (NG: 17-25 mbar, LP: 25-35 mbar)
2. Check the gas meter rating.
3. Tighten the ground connection screws on the heat exchanger.
Checklist
* Test the resistance of flame detection AD to confirm it is correct.
4. Check if the gas orifice is obstructed.
5. Check if the PCB is working correctly.
74 Troubleshooting
Is the boiler's supply gas
pressure correct?
Yes
Check the connections
Description
No
Test the gas pressure
Gas pressure
Natural Gas: 17-25 mbar
LP Gas: 25-35 mbar