Matter Dimmer Switch – Black, Push/Rotary, No Neutral, HomeKit, Alexa & SmartThings

The SM323 Matter dimmer uses the same proven hardware platform as our Zigbee SM323 — same dimming circuitry, wiring, and form factor — but communicates via Matter Over Thread instead of Zigbee. Matter offers native support across Apple Home, Google Home, Alexa and SmartThings without proprietary apps or vendor lock-in. You will need a Thread Border Router on your network.

It is natively compatible with Apple Home (HomeKit), Google Home / Nest, Amazon Alexa, and Samsung SmartThings via Matter — no proprietary app or vendor lock-in required. Home Assistant and Hubitat are also supported, though their Matter integration is still evolving and may expose basic on/off and dimming ahead of more advanced features.

Yes. Compatible Thread Border Routers include: HomePod mini, HomePod (2nd gen), Apple TV 4K (2021+), Nest Hub (2nd gen), Nest Hub Max, Nest WiFi Pro, Google TV 4K, Echo (4th gen), Echo Show 8/10 (3rd gen), Echo Show 15 (2nd), Echo Hub, eero WiFi routers, SmartThings Hub v3, SmartThings Station, and Aeotec Smart Home Hub.

No, the SM323 Matter dimmer does not require a neutral wire — it works in both no-neutral and conventional installations. In no-neutral wiring, bridge the L and N terminals as shown in the wiring diagram. If a neutral is present at the switch position, connect it normally for the most stable performance.

The SM323 Matter dimmer handles up to 175W of dimmable LED load and up to 350W of incandescent or halogen load, with 230VAC input. It is a trailing-edge dimmer suitable for modern LED lighting. Refer to the Bulbs Compatibility Matrix tab for compatible load sources.

Yes. Once commissioned, the SM323 dimmer operates locally over Matter Over Thread. Internet access may be required for initial setup and some controller features, but basic on/off and dimming continues to work locally — even if your WiFi or broadband is down.

Yes — lights connected to the SM323 Matter can be turned on or off either by rotating the knob or by simply pressing it. If you want to avoid dimming altogether, just use the press action. Note that with non-dimmable bulbs, accidentally rotating the knob can still cause slight flickering, so dimmable bulbs are always preferred where possible.

The SM323 Matter is designed to be wired directly to standard 220–240V dimmable bulbs and does not support a true decoupled or smart-bulb mode. As a workaround, you can wire the dimmer with Live and Neutral only (no light load attached) so it appears in your Matter controller (Apple Home, Google Home, Alexa, SmartThings, etc.). You can then use it as a trigger for automations that control other smart devices. In this setup only the on/off action is reliable — rotating the knob will not translate to dimming on remote devices.

Samotech faceplates are made of plastic except the Chrome and Brass finishes, which are metal. All knobs are made of high quality aluminium except where the variant name specifically states plastic (for example, "white plastic"). Check the variant you have selected on the product page for the exact material.

Ensure you follow the wiring diagram correctly. If your SM323 Matter dimmer is installed without a neutral wire, make sure to bridge the L and N terminals as indicated in the wiring diagram.

This can occur when the dimmer is connected to a very low load. Fitting a bypass capacitor at the light fitting is recommended in such cases.

To factory reset the dimmer, switch the power off and on five times from the consumer unit or circuit breaker. After the final power-on, the dimmer will enter pairing mode automatically.