Lennox Error Code E161 indicates Refrigerant leak detector sensor #2 type incorrect. Start by checking the most common and safe items identified in the troubleshooting section. If the code returns after those checks, professional diagnosis is recommended.
Easy
Refrigerant leak detector sensor #2 type incorrect
Unknown
Sensor #2 type not suitable for the application
Replace sensor with Lennox‑approved part; fault clears when correct sensor detected (blower latches for minimum 5 minutes)
Sensor #2
Call an HVAC technician if the error persists after completing the recommended basic troubleshooting steps or if the system repeatedly locks out.
Disconnect power before inspecting the equipment. Never bypass safety devices or operate the system if you suspect unsafe conditions.
Learn more about the furnace components and operating conditions commonly associated with diagnostic error codes: