Navien NCB-180, Service Manual

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92 NCB Service Manual Version 1.0
5.2.5 030Error
Error occurrence conditions and check items
Error Description
E030
Exhaust gas
temperature error
If the overheat controller on the top of the exhaust duct is initiated, the system displays the heat exchanger
bimetal overheat message 030E (cleared manually) on the front panel.
The boiler switches into Lock-Out, and performs post-purge continuously and operates the pump.
Overheating controller operates when the temperature exceeds 230°F (110°C) for 10 minutes or over.
1. When the controller detects the exceeding temperature of 230°F (110°C) for 10 minutes or over, "E030"
error code will display and perform post-purge.
→
Automatically cleared.
2. When the controller detects the exceeding temperature of 140°F (60°C) while performing post-purge.
→
Manually cleared.
3. When the controller detects the exceeding temperature of 230°F (110°C) for 10 seconds or over three
times or more after the error is automatically cleared.
→
Manually cleared.
Check items
1. Check if the overheat controller operates normally.
2. Check if the PCB works properly.
Is exhaust thermistor
normally operating?
Check the resistance between #9 and #10 of CN 13:
short-circuit (check page 51 for Wiring Diagram)
Check the exhaust thermistor
Check the heat exchanger
Check for leakage in the
combustion chamber
Flush heat exchanger
NO
Yes