Installing a Dimmer Switch
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Replacing a standard light switch with a dimmer is one of the simplest electrical projects. The wiring is identical: hot wire in, hot wire out, ground. The swap takes 15-20 minutes once the breaker is off. The important part is choosing a dimmer that matches your bulb type (LED dimmers for LED bulbs, specifically).
Cost Breakdown
Safety
Confirm the circuit is dead at the switch box before touching any wires. Do this every time, even if the breaker is off.
Swap
Flathead for the cover plate screws and wire terminal screws. Phillips for the switch mounting screws.
Strip wire ends if they are too short or damaged. Most dimmers need 3/4 inch of bare wire.
Helps bend wire into hooks for screw terminals and push wires back into the box.
Consumables and Supplies
These get used up during the project. Always buy these new.
- Dimmer switch LED/CFL compatible dimmer for LED bulbs. Check wattage rating covers your total fixture load.
- Wire nuts Usually included with the dimmer. Match size to wire gauge.
- Electrical tape Wrap wire nut connections for security
Safety Gear
- Non-contact voltage tester (listed above, but it is safety equipment)
Before You Buy Anything
Check if your neighbors already have the tools you need. Borrowing saves money, saves storage space, and keeps tools in use instead of collecting dust.
See how FriendsWithTools worksCommon Questions
Why do my LED bulbs flicker with my new dimmer?
The dimmer is not LED-compatible. Standard incandescent dimmers chop the AC waveform in a way that makes LEDs flicker or buzz. Buy a dimmer labeled "LED/CFL compatible" or "ELV" (electronic low voltage). Check the dimmer manufacturer website for a compatible bulb list. Not all LED bulbs work with all LED dimmers.
Can I install a dimmer on a 3-way switch?
Yes, but you need a 3-way dimmer specifically. A 3-way circuit has two switches controlling one light. Replace one of the switches with a 3-way dimmer. The other switch stays standard. The dimmer goes in the box with three traveler wires (plus ground). If you are not sure which box is which, label the wires before disconnecting.