Thermostats are fairly easy to replace but be careful to do it carefully. Here are some steps that should be taken when replacing your old thermostat.

1. Turn off the power. This can’t be stressed enough. Turn off the power to the furnace and/or air conditioner as well as the main power to that circuit at the breaker box. Just out of abundance of caution, tape a note on the breaker box that says that you’re working with the electricity just to be sure that nobody accidentally turns on the power while you’re working. You don’t want any surprises while while you’re installing thermostats that are connected to the power supply.
2. Remove the faceplate. This should be fairly cut and dry.  Carefully remove the faceplate from the baseplate.
3. Remove the baseplate from the wall.  While removing the baseplate from the wall, do it carefully so as not to un-attach any wires that are connected to it.
4. Label all the wires. Take the time to label all of the wires. Label the wires with any information needed such as the corresponding letters that they are connected to. Re-installing thermostats is easy if you know where all the wires go.
5. Wrap the wires around a pencil, pen, or stick. Wrapping the wires around some object will keep them from disappearing back into the wall.
6. Re-attach the wires to the new thermostat base plate. Re-attach the wires using your tape labels and the new thermostat’s instructions as a guide.
7. Per the manufacturer’s instructions, attach the new baseplate to the wall. After the baseplate is attached, attach the faceplate to the baseplate.
8. Turn the power back on. That’s it. You’re done. Time to turn the power on and don’t forget to remove that note that you left on the breaker box.

Replacing thermostats is pretty easy. Just take the little extra time to label wires or wrap the wires around something so they don’t end up falling back into the wall and you’ll be fine. If you need more assistants contact your local plumber!