Inquire about how long your repairman has been in business. Inquire about their education while you're at it. While an HVAC specialist with one year of experience may be competent, it is far less likely than one with 15 or 20 years. Five Star Heating & Air INC can tell you that we've been servicing Palatine for than 40 years, that we have an excellent reputation as a Palatine heating company, and that we do excellent service. For additional information, go to https://fivestarheating.com/