Certifications at Jett's Heating & Air Inc. We’re dedicated to providing the Crystal Lake community with the best heating and cooling service around. To do so, we’ve gone through rigorous training to receive the industry certifications you see below. Learn more about our certifications here and give us a shout at 815-459-4700 to speak with a team member. Dave Lennox Premier Dealer™ To receive status as a Dave Lennox Premier Dealer™, Jett's Heating & Air Inc. in Crystal Lake was trained and is routinely independently evaluated to ensure we offer an unmatched level of customer service. We’ve partnered with Lennox®, a leading name in home comfort, to carry some of the best heating and cooling products in the industry. We sustain our Dave Lennox Premier Dealer™ status by participating in an independent Customer Review program. The program encourages customers provide honest feedback and ratings on the quality of our service and keeps us accountable for performing high quality work and customer service at all times.