This question was e-mailed by a reader.

I think a maintenance agreement or energy savings agreement is a great idea. Obviously it would only be worthwhile if it include a quality air conditioning tune up. A few considerations in choosing your HVAC contractor.
1. Are they providing a proper tune up?
2. Are they a full service company?
3. Do they have a seperate service department? You don't want to wait all summer for an understaffed company.
4. Do they offer a 15% discount if you should need service outside of the maintenance agreement.
5. Are their techs uniformed in lettered trucks?
6. Are they considerate in explaining what they found?
7. Is your home left clean free of footprints?
8. Are you offered priority service for breakdowns?