Lennox Error Code E114 indicates Line voltage frequency out of range (not 60 Hz). 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
Line voltage frequency out of range (not 60 Hz)
Unknown
No 60 Hz power supply
Check voltage and line‑power frequency; correct frequency problems; system resumes normal operation 5 seconds after recovery
Power supply
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: