I’ve had the same furnace for about fifteen years, and I’m wanting to replace it. My old furnace still works, but it lacks modern features. The current heating system can be described as a two-stage model, which means the furnace cannot adjust its speed. That furnace either runs at highest capacity or it shuts all the way down completely. This causes the system to blast heat steadily until it achieves the thermostat setting. It then turns off until the temperature drops, before starting the process yet again. The result is uncomfortable heat fluctuations and constant cycling on and off. Because the furnace is so terribly outdated, it is not suitable for zone control or a smart thermostat. Plus, even at peak energy efficiency, the furnace comes with a 89 percent AFUE rating. Newer models manage to hit 98 percent AFUE ratings. I could most definitely save a tremendous amount on my monthly heating costs. And I’m sure that my old furnace is no longer operating at maximum strength. Despite having it expertly serviced every fall, it is impossible to maintain all components in pristine state. I’m suspicious that there is a lot of dust and contaminants concealed inside the inner workings. Whenever the furnace begins, I notice dust flying around in the air. I have done a bit of research, and I would always purchase a modern furnace showcasing variable-speed operation. The heating equipment would manage to adjust speed anywhere between forty and a hundred percent capacity. Along with more even temperature at home, this would trim costs.