1. Do not store items next to or on the furnace.
While your furnace is likely in an area that you use for storage, make sure there are not items directly next to the furnace or on top of the furnace. Crowding the furnace can decrease its efficiency. Additionally, items could potentially catch fire.
2. Keep flammable substances away from the furnace.
The furnace contains fire and some serious heat. Do not keep anything flammable near the unit, including paint, cleaning products, gasoline, oil or acetone, or other flammable materials. When these substances reach their flash point, they will ignite.