How to Install a Kasa HS220 3-Way Dimmer Kit

Overview

Install the Kasa HS220 3-way dimmer and companion switch in a standard 3-way circuit with neutral wiring, pair with the Kasa app, and validate dimming behavior from both switch locations for smart control.

What's Included

• Two existing 3-way switch locations
• Neutral wire present in primary box
• Ground wire connected at both boxes
• Kasa app installed on phone
• Household WiFi has 2.4GHz SSID
• Breaker confirmed off with tester

Got your materials ready? Here's what to check first.

Before You Start

• Line and load misidentified at primary
• Traveler wires not mapped correctly
• Neutral absent in main switch box
• Companion installed in wrong location
• Bulb type incompatible with dimmer
• Primary paired to wrong network

Tools & Requirements

Installation Steps

1

Kill Power and Map

Turn off the breaker and confirm power is off using a non-contact voltage tester. Open both switch boxes and photograph existing wiring before disconnecting. Write down which conductor is line, load, ground, and travelers. A clear map prevents costly mistakes during install.

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2

Install HS220 Primary

Choose the box with line conductor and neutral bundle as the primary. Land line on L, load on Load, travelers on Traveler, neutral on N, and ground on green. Tighten terminals firmly. The primary is the only location that needs neutral for smart features.

3

Install Companion

At the secondary box, install the Kasa companion switch. Connect travelers and ground per the instruction diagram. The companion does not require neutral and does not appear as a separate smart device because it communicates with the primary via travelers.

4

Power Up and Pair

Restore breaker power. Open Kasa, tap Add Device, and choose Smart Dimmer. Complete onboarding and select your 2.4GHz WiFi. Confirm the primary switch responds to app dim commands before moving the phone near the secondary switch for manual testing.

5

Test From Both

Toggle the primary HS220 and the companion to verify dimming from both ends. Test presets and schedules. If behavior looks reversed, swap traveler wires per the wiring guide. Confirm LEDs do not flicker at low dim levels, then label both boxes.

Installation Tips

Still stuck? This is usually the deeper cause below.

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