26 yr old Lennox furnace. Unit ran when we turned it on. Checked gas pressure and found it to be high at 4.3 inwg, reduced it down to 3.2 inwg. Made sure drain was clear and the draft motor was pulling enough to close pressure switch. Furnace is rusty and showing its age. Customer has requested an appointment for pricing on new equipment. I will have office call to schedule an estimate on Monday.