A programmable thermostat may be a big energy saver if the building’s occupants understand how to program it. However, a programmable thermostat won’t save any energy if occupants already control day and night temperatures effectively.
If you replace the existing thermostat, as a part of weatherization work, discuss programmable thermostats with occupants. If they can use a programmable thermostat effectively, then install one. Educate occupants on the use of the thermostat and leave a copy of manufacturer’s directions with them.
Many models of programmable thermostats have settings that you select from inside the thermostat. These settings include the heat-anticipator setting, which adjusts the cycle length of the heating or cooling system.