Installing a three-way dimmer switch on an existing three-way switch circuit is not only a simple job, but it will add flexibility to your lighting design and improve the overall atmosphere of your living space. The primary thing that confuses most do-it-yourselfers is the fact that only one of the three-way switches needs to be replaced with the dimmer switch. If you replace both current three-way switches with two three-way dimmers, the circuit won’t function properly.
Your first step is to think about which of the two switches you use the most. This is the one that you should replace with the dimmer.
Follow these steps to replace an existing three-way switch with a three-way dimmer switch.
Step 1 - Turn Off Power
Turn off the power to the circuit.
Step 2 - Take Off the Cover
Remove the cover plate from the switch.
Step 3 - Unscrew
Remove the two screws that secure the switch to the wall box and gently pull the switch out. Double-check with a voltage tester that the power is off.
Step 4 - Remove Wires
Remove the wires from the existing three-way switch. It is imperative that you note or label which wire is on the dark/black colored screw. This is the common wire.
Step 5 - Connect Wires
The common wire must be connected to the dark screw or common wire on the new dimmer switch. The other two wires are travelers and can go on either screw terminal or wire lead.
Step 6 - Connect the Ground Screw
Connect the ground wire to the ground screw on the dimmer switch.
Step 7- Add Cover Plate
Install the new cover plate and turn the circuit back on.
That’s all it takes to replace an existing three-way light switch with a more innovative three-way dimmer switch