030Error - Navien NFC-175 Service Manual

5.2.6 030Error

Error occurrence conditions and check items
Error
E030
Exhaust gas temperature error
Check items
86 NFC Service Manual
If the temperature sensor on the bottom right of the exhaust duct is initiated, the system
displays the exhaust 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.
2. When the controller detects the exceeding temperature of 140°F (60°C) while performing
post-purge.
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.
1. Check if the overheat controller operates normally.
2. Check if the PCB works properly.
Is exhaust thermistor
normally operating?
Yes
Check the heat exchanger
Check for leakage in the
combustion chamber
Flush heat exchanger
Description
→ Manually cleared.
No
Check the exhaust thermistor
Check the resistance between #1 and #2 of
CNJ1: short-circuit (See page 50-51 for
Wiring Diagram)
→ Automatically cleared.
→ Manually cleared.
Version 1.0