Completed annual maintenance on one gas furnace, changed return filter 14x25x1 that customer provided, cleaned flame sensor, inspected igniter, cleared p trap, inspected heat exchanger, checked pressure switch, tested capacitor which tested in range, blower wheel and ducts clean home is only two years old, all amp readings normal, temperature rise was 50 degrees, performed combustion and efficiency test which system looked normal, tested both zones, put thermostat back to where they were set, customer signed up for maintenance agreement and system operational. Mail invoice to customer.