Hi, I am new to this site, but my problem is that I came back from vacation and the air conditioner was not working. I have central air and it is a Bryant Air conditioner. It is about 18 years old. I went out to look at the air conditioner, the line from the air conditioner had a ball of ice covering it, and the line into the house, where the black rubber coating was missing, was covered in ice. I tried turing on the fan, and putting it on, on all the time, nothing was happening. I could hear fluid or something running through the ac line by the furnace, but nothing happing at the furnace. I have a high efficiency furnace, train xl90... does it sound like the ac is fine, but there is problems at the furnace? Why is the line freezing up... any help would be greatly appreciated.. thank you.