- Shut off power to your old device. Go to the circuit breaker in the house and flip it off for this area.
- Remove the old thermostat from the wall. Unscrew each corner and take it down. Notice the placement of the electrical wires if its a similar model.
- Hook the wires into the back of the Marley MD26. Connect each wire to the proper terminal and tighten them down. R goes to Red, G goes to Green, Y goes to Yellow and W goes to White.
- Fasten the thermostat to the wall by drilling the screws in. Each corner should hold the device flat against the wall.
- Turn the power back on through the circuit breaker. Program the Marley once it powers on.
Things You Will Need
- Use the remaining screw holes if they will fit your new device.
- According to "Black & Decker's The Complete Guide to Wiring: 5th Edition," by the editors of CPi, "Most DIYers who have done it will agree that home wiring is fun and rewarding. But it is also fraught with danger" (See Reference 1).