Furnaces Clean or change furnace filters frequently, dirty filters block the airflow. Also, keep the outdoor coil free of debris. If possible, install a humidifier. Set the thermostat a few degrees lower during the night. Heat pump owners should set a desired temperature and leave it unless they have a special nighttime setback thermostat specifically designed for heat pumps.
Many people prefer a constant reduced temperature.
When away from home for several days, lower the thermostat. Thermostats for heating and air-conditioning should be on an inside wall or where they will not be subject to draft or heat from appliances. Clean the thermostat yearly by removing the cover and carefully blowing away any dust. Dust on radiators or baseboard units acts as insulation and wastes heat. Dust or vacuum these surfaces frequently.