There are many steps that can be taken to improve furnace efficiency, most of which are very simple and can be done in just a few minutes. However, faithfully following these steps could save a substantial amount of money over the course of a heating season. There are very few cases where a furnace operates at its maximum efficiency, so improvements can always be made.
One of the easiest ways to make your furnace more efficient is to make sure that the air filters are replaced every three months. This allows air to pass through the furnace more efficiently. If air is blocked because of a clogged filter, the furnace has to work harder to adequately heat the home. Air filters can fill with dust and debris fairly quickly with regular use, making quarterly replacement even more important. Filters come in a variety of price ranges, depending on the quality. Most range from $1 US Dollar (USD) per filter to $15 or $20 USD.
Another factor in working to improve furnace efficiency is to make sure the furnace is inspected before the start of each heating season. While this may cost $100 USD or more, it can save money in the long run. There are things a professional can tell you about your furnace that you may not know. Further, the professional can make sure your furnace is running at the proper fuel to air ratio, another key required to get better furnace efficiency. Also, the professional inspector may be able to provide you with some tips to maintain better heating efficiency.
Another way to improve furnace efficiency, or at least improve the efficiency of the overall heating system, is to inspect the ducts. These are the conduits that carry the hot air (in the winter) or the cold air (in the warmer months) to the rest of the house. Any large holes will dramatically reduce the efficiency of the furnace, simply because heated air is being wasted. To make up for that wasted heat, more heating is necessary. For homes with a basement, at least inspecting the exposed portions of ducts is recommended.
For those who are still not satisfied, a nearly guaranteed way to improve furnace efficiency is to buy a new furnace. Gas furnaces are usually most efficient. While this may be a more expensive way to improve furnace efficiency, improvements in technology and insulation will help provide you with a much more energy efficient furnace, especially if your current furnace is ten or more years old.