How To Install a Programmable Thermostat (and Save Loads of Energy and Money).

by on Dec 11, 2007

A programmable thermostat cost only $40, and they’re terribly convenient. It’ll ease your lifestyle and your ecological footprint. Your home can be nice and toasty when you wake up, but cooler when your snuggly beneath the covers. Recently, I was asked to help install a programmable thermostat in a neighbor’s home, so here’s some photos and a brief how-to.

Need some motivation? Click here for ten great reasons to install a programmable model.

Steps to install programmable thermostat for your healthy home.


  • Programmable thermostat
  • Small flat head and Phillips screwdrivers
  • Electric drill and 3/16” bit (optional)
  • Pencil (optional)
  • Level (optional)

***Always follow the directions included on the packaging. These are intended as a supplement and inspiration.

1. THIS IS THE MOST IMPORTANT STEP: Turn off the electricity! At the circuit breaker, turn off every switch you can (even the refrigerator, it won’t take very long), especially the furnace, AC, and anything in the room where you’re working.
2. Remove the face plate of the old thermostat and perhaps a second piece (such as the thermometer) until you see the wiring coming from the walls.

It displays that how to install a programmable thermoast and save loads of energy and money.

3.Note the letters on the terminals where the wires attach. Use the stickers that came with your thermostat to mark the wires with the corresponding letters.

 A bunch of colorful wires with one of them having a note that says "Y1."

4. Now, unscrew the wires and remove the old thermostat entirely from the wall.
5. Separate your new thermostat into its component parts, mostly likely a wall plate and a face place.
6. Attach the wall plate to the wall using the included hardware. If the holes don’t line up, use the pencil to mark the spot for the new screws, and then drill a pilot hole.
7. Now, attach the wires to the corresponding terminals on your new thermostat.

Backside of a thermostat with wires attached to the corresponding connections.
8. Lastly, put the face on, and program as described in the instructions.
9. If you’re sure everything is connected correctly, turn the electricity back on. Turn the fan to on, and relish in your success!

*Contact the waste management company for disposal of your old thermostat (if it contains mercury).