Hello, i'm having problem with furnace, per HVAC tech, i have cracked heat exchange and need new furnace.... problem now is home warranty is refusing to replace because this is pre existing condition, according to hvac tech and home warranty.

per home warranty and tech they are telling me that home inspector would have notice this burn mark (caused by crack heat exchange). i didnt hire home inspection when bought the house it was forclose and bank was not going to repair anything anyway...

can you look at the picture and tell me if this is burn mark or rust from condensation? and would home inspector would notice crack heat exchange?

any advice would be very appreciated.

Thanks