Came out to perform preventative maintenance on furnaces. Discussed with customer about service needed and how the new mini split was doing for them. Customer stated that the new mini split is working well and has no complaints. Cleaned mini split filter out and checked operation. Changed out air cleaner filters in home and found customer out of 14x24x1 filters. We ordered them and had them shipped to their home. Customer remembered getting them, but wasn’t sure what happened to them. We will order more and I will bring them and replace the two filters up stairs. Inspected blower assemblies, motors, electrical components, heat exchangers, burners, flame sensors, ignitors, gas valves, inducer motors and overall condition of equipment. Cleaned flame sensors and brushed dust off all of the components. Checked thermostat operation, wiring, amps, temperatures and gas pressures of all systems. All 3 systems are heating properly at this time. The downstairs unit and unit up in the attic are o