Customer has 13 y/o Goodman air handler matched with unknown age AC that operates for upper level. Primary and only source of heat are electric heat strips due to outdoor unit being an AC. Wired Ecobee for system setup. Tested heating and cooling. System is up currently working as electric heat and AC cooling. Informed customer that 5 strand wire from thermostat to air handler is not sufficient for heat pump application and only 2 wires from outdoor unit to air handler. New thermostat wire for complete system would have to be ran for heat pump application along with outdoor unit replacement. Due to age and condition of system, full system replacement is recommended. Noticed during inspection, no form of water protection present. Biological growth presence within air handler. Secondary pan is rusted. Blower wheel cleaning needed. Improper drain line installation. Inconsistent ductwork. Bad run capacitor. Informed customer of all findings.