Customer has 6 y/o 2-zone Rheem heat pump system that operates for whole house. System is not cooling due to low pressure levels indicating loss of refrigerant. Performed electronic leak search and found that system has bad evaporator coil. Evaporator coil is also rusted. Noticed during inspection, that biological growth is present. Blower wheel is also dirty. Condenser coils are dirty as well. Replaced 20x20x1 filter. Informed customer of findings. Advised customer to seek options for system upgrade, particularly due to system no longer being under warranty, which expired 2/2023. Customer would like to review options. Outdoor unit disconnect left in OFF position to avoid any further damage.