Purchase a digital thermostat from a home improvement or hardware store. Turn off the power to your furnace before beginning digital thermostat installation.[1] X Research source Remove the cover of the old thermostat.[2] X Research source Most of them simply pop off easily with a little force. Remove the screws from the screw terminals in the sub-base of the old thermostat and remove it from the wall.[3] X Research source Disconnect the wires and label them with masking tape so you know where to connect them to the new digital thermostat.[4] X Research source There should be letters on the old unit next to each wire. Simply mark each spot with the tape with the corresponding letter on it. If the screw holes line up, you can use the old ones. If not, use a drill for new holes and use dry wall mounts if needed. Mount the sub-base of your new digital thermostat over the old location.[5] X Research source Attach the wires to the correct terminals in the new digital thermostat sub-base on the wall.[6] X Research source Put batteries in your new digital thermostat. Attach the cover of the new digital thermostat to the sub-base on the wall. Turn on the power to your furnace. Set the

temperature to your new digital thermostat and experience how efficiently it regulates the temperature in your home. If your digital thermostat is the programmable kind, simply program in the desired temperature. It will regulate the temperature in your home to this degree, and keep it there.