Preventative maintenence inspection on four geothermal systems. All filters are in clean condition. Test ran operation of all units in electric heating and geothermal heating modes. Tested blower motors. During electric heating, tested operation of heating strips. During operation of geothermal heating, tested ground loop temperature and pressures. Did not check any refrigerant pressures as there are no issues suspected. All systems are operating properly, efficiently and ready for Winter.