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

4.7.4 Fan Motor

Item
Function
Fault
Symptoms
Error codes
Diagnostics
Testing/inspection
information
46 System Details
Supplies combustion air for the burner and purges exhaust flue gas.
To maintain gas input over long flue runs, the fan use APS to provide ideal combustion levels.
1. Fan speed failure: When fan speed is approximately 0 rpm.
2. A fan assembly screw is loose and/or the fan is disassembled.
3. Disconnected or defective fan connection terminal assembly.
1. Erratic combustion.
2. Vibration and noise coming from the boiler.
3. The boiler does not operate correctly.
E109, E110
1. Visual inspection: check the fan's wiring connections and mounting.
2. Voltage test: Test the fan voltage for the specified voltage shown below.
Black - Yellow: DC 340 V
Description