Pellet stoves can run all day. In fact, due to their cost-efficiency and relatively clean burn, many people are choosing to have them as the primary source of heat in their homes. They are safe enough to run unattended and various new technological advances give you the peace of mind to leave them running while you are out of the house, even if you have animals at home. Once the hopper is filled with pellets, the stove will continue to burn using its self-feeding system. Also, many newer stoves are fully programmable and can even be started and stopped using your cell phone while you are out.