Performed a full system inspection. Upon inspection found that the gas furnace is from 2014 and it’s a 3 ton. The AC system is from 2023 and is a 2.5 ton. upon arrival customer stated that he did not believe he had a filter in his system. Upon inspection found that the system did have a filter inside the furnace. This filter was not doing the unit any justice due to the blower just sucks it into the blower. During fall inspection found that the heat exchanger has lots of rust and could is failing. This is going to be due to airflow and age. This system only has one 12 inch return which is on my 480 CFM’s and what is needed for the system to work properly is 1000 CFM’s. This system has no UV protection. This system does not have TE standard flood protection. The outdoor unit is clean, and contactor and capacitor are both good. Due to condition of unit customer is wanting a quote to replace system furnace only, and compare prices whether he would want to repair this system and try to pr