To install a programmable thermostat easily, a person needs a level, pencil, drill, tape and screwdriver. The electricity should be turned off and tested with a multimeter before removing the old thermostat.
When removing the old thermostat, the wall plate should be removed at the same time. If the thermostat is old, it may contain mercury. Caution should be used when handling it, and a person should check with a local recycling company to find out how to dispose of the thermostat. A person may want to label the wires on the system and note where they were attached to the old thermostat. These labels should not be based on color but labeled with letters or numbers. The wires need to be secured, so they do not fall into the wall.
The new wall plate can now be installed, and a level may need to be used if new holes or drywall anchors are needed. Each labeled wire should then be matched to the new terminal and connected based on the manufacturer's instructions. If batteries are needed, they should also be installed. The unit can then be mounted into the wall plate. At this point, the power to the home can be restored, and the thermostat can be tested. If it works, it can be programmed and used.