Performed preventative maintenance on 2 Goodman Furnaces. Customer changes filters regularly and changed them recently. Cleaned flame sensor and brushed dust off the components. I inspected the blower assemblies, electrical components, heat exchangers, flame sensors, ignitor, burners, evaporator coils, heating drains, and overall condition and operation of equipment. Checked and tested thermostat operation, wiring, safety switches, pressure switches, amps, temperature rise and gas pressure. Downstairs inducer motor is making a whining noise on start up, but goes away after furnace ignites. The amps are within range 2.9/3.7 and continued to stay between 2.9 and 3.1 throughout the duration that the heater was one. Overall both systems are heating properly within manufactured specifications.