Energy and money savings can be substantial in the winter by turning down your thermostat. In the upper Midwest, for example, setting back the temperature from 68 to 55 at night can save at least $10 to $20 a month on fuel. You will achieve such savings with any thermostat--if you remember to set and reset it daily; or you can use an automatic setback thermostat. A setback thermostat offers comfort and convenience since it can turn the heat on before you get out of bed or raise the temperature before you come home in the evening. A setback thermostat also offers dependability since it will automatically change the temperature day in and day out. There are two types of setback thermostat. Digital electronic models offer the greatest number of temperature settings and setback periods, but are complex. Electromechanical thermostats are easier to set but have fewer features and less flexibility.
These descriptions and recommendations do NOT apply to heat pumps unless a special heat pump thermostat is used. Refer to the section on Heat Pumps.
Thermostat makers routinely offer dozens of variations on a given model, to make the thermostat compatible with different central heating systems, central air-conditioners, or both. They are designed for do-it-yourself installation.