Eurotronic Comet Matter: Matter over Thread Radiator Thermostat

The Eurotronic Comet Matter is a Matter over Thread radiator thermostat. Eurotronic's German product page and manual call it Comet Zero Matter, article number 700255, while the CSA DCL record names it Comet Matter. It connects over Thread and is CSA-certified. The DCL compliance records list two certificates: CSA25238MAT45450-24 (software 1.1.0, 2025-05-02) and CSA264ZMMAT55874-24 (software 1.4.0, 2026-09-28). The CSA product page still shows the older one, with Specification Version 1.3. Eurotronic lists Alexa, Google, Apple and SmartThings as compatible. MatterCheck's thermostat type matrix also gives Yes for pairing on Home Assistant, Homey and Hubitat.

Comet Matter Thread Transport and CSA Certification Facts

The CSA DCL entry for vendor ID 5489 and product ID 227 lists product name and label as Comet Matter, part number 15710227, and device type 769, which maps to thermostat. The CSA product page shows Certificate ID CSA25238MAT45450-24, firmware 1.1.0, certified date 05/02/2025 (2 May 2025 in the DCL compliance record), Specification Version 1.3. The DCL compliance record for software 1.4.0 adds certificate CSA264ZMMAT55874-24, dated 2026-09-28. Eurotronic's product page describes the radio standard as Matter over Thread V1.4.2. The version differs across sources: the product page says V1.4.2, while the CSA listing says Specification Version 1.3 and an older manual (February 2026) says Matter V1.3.

Because it is a Thread device, this thermostat needs a Thread border router on the fabric plus a Matter controller to join. Eurotronic's product page does not say a border router is included. HomeKits.de writes that it needs no additional hub to enter Apple Home, but any Matter-over-Thread accessory still depends on the Thread border-router role that an Apple Home hub or another border router supplies; see MatterCheck's Matter hub and Thread border router guide. This is different from Wi-Fi-based Matter accessories, as covered in the Thread vs Wi-Fi guide.

Matter Platform Support for Comet Matter Thermostat

These are MatterCheck's type-level matrix answers for thermostats, not product-specific tests of the Eurotronic Comet Matter.

Eurotronic's product page names only Alexa, Google, Apple and SmartThings. The supplied sources do not name Home Assistant, Homey or Hubitat for this exact Comet Matter model, so those rows follow MatterCheck's thermostat type matrix. The Unknown cells are Apple Home and Amazon Alexa for starting automations.

Cross-Platform Comparison for the Comet Matter Matrix

At type level, pairing and control are Yes on all seven platforms. Google Home, SmartThings, Home Assistant, Homey and Hubitat all have Yes for both automation roles. Apple Home and Amazon Alexa are Unknown for starting automations, but Yes for being controlled by automations. That means a Comet Matter added to Apple Home or Alexa should be able to be controlled by an automation there, while a temperature change starting an automation remains Unknown in the matrix.

Product-specific sources are narrower. Eurotronic's page lists Alexa, Google, Apple and SmartThings, and HomeKits.de reports Apple Home availability. There is no Comet Matter-specific Home Assistant, Homey or Hubitat setup report in the supplied pages, so use the type-level Yes as the baseline. Sharing one Thread accessory across several controllers would rely on Matter multi-admin, covered in Matter multi-admin share device; the product page does not provide multi-controller steps.

Comet Matter Setup Steps, Specs, and Reported Limits

Manufacturer-listed specs and box contents

• Eurotronic lists Matter over Thread V1.4.2, 2.4 GHz radio, maximum transmit power +8 dBm.
• Power is two 1.5 V AA/Mignon/LR6 batteries, and two AA batteries are included.
• Valve connection is M30 × 1.5 mm with operation type 1.
• Control range is 8 °C to 28 °C, with 0.1 °C sensitivity and a weekly self-test.
• Eurotronic's product page lists dimensions 60 × 65 × 85 mm and weight 162 g including batteries; HomeKits.de lists dimensions 62 × 68 × 82 mm; the October 2026 manual lists 62 × 68 × 83 mm. Gross package weight is 211 g.
• IP20 rating, white colour, LED display.
• Box includes the Comet Zero Matter thermostat, a quick guide in 10 languages, Danfoss RA, RAV and RAVL adapters, and two AA batteries.
• Article number 700255 and EAN 4260012712612.

What Eurotronic says it can do

• Day-by-day or week-by-week heating and saving times, individually programmable.
• Window-open detection and automatic summer/winter time change.
• Child lock, frost protection and limescale protection.
• Up to 30% heating-cost savings, quiet operation, and Eurotronic valve protection.
• Manual temperature adjustment at any time using the buttons.
• Works with many common radiator valves; additional adapters can be ordered.

Apple Home and Home Assistant notes

HomeKits.de's 21 January 2026 report says the Comet Zero Matter was available via Amazon at €29.99 UVP, then reduced 15% to €25.44 one day later. HomeKits.de says it uses Matter over Thread and needs no extra hub to enter Apple Home. It also lists a temperature LED display, plus and minus buttons, and 0.5 °C temperature steps.

For Home Assistant, Eurotronic's product page does not name the platform. MatterCheck's thermostat matrix gives Home Assistant Yes for pairing, control, automation trigger and automation action, but no Comet Matter-specific Home Assistant setup report appears in the supplied sources.

The October 2026 manual calls it Comet Zero Matter. Its table of contents includes a section "Mit Matter-Netzwerk verbinden" (connect to a Matter network), but the excerpt supplied does not include step-by-step pairing menu names. If pairing fails, MatterCheck's Matter device not pairing guide covers Thread and controller checks.

There is no hands-on review or test of the Comet Zero Matter in the supplied sources; HomeKits.de is a news report about availability, price and basic hardware details. There is also no source in this record for a separate "Comet Wifi Matter" model: the Matter product described is the Thread-based Comet Zero Matter/Comet Matter.

Eurotronic Comet Matter: Buy or Skip

• Buy if you want a Thread-based Eurotronic radiator thermostat with manual buttons, 8–28 °C range, and Danfoss RA/RAV/RAVL adapters included, at €29.99 UVP (reduced to €25.44 per HomeKits.de).
• Buy if you already use Apple Home, Alexa, Google or SmartThings and have a Thread border router; Eurotronic lists those platforms and HomeKits.de reports Apple Home availability.
• Skip if you need product-specific Home Assistant, Homey or Hubitat setup evidence; only MatterCheck's thermostat type matrix covers those platforms, not a Comet Matter-specific report.
• Skip if you want Wi-Fi Matter or no Thread border-router dependency; this device is Matter over Thread.