Did a preventative maintenance on a gas furnace. During the maintenance I clean the flame sensor and I also cleaned out the trap for the high-efficiency furnace. And I made sure that the drain was draining. Also I did a combustion test the PPM was 28 and the O2 was nine. I did an amp check on the inducer motor and the blower motor which both me the furnace specs. Cleaned out the burner box and the blower motor housing customer changed filters. Filter size 3(14x14x1) 2(20x20x1) m#59SC2D080E17–16 s#2620A59266 customer paid for a 1 year maintenance agreement for a Air-conditioning tuneup in 2023 and customer used the heater maintenance today for her maintenance agreement System is operating properly at this time