I know very little about furnaces. The furnace started making humming noise and started blowing cold air. (It blew more cooler as time went by) I called hvac back out because they replaced the hiv thermostat 3 months ago and it cost $275 including labor. This time they said I have a bad blower and it will cost me $565 plus the $60 diag fee. I am wondering does this sound right. Should I have someone else look at the furnace. The furnace is only 8yrs old. I mentioned that to the co, they said the blower part is from 1993Any advice? Is there something else I can do because I don't have that much $ right now.