1st floor system. Performed preventative heat maintenance for a high efficiency Lennox furnace. Model #EL296UH079XE36B-03, serial #5919K07063. Upon arrival the system was set for heat. I raised the temperature by 10° and observed the system start Normally. I took a combustion analysis test and received the following readings o2 is at 9.7% and the co levels are 11ppm. The inducer motor amp draw is at .65 and the blower motor amp draw is at 3.2. I cycled the system down and allowed the manifold to cool. I removed the access panels and burner box plate. I removed and cleaned carbon off of the flame sensor. I cleaned out the burners and burner box. Checked all electrical connections to ensure that they are secure and in good condition. I tested the drain line and cleaned out the trap. The air filter size 16x25x1 was recently replaced by the homeowner. The blower motor and blower wheel are both clean and in good condition. I re attached the panels and called for heat to ensure proper operat