Most furnaces either have all of their burners lit or all turned off. However, over 80% of the time, it is not necessary to have all of the burners of the furnace lit to meet the heat demands. Having all of the burners lit when it is not necessary causes wasted energy and an uncomfortable living environment. Choosing a new furnace is not an easy task, and it is a choice that you will live with for the next 15+ years. Consider each of the major options carefully to choose a furnace that is going to meet the needs of your family now and in the future.