Package Unit: DNZ
Re: Flashing Code 2
These units have one control board (EMCB) which controls all unit functions.
► Any heating diagnostics will be displayed on the EMCB.
CODE 2 = Pressure switch "Open" with the inducer motor energized.
Qty |
Possible Causes: |
1 |
Bad Inducer Motor |
|
Bad Pressure Switch |
5 |
Clogged Pressure Port |
|
Item Stuck in Inducer Wheel |
|
Bad Control Board |
CHECKOUT:
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 "W1" and "C" on the EMCB.
- No Power on "W1" = No Call for Heat
- 1-Stage Inducer
- Check for 230VAC between Ignition Control Board [IND] terminal (BLK) and Compressor Contactor L2 (PRP).
- 2-Stage Inducer
- Check for 230VAC between Ignition Control Board [IND] terminal (RED) and Compressor Contactor L2 (WHT).
- Check for 230VAC between Ignition Control Board [H-IND] terminal (BLK) and Compressor Contactor L2 (WHT).
3. Check Inducer Motor
- Check the temperature of the inducer motor.
- Use an Amp Probe to check the amperage of the inducer motor.
- Power + Hot Motor + No Amperage = Off on Overload ⇒ Turn off power to the unit, allow motor to cool, then recheck.
- Power + Cool Motor + No Amperage = Bad Inducer Motor
- 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 EMCB and 245/PRP on the pressure switch.
- Power Present + Code 2 = Bad 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 ⇒
- Check for a Clogged Pressure Port.
- Remove the inducer assembly and check the condition of the blower wheel.