Lennox Error Code 417

Priority condition: Service Soon / Service Urgent System Detection and Operation: Priority condition: Service Soon / Service Urgent The outdoor unit discharge line temperature sensor is either open, short-circuited or the temperature is out of sensor range. • This fault is detected by allowing the unit to run for 90 seconds before checking discharge line sensor resistance. • If the discharge sensor resistance is not within range after 90 second period, the control will display the priority condition as service soon. • If the moderate condition continues for 10 minutes, the system changes the priority condition to service urgent. Priority condition: Service Soon / Service Urgent Possible Causes: Priority condition: Service Soon / Service Urgent • The applicable system component detects either an open, shorted or temperature out of range condition. • Discharge sensor leads located in wrong pin positions in harness plug-in connector. Refer to the applicable unit installation and service procedure and locate the terminal descriptions table to verify cable harness assembly wiring pin positions are correct. Priority condition: Service Soon / Service Urgent Possible Solutions: Priority condition: Service Soon / Service Urgent • Check the resistance of the discharge sensor and compare to temperature resistance chart located in the applicable unit installation and service procedure. If sensor resistance is out of range then replace the discharge line temperature sensor. • If discharge sensor wring leads are located in the wrong connector pin-out then order a replacement cable assembly.