Arrived onsite for heating maintenance 1 gas fired furnace located in basement. Ask customer to turn heat on and confirmed operation. Changed filter 16x25x1. Brushed and Wiped down blower cabinet and gas burners. Burners fired and are in good working order. Observed visual impingement detected. Checked electrical. Measured .5 amps on the hot surface igniter. Cleaned and Measured 4.9 micro amps on the flame sensor. Measured 135 degrees at the air supply and 80 degrees at the return for 55 degree heat rise within specifications. Furnace is operating as it should but showing its age.
