Programmable thermostats offer new methods of conserving energy and increasing comfort. Installation can be done by the homeowner, but there are different thermostats for each type of system. Zoned systems with the selector switch (heat-off cool) at the thermostat require a thermostat with changeover terminals. Heat pumps need a two stage thermostat. Fuel burning thermostats might need a thermostat with extra terminals if equipped with air conditioning.
A programmable thermostat combines convenience with conservation. It may be programmed to conserve energy by lowering the demand for heat during inactive hours. Users may program the heat to remain at a lower temperature at night while they sleep and restore it to room temperature just before they get out of bed. Likewise, the thermostat can turn the heat down right after a person leaves for work and have it back up to room temperature when they return from work.