Do It Yourself Installing a Programmable Thermostat

Imagine the air conditioning automatically cooling your home 10 minutes before you walk through the door. And wouldn’t it be nice not having to remember to bump the temperature back up as you leave for work? These small advantages make the programmable thermostat not only a budget-friendly upgrade, but a welcomed convenience.

Also on the market are smart programmable thermostats which are connected to Wi-Fi, allowing you to program your thermostat from your computer, tablet and smartphone.

According to the Department of Energy, installing a programmable thermostat can help you save between 5 and 15 percent on your monthly cooling and heating bills. The process to install a traditional programmable thermostat takes less than an hour, and with many models available starting at $25, you can recoup the initial expenditure after only one year of use.


  • Programmable Thermostat
  • Batteries (if applicable)
  • Screwdriver
  • Drill/driver
  1. Turn off the power supply to the thermostat at the breaker box and cut power to the indoor HVAC unit. This could be a switch or a breaker; it will be near the indoor air handler.
  2. Remove the old thermostat cover.
  3. Remove wires one at a time from the old thermostat and label each one with labels from the new thermostat. Once all the wires are labelled, remove the old thermostat plate from the wall. If the old thermostat contains mercury tubes, it must be recycled—check with your local hardware store for proper disposal.
  4. Install the new wall plate. Use a level and mark the location for the mounting holes. Drill the holes and, if needed, insert drywall anchors which should be provided with the new thermostat (this step will vary depending on the model). Feed the wires through the wall plate, pulling the wires out about an inch so they don’t fall back into the wall, then fasten the plate to the wall with a screwdriver.
  5. Follow the instructions in your manual to verify all the wires are connected correctly. The instructions should include two sets of wiring guides: one for a heat pump and one for a conventional (electric furnace) system.
  6. Install batteries (if appropriate) in the new thermostat and insert new faceplate.
  7. Restore power at the main breaker and next to the indoor air handler. Program the new thermostat according to the manufacturer’s instructions. Test the new thermostat to make sure it’s operating properly. If you have a heat pump, ensure the heat strips (auxiliary heat) are not coming on too soon or automatically—an indication of improper installation or an incompatible thermostat.

Installing a programmable thermostat is a small job that can have a big impact on your monthly cooling and heating bills. For proper installation and safety, be sure to follow the instructions precisely.