Be sure to get every quote or estimate in written form. You have no recourse on a verbal agreement, so a written contract is a must. This will allow you to follow up if something goes wrong or you don't get what you were promised, protecting you from shady contractors.
http://www.youtube.com/watch?v=J8jNyPsmIQM
Any contractor that gives you a quote over the phone shouldn't be trusted. To truly evaluate your needs, they must come into your home and check it out basement to attic. If they make promises without even seeing your house, there is no way they'll be able to keep them.
As you can see from the above article, with great tips and ideas it is much easier to take good care of your HVAC system. Now that you understand what keeps an HVAC running smoothly, yours should last a very long time. Refer back to these tips to whenever you spot a problem.
