Package Unit: D2NP
Re: Code 2
CODE 2 = Pressure switch "Open" with the inducer motor energized.
||Bad Inducer Motor
||Bad Pressure Switch
||Clogged Pressure Port
||Item Stuck in Inducer Wheel
||Bad Ignition Control Board
1. Check Heating Sequence
- Energize a call for heat from the thermostat.
- Ensure that the inducer motor starts.
2. Check Control Board
- Check for 24VAC between "W' and "C" on the ICB.
- No Power on "W" = No Call for Heat
- 1-Stage Heat Models
- Check for 230VAC between Ignition Control Board [IND] terminal (BLK) and Compressor Contactor L2 (PRP).
- 2-Stage Heat Models
- Check for 230VAC between Ignition Control Board [IND] terminal (RED) and Compressor Contactor L2 (PRP).
- Also, check for 230VAC between Ignition Control Board [H-IND] terminal (BLK) and Compressor Contactor L2 (PRP).
3. Check Inducer
- Check the temperature of the inducer motor.
- Use an Amp Probe to check the amperage of the inducer motor.
- 230V Power + Hot Motor + No Amperage = Off on Overload ⇒ Turn off power to the unit, allow motor to cool, then recheck.
- 230V Power + Cool Motor + No Amperage = Bad Inducer Motor
- 230V Power + Amperage + Not Running = Bad Inducer Motor or Item Stuck in Inducer Wheel ⇒ Remove Inducer Assembly & Check Wheel
4. Check Pressure Switch
- Check for 24VAC between "C" of the Ignition Control Board and 245/PRP on the pressure switch.
- Power + Code 2 = Bad Ignition Control Board
- No Power = Open Pressure Switch
- Use a pressure gauge to check the negative pressure from the inducer.
- Adequate Negative Pressure = Bad Pressure Switch
- No or Low Negative Pressure ⇒ Remove the inducer assembly, check the condition of the Blower Wheel and look for a Clogged Pressure Port