Arrived to remedy an inoperable system. Upon inspection of the system, found it heating the home. Homeowner mentioned that the system was displaying a fault code 10 and fault code 11. Checked the manual for the furnace to verify the cause of these fault codes. Fault codes are related to ignition and ignition proving system. Cycled power on the furnace and tested the ignition system. Found that the burners would not all consistently light. Also found that when the burners light the flame sensor is not sensing that there is flame present spoke with homeowner about the system and with homeowner‘s approval, reached out to have new burners, brought out and set up to replace the flame sensor and spark igniter. Once burner assembly arrived, replaced the burners and installed the new igniter and flame sensor. Tested system operations. System is functioning properly at this time.