With more than 25 years of experience under our belts, it’s easy to see why Slinger and Hartford homeowners keep recommending us to their friends, family, and neighbors. We take pride in getting the job done right the first time, whether you need your furnace, air conditioner, or indoor air quality products fixed, installed, or maintained. Veteran-Owned and -Operated Since the Beginning After years in the Army, Jim McNall joined the heating and cooling industry, learning how to expertly repair and service furnaces and air conditioners of all kinds. He branched out on his own in 2009, using his expertise and hard work ethic to open JM Heating. Today, Jim and Austin help people stay comfortable in their homes, helping them problem-solve, troubleshoot, and repair any home comfort issues that arise.