came out to perform a home inspections. The indoor unit is a 1993 gas furnace the outdoor is 2010 410a. After fully diagnosing the system the indoor has a cracked heat exchanger and we verified the cracks with the inspection camera as well as recorded the flame rollout, discoloration, and flames bouncing. we also inspected the evaporator coil and it was completely rusted out and full of pet hair. the blower motor was amping very high and also completely covered in pet hair. we checked the duct work some of the duct. work was compromised. The system did not have a return plenum the ducts were cut directly into the system. there was more duct work than the system could provide for, a duct was added by the customer for a sun room causing high static pressure and low airflow. the drain line was not pitched nor did it have a safety device to prevent flooding and did not have a clean out. Upon inspecting the outdoor system we found that it was very dirty and heavily impacted by pine straw