Lennox Error Code E290 indicates Ignitor circuit fault – failed ignitor or triggering circuitry. 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
Ignitor circuit fault – failed ignitor or triggering circuitry
Unknown
Ignitor circuit fault due to failed ignitor or triggering circuitry
Measure resistance of hot surface ignitor; replace if open or not within specifications; 1‑hour soft lockout; clears when flame has been proven stable
Hot surface ignitor
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: