When the brutal winds of January sweep across Lake Ontario and the temperature in Hamilton drops to a bone-chilling -18°C, your home should be your warm, cozy sanctuary. But what happens when you have the thermostat cranked up to 22°C, the furnace is roaring in the basement, yet you are still sitting on the couch wrapped in three blankets? Many homeowners immediately assume their furnace is broken. But what if it’s functioning exactly as it was installed to function—it’s just