1-Gang White dimmer with plastic white knobs - alternative view
2-Gang White dimmer with plastic white knobs - alternative view
3-Gang White dimmer with plastic white knobs - alternative view
4-Gang White dimmer with plastic white knobs - alternative view

Matter Dimmer Switch – Push/Rotary, No Neutral, HomeKit, Alexa & SmartThings (SM323-MT)

(13 customer reviews)

£38.99 – £107.99

Matter dimmer switch – UK’s first Matter Over Thread Rotary Dimmer from SAMOTECH. Local control with Apple Home, Google, Alexa & SmartThings. No neutral required.

 

  • Matter over Thread – native multi-admin control across Apple Home, Google Home, Alexa and SmartThings simultaneously
  • No neutral required – works on UK two-wire lighting circuits (neutral connection optional if available)
  • Local control on a self-healing Thread mesh – no cloud round-trip, responds even if the internet drops
  • Dims up to 150 W LED and 350 W incandescent or halogen
  • Thread Border Router required (Apple TV 4K, HomePod mini, Eero, recent Nest Hub or any Matter-compatible hub)
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Description

We’re excited to release the first Matter Over Thread dimmer in the UK, using the same reliable foundation as our trusted Zigbee SM323 module. Building on our original Zigbee rotary dimmer launch five years ago, this new version brings Matter-over-Thread compatibility to UK homes.

Designed for integration across Apple Home, Google Home, Amazon Alexa, and Samsung SmartThings, the new SAMOTECH Matter Over Thread Trailing Edge Dimmer offers an ideal in compatibility, responsiveness, and energy-efficient performance.

⚙️ Key Features:

  • Matter over Thread Technology
    Enjoy ultra-fast, low-latency control with a self-healing mesh network. Thread ensures your dimmer stays responsive – even if your WIFI is down – and contributes to a more stable, scalable smart home.

  • Smooth & Silent Dimming
    The advanced trailing edge control allows precise dimming from 0–100% with no buzzing – ideal for modern LED lighting.

  • Works with All Major Platforms
    Native support for Apple HomeKit, Google Assistant, Amazon Alexa, and Samsung SmartThings via Matter – no need for proprietary apps or vendor lock-in.

  • Neutral Optional Installation
    Compatible with both neutral and no‑neutral wiring configurations, making it ideal for UK homes. The Matter dimmer also supports 2‑way wiring when used with retractive light switches.

  • Energy Efficient & Future-Proof
    Thread is designed for low power usage, making it ideal for energy-conscious homes. With Matter’s unified standard, your setup is ready for future smart home devices and updates.

  • Secure, Local Control
    All commands are executed locally via Thread, not through the cloud – meaning faster performance, improved reliability, and enhanced privacy.

🔧 Ideal For:

  • LED downlights and dimmable ceiling fixtures

  • Retrofitting existing wall switches

  • Users looking for reliable automation without WIFI dependency

Whether you’re building your smart home from scratch or upgrading an existing setup, our Matter over Thread Dimmer is the intelligent choice for future-ready lighting control – the performance you trust, now with the new standard.

Ecosystem Compatible with Matter-over-Thread? Supported Border Routers / Hubs
Apple (HomeKit) Yes HomePod Mini, HomePod (2nd gen), Apple TV 4K (2021+)
Google (Nest / Home) Yes Nest Hub (2nd gen), Nest Hub Max, Google TV 4K, Nest Wifi Pro
Amazon (Alexa / Eero) Yes Echo (4th gen), Echo Show 8 & 10 (3rd gen), Echo Show 15 (2nd), Echo Hub, eero Wi-Fi routers
Samsung (SmartThings) Yes SmartThings Hub v3, SmartThings Station, Aeotec Smart Home Hub

Known limitations

Home Assistant (Matter)
• Matter support is still evolving and depends on your Home Assistant version.
• Basic on/off and dimming are supported; advanced features may appear later.
• Acting as both Matter controller and Matter bridge requires additional configuration and supported hardware.
Apple Home (Matter over Thread)
• Requires at least one Thread Border Router (HomePod mini, HomePod 2nd gen, or Apple TV 4K with Thread).
• Sharing to other Matter controllers must be done manually via Apple Home’s sharing flow.
• Advanced automations are limited to what Apple Home exposes via Matter (no device-specific extras).
Google Home (Matter over Thread)
• Requires a Thread-capable Google device (e.g. Nest Hub 2nd gen, Nest WiFi Pro).
• Commissioning can fail if multiple Google Homes or accounts are present – ensure the correct Home is selected.
• Automation options are improving but still more limited than native Google devices.
Hubitat (Matter)
• Hubitat currently works best as a secondary Matter controller via multi-admin.
• Some Matter device types and features may not yet be fully exposed in Hubitat’s UI.
• Hubitat does not currently bridge non-Matter devices into Matter.

 

Additional information

Weight 40 g
Dimensions 51 × 26 × 24 mm
Gang count

1-gang, 2-gang, 3-gang, 4-gang
Knob colour

Antique Brass, Black, Chrome, Gold, Grey, Metal White, Plastic White, Silver
Brand

Samotech

Frequently Asked Questions

How does the SM323 Matter dimmer differ from the original SM323 Zigbee dimmer?

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.

Which smart home platforms work with the SM323 Matter dimmer?

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.

Do I need a Thread Border Router to use the SM323 Matter dimmer?

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.

Does the SM323 Matter dimmer require a neutral wire?

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.

What load can the SM323 Matter dimmer handle?

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.

Will the SM323 Matter dimmer keep working if my internet is down?

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.

Can I disable dimming on the SM323 Matter and use it just as an on/off switch?

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.

Can the SM323 Matter be used in decoupled or smart-bulb mode?

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.

Are the SM323 Matter faceplates and knobs metal or plastic?

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.

When wired using only the live wire, lights flicker at full brightness. What should I do?

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.

My lights remain faintly lit even when turned off. How do I fix this?

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.

How do I factory reset the SM323 Matter dimmer if the reset button is inaccessible?

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.

Technical Data

SPECIFICATIONS

Manufacturer SAMOTECH / Sunricher
Part number SM323-MT-SL-DIM
Item weight 30 g
Product dimensions 51 × 26 × 24 mm
Type Trailing edge dimmer
Protocol Matter over Thread
Input voltage 230 VAC
Compatibility Apple Home (HomeKit)
Google Home / Nest
Amazon Alexa
Samsung SmartThings
Home Assistant
Hubitat
Light control Push (On/Off), Rotary (Dimming)
Frequency 2.4 GHz
Max LED wattage 175 W
Max incandescent load 350 W
Max halogen load 350 W
Wiring requirements Live only or Live + Neutral
Switch type 2-way

Manual

SAMOTECH SM323 Matter-Over-Thread dimmer manual

Pre-install Checklist

Pre-install checklist for SM323 Matter over Thread

• Confirm you have at least one configured Thread Border Router that is powered on and nearby.
• Keep the Matter QR code or setup code safe until commissioning is complete. We recommend taking a photo and saving it.
• Update your controller app (Apple Home, Google Home, Hubitat, Home Assistant) to the latest version.
• If reinstalling or moving the dimmer, perform a factory reset before re-pairing.
• Avoid installing in deep metal back boxes where possible, as they can reduce Thread signal strength.

Checklist: Before sharing the SM323 to other Matter controllers

• Ensure the dimmer is fully working in the primary Matter controller first.
• Use the primary controller’s built-in Share / Add accessory option (Matter multi-admin).
• Do not factory reset the device when adding additional controllers.
• Allow a few minutes after sharing for the new controller to sync and populate controls.

Bulbs Compatibility Matrix

BULB / LOAD TYPE COMPATIBILITY RISK LEVEL TYPICAL SYMPTOMS RECOMMENDATION
SAMOTECH Dimmable GU10 SAMOTECH GU10 Compatible None None Recommended
Incandescent / Halogen Incandescent Halogen Compatible None None Recommended
Dimmable LED (Quality brands) Quality LED bulbs Compatible None None Recommended
Dimmable LED (Cheap / unknown) Cheap LED bulbs Conditional Very Low Minor flicker. May not turn off fully. Test first. Use a bypass if required.
Low load LEDs (<15W) Low load LED bulbs Conditional Very Low Minor flicker. May not turn off fully. Use a bypass
LED strips (220V dimmable driver) LED strip dimmable Conditional Medium Minor flicker Test first
Integrated LED fittings (separate LED driver, colour modes) Integrated LED fitting Conditional Medium Flashing or intermittent operation due to internal LED driver control Test first
Non-dimmable LED Non dimmable LED Not compatible High Flicker, overheating Do not use with dimmers
Smart bulbs Smart bulb Not compatible High Disconnects, rebooting Do not use with dimmers
LED strips (220V non-dimmable driver) Non dimmable LED strip Not compatible High Flicker, overheating Do not use with dimmers
Fluorescent / CFL CFL bulb Not compatible High Failure to start Do not use with dimmers

13 reviews for Matter Dimmer Switch – Push/Rotary, No Neutral, HomeKit, Alexa & SmartThings (SM323-MT)

4.6
Based on 10 reviews
5 star
80
80%
4 star
10
10%
3 star
10
10%
2 star
0%
1 star
0%

Customer Images

Image #1 from Alex
Image #1 from Alex

Alex

Straightforward good quality switch - love the inclusion of Thread. Easy to setup with Apple Home via Matter.

(2) (0)
Image #1 from Alex
1-10 of 10 reviews
  1. NEIL
    Verified owner

    In reality the depth of these switches can only be comfortable connected in a 47mm box/enclosure, dependent on wiring method/ how busy the switch is.

    (0) (0)
  2. Richard Neal
    Verified owner

    Excellent device, easy wiring, easy pairing, quiet relays, does exactly what it says on the tin.

    (0) (0)
  3. Anonymous
    Verified owner

    Seems good

    (0) (0)
  4. David Georgiou
    Verified owner

    very easy to fit and they’ve worked great so far! customer support is also quick and very helpful!

    (0) (0)
  5. Anonymous
    Verified owner
    (0) (0)
  6. Chris Horton
    Verified owner
    (0) (0)
  7. Dave F.
    Verified owner

    The switch was easy to install and connection to my smart home device was simple.

    (0) (0)
  8. Alex
    Verified owner

    Straightforward good quality switch – love the inclusion of Thread. Easy to setup with Apple Home via Matter.

    Image #1 from Alex
    (2) (0)
  9. Michael
    Verified owner

    Compact easy to install, cames with power management. Connected to my homey hub. The only thing it can’t do, but this may be user error or is not being exposed by homey is to convert the switch into a virtual switch for controlling smart bulbs. All in all, good quality product.

    (0) (0)
  10. Adam S.
    Verified owner

    Great dimmer switch. It’s been reliable so far and works perfectly with my apple Home setup. Dimming and switching the lights with siri works exactly as I expected it. The video was really helpful for understanding the no-neutral installation, and I had everything set up in less than 15 minutes. I’ll definitely be replacing my other dumb dimmers with this one later this year. I do wish it were a bit cheaper though, but there doesn’t really seem to be a any alternative anywhere.

    (0) (0)
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