Lennox Error Code E151 indicates Refrigerant leak detector sensor #1 fault. 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 #1 fault
Unknown
Refrigerant detection sensor #1 reporting issue that prevents proper operation
Check sensor and wiring; replace sensor if necessary; fault clears when sensor reports no fault
Refrigerant detector sensor #1
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: