If you have a fireplace, you will want to make sure you have it cleaned before using it unless you did so at the end of the season. Dangerous levels of creosote can build up on the inside of the flue and could become a fire hazard. Regardless of the type of fireplace or woodstove, if you burn combustible materials and have a flue, make sure to clean it before starting to use it again.

Make sure that the damper is tightly sealed when not in use to prevent heat loss. Even a small space can let the cold air in and let the warm air out. If you are using another energy system to heat your home and only using the fireplace occasionally, you will make your system work harder burning more energy if the heat is being lost up a flue that is not closed properly.

The furnace should be serviced annually if possible to keep it working at peak performance. Change the filters often since the furnace will work harder if the filter is full of dirt. A dirty filter causes energy waste since the furnace will consume more power to provide the same amount of service. The owner's manual will tell you how to clean the filter.

https://spontaneousreview.com/power-efficiency-guide-review/