Lennox Equipment not specified Error Code 35

Priority condition: Service Urgent • Message sent by thermostat to unit after more than 15 minutes asking for initiating heating or cooling with no response from unit. • Message sent by thermostat to unit after more than 15 minutes asking for termination of heating or cooling with no response from unit. Priority condition: Service Urgent Result Priority condition: Service Urgent A communicating device in the system has been disabled due to a fault/lockout code in the unit’s control. Another possible cause is electrical noise interference affecting the communicating system when the compressor contactor coil is energized. Priority condition: Service Urgent Corrective Action: Priority condition: Service Urgent • Communicating system: Wire a transient voltage suppressor in parallel with the compressor contactor coil terminals on the outdoor unit. • Non-communicating outdoor unit: Wire transient voltage suppressor (89W72) in parallel with compressor contactor coil or across the Y1 and C terminals on the indoor control board. NOTE: See service and application note IAQ-10-01 for further details. Transient Voltage Suppressor Part information: Made by Little Fuse, part number 5KP43CA bidirectional Transorb aka TVS Diode. Please contact your FTC or inside technical support for help in acquiring the transient voltage suppressor if not available in your local electronics store.