Save a lot of money! Learn how to remove your old thermostat and install a new programmable thermostat—with no rewiring required.
You can reduce your home’s heating and cooling costs by about 15 percent with a programmable thermostat. It automatically keeps the temperature at a comfortable level when you’re home, but switches to an energy-saving level when you’re away or asleep. Programmable thermostats are available from home centers and hardware stores. The higher-priced models provide more programming options.
1. Turn off power to the heating and cooling systems at the main panel. Remove the old thermostat. There will be anywhere from two to five wires hooked up to the old thermostat. Mark the wires with a tab (or tape) and the letter that represents the terminal and unscrew them. Remove and discard the old thermostat.
2. Clip a clothespin to the cable so it doesn’t slide down inside the wall cavity and mount the new wall plate. Level the new mounting plate in position and mark the mounting screw holes. Drill 3/16-in. holes, insert drywall anchors and screw the plate to the wall.
3. If the thermostat has back-up batteries, insert them before wiring the new thermostat. Screw the system wiring to the screw terminals on the new thermostat using the letter labels as reference (strip the wires back if necessary). These letters are standard; hook them up to the same terminals on the new thermostat. Snap the thermostat to the mounting plate.