At the very least, your technician will simply tell you the furnace is good to go for the winter. If a replacement is actually necessary, it won’t be good news, but John’s Service and Sales can handle it. In general, though, a checkup will extend the life of your system. Professional HVAC technicians will make sure your system does its job throughout the winter months. Have them calibrate your thermostat, inspect your system as a whole, and tighten any electrical connections. And don’t forget, if you have a newer system it might be necessary to maintain it to keep your warranty valid.