Thermostats control the heating and cooling temperatures in the home. Many people are replacing their manual thermostats with programmable thermostats. Different manufacturers install their thermostats in varying ways. Honeywell thermostats use a mounting plate to slide the thermostat body into. You only need one hand tool to remove the thermostat. Take some time to keep the thermostat wires identified and you will have a smoother installation process afterward.
Turn the power supply off to the furnace. You can turn the power off either by the red emergency near the furnace or at the circuit breaker in the home electrical panel.
Slide the Honeywell thermostat body up to release the body from the mounting plate on the wall. Pull the thermostat away from the wall enough that you can access the wires behind the thermostat.
Wrap small pieces of masking tape around each individual wire. The wire terminals on the back of the thermostat have identification letters. Write the letter to the corresponding wire on the masking tape with a pencil.
Loosen the terminal screws on the back of the thermostat with a Phillips-head screwdriver. Pull the wires off of the thermostat terminal and wrap the wires around the pencil. The pencil will keep the wires from falling into the wall cavity while they are loose.
Remove the screws securing the mounting plate to the wall with a Phillips-head screwdriver. Carefully thread the pencil and wires through the centre of the mounting plate while pulling the mounting plate away from the wall.
Tape the wires to the side of the wall with masking tape until you are ready to install the new thermostat.