Lennox Error Code E272 indicates Soft lockout – exceeded maximum number of recycles; last recycle due to pressure switch opening. 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
Soft lockout – exceeded maximum number of recycles; last recycle due to pressure switch opening
Unknown
Pressure switch failure causing recycles
Check operation of low pressure switch to see if it is stuck closed on heat call; check pressure of high pressure switch closing on heat call; measure operating pressure; inspect vent and combustion air inducer for correct operation and restriction; clears when heat call finishes successfully
Low and high pressure switches, vent system, combustion air inducer
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: