For fast, reliable AC and heating service and repair in Harford County, Old Line Heating and Air is the team locals trust. Whether your furnace isn’t heating or your AC won’t cool, our technicians arrive quickly with the tools and experience to fix it right. We service all major brands and provide same-day appointments when possible. Our goal is to restore comfort fast—with fair prices and no upsells. We’ll explain what’s wrong and give you the honest options you need to make the best choice. Get expert service that lasts long after the repair is done.