I had a downward forced air trane xl80 installed 6 years ago, now this winter the hi-limit switch has been going off. When I open an area under the air filter to allow more air to flow, the unit stays on. For some reason the air conditioning coils were mounted above the air filter and not under the unit and cannot be cleaned at all. I think that these air conditioning coils are probably very dirty, but since it was installed the coils cannot be cleaned. The company that installed the furnace comes out once a year to clean the unit, but has never cleaned the air conditioning coils, and as one has said, who are the monkies that installled this. When I call the company I am getting no response. What are my options, in the chicago area? Page 3 has actual pictures.