If you answered yes to one or all these questions, it’s time to call a professional at Northwest Mechanical, Inc. Yes, most states require HVAC technicians to be certified, and for good reason. Hiring an unlicensed HVAC technician could lead to poor quality work, costly future expenses, and potential code violations. While different HVAC contractors might offer higher or lower prices than competitors, the best time to replace your HVAC system is when customer demand is low. The beginning of summer and the beginning of winter bring the most demand for HVAC systems, so if you can, consider replacing your HVAC units in the early spring or fall.