I was referred to this awesome site.  It has a ton of information on home furnace problems, also tips on how you can possible fix the issues yourself.	
	
This site helped me to solve the problem I was having which was too much heat coming out.  It turns out the thermostat was crooked on the wall, and when I made it straight, the issue was solved!  I'm not at all handy but even I could handle this one.  Great advice and help from this boulder website.  Check it out for furnace questions, problems and help!
                        
more