Well one of my Heil heat pumps crapped out today. Heres the problem: Last week one day when I came home from work, I noticed downstairs was extremely hot, Air was blowing, but it was not cold. I killed the power, went out and took a look at it and saw nothing out of the ordinary. Turned the power back on and it started working fine, worked for a week. Came home today and same thing, coils about same temp as outside air, outside fan is running but no cold air in the house. Any idea as to what I can check before I call a AC guy?