Navien NCB300-28K Service Manual page 80

5.2.14 Error 515
Error occurrence conditions and check items
Error
E515 error
Check items
Check the sub code
number of E515
Number 1,2 or 10
Check the wire connection
between gas controller and Main
PCB. Check the coil of solenoid
valve.
1. Turn off and on the Power
RESET switch.
2. In that same case, replace the
Main PCB.
Check Method
Fault
PCB or Electrical supply
If an error occurs in the internal circuit of the PCB (e.g., resistance, transistor or relay fault),
the system displays 515E (cleared manually) on the PCB.
1. Defective PCB
2. Check with a multimeter if the PCB is supplied with the proper voltage (AC 230 V).
3. Check the wire connection.
4. Disconnect the ground wire, then check the PCB.
Number 3 or 4
Possible Causes
Defective PCB Replace the PCB if there is an error with the PCB internal circuit.
Check with a multi-meter if the PCB is supplied with the proper voltage.
Power supply error
●
Power supply grounding noise causes malfunction.
Power supply grounding
●
noise
Description
Number 9
Check the Fan voltage.
Check with a multi-meter if the voltage at the electrical outlet is AC 230 V.
Disconnect ground from the grounding terminal inside the unit, and check
if the PCB is operating normally.
Number 11 or 12
1. Check the wire connection
between dual venturi and Main
controller.
2. Check the dual venturi.
Check method
Troubleshooting 79