Markool Heating & Cooling is a top furnace company serving Jefferson, MD with a full range of home comfort system services. We’re more than the average heating company! As a Carrier Factory Authorized Dealer, we offer a broad range of products and have skilled HVAC technicians. We install new heating systems or diagnose and repair your existing one with upfront pricing and clear communication. From taking the Maryland winter chill off to fighting a cold snap, we can help keep you warm.