Technician arrived on site to perform maintenance on 5 ton split system. Today’s visit is on furnace. Checked the following: -hot surface igniter ohms -flame sensor -temp split -inducer amps -blower amps -blower wheel -filter condition -gas piping -vent piping -safety switches Overall unit is in good health. Filter was bad but changed it out with a customer supplied one. Adjusted fan settings to circulate instead of “onâ€