A flame-rollout safety switch is open. Stop using the furnace and have it inspected before restarting.
Professional Required
Open roll‑out switch
Furnace fails to operate; LED displays E11
Open roll‑out switch caused by incorrect gas pressure, misaligned burners or burner restriction
Turn off the furnace and contact a qualified HVAC technician. Do not reset or bypass the rollout switch; a technician must determine why the safety device opened.
Roll‑out switch, burners, gas supply
Do not restart the furnace until a qualified HVAC technician has investigated the safety fault.
If you smell gas, leave the area immediately and contact your gas utility or emergency services from a safe location. Never bypass furnace safety switches. Internal furnace servicing should be performed by qualified personnel.
Learn more about the furnace components and operating conditions commonly associated with diagnostic error codes: