Demand call on a 16 year old train heat pump split system. Found an open leak in the outdoor unit basically the factory copper is all going bad. Got up in the attic checked evaporator coil it’s in really bad shape as well not to mention there’s a bunch of growth in the air handler. There is water damage in the air handler due to a possible leak in the interior pan. I have shut power off to the outdoor unit the system is running in fan only .