A-1 Guaranteed Heating & Air, Inc., services homes and offices in Concord. It improves the functionality, energy usage, and life span of clients' heating and cooling systems through preventative maintenance solutions. Its technicians handle the installation of new equipment and the replacement of damaged and outdated pieces. The company, which has 26 years of experience, won the Best Heating and Air Award from The Daily Republic. The Times Herald newspaper also recognized it as the best in the Heating and Air category for 16 years.