One of the worst things that anyone can do is let their heating system go without regular maintenance. Every cold season will put a huge strain on a heater and the overall duct system, which can lead to serious mechanical problems over time. Most importantly, owners are going to be losing quite a bit of their efficiency through cracks, leaks, and older filters.
Lastly, an efficient system is going to consistently keep a home at a comfortable temperature, making the building more pleasant to live in as the cold weather sets in. You will not have to worry about being without heat during the times you need it the most.