Product Library / Thermostats

Research profile · last verified 2026-09-01

Honeywell Home X8S Smart Thermostat

Compiled by SmartHomeWorkflow Research · Honeywell Home (Resideo) · Thermostats · ~$219.99 (at time of research ($249.99 with one room sensor) — never treated as a live price. Corrected 2026-08-07 from a rounded 220 to the published 219.99.)

Compatibility at a glance

Does it work with your platform?

Choose your platform to see its setup and functions. Your choice carries across product pages.

[2][7][18][25][27]
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[7][18][27]
[7][19][27]

A connection can work while individual controls or automations remain unconfirmed. Read the connection details ↓

Protocols: WIFI · MATTER[3][6][13]

Before you buy

What do you need to make it work?

No hub for the device alone

Choose a platform above for its connection. A hub can be optional for the device itself and required for a platform or automation.

One device can provide more than one role. These are setup requirements, not a shopping list of separate purchases.

What could you do with this?

Put its functions to use.

Research, not hands-on testing

Start with a documented control or event. The selected connection shows what is confirmed for that platform.

Documented device function

Target temperature

The device supports this control.

Compare its platform availability in the table below.

Setup and sources

Device documentation: [11]

Documented device function

HVAC mode

The device supports this control.

Compare its platform availability in the table below.

Setup and sources

Device documentation: [11]

Documented device function

Temperature reading

The device reports this event.

Compare its platform availability in the table below.

Setup and sources

Device documentation: [11]

A documented control or event is one part of a setup. It does not by itself establish a complete automation.

The functions, side by side

What can you use, and where?[11]

A platform connection does not confirm every function. Controls and reported events are shown separately from what an automation can use.

Controls
2 documented
Reported events
1 documented

Compare all five platforms. On a narrow screen, scroll the table sideways.

Documented device functions, platform controls and automation availability
Device functionApple HomeWorks[2][7][18][25][27]Google HomeWorks[2][7][18][25][27]AlexaWorks[2][7][18][25][27]SmartThingsWorks[7][18][27]Home AssistantWorks[7][19][27]
Target temperatureDevice control
Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

? not stated

Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

—

HVAC modeDevice control
Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

? not stated

Control

Supported for this Matter device type

Automation

✓ routines can use it

Control

Supported for this Matter device type

Automation

—

Temperature readingReported event
Event

Supported for this Matter device type

Automation

✓ routines can use it

Event

Supported for this Matter device type

Automation

✓ routines can use it

Event

Supported for this Matter device type

Automation

? not stated

Event

Supported for this Matter device type

Automation

✓ routines can use it

Event

Not stated

Automation

—

✓ Documented for this connection. × A stated limit. ◐ A partial function. ? Not established. A listed device function does not establish a complete routine, its other equipment or any plan requirements.

Matter device-type support is based on the platform’s list for this kind of device; this exact model is not named.

Setup and sources

Apple Home

Matter only — no native HomeKit certification; an iPhone on iOS 18 or later can add and control it over Matter without a home hub, and a HomePod, HomePod mini or Apple TV is still needed to control it away from home, run automations and share control.[2][7][18][25][27]

Google Home

Matter only; basic thermostat control[2][7][18][25][27]

Alexa

Matter only — no native Alexa skill documented for the X-series; Matter exposes temp/setpoint/mode, not schedules or air quality[2][7][18][25][27]

SmartThings

Works as a generic Matter device rather than a named partnership: as of 2026-08-07 Resideo's own product page and its retail listings name Alexa, Google and Apple Home but never SmartThings, so the path is Matter certification plus SmartThings being a Matter controller, corroborated by press testing rather than by any Resideo statement[7][18][27]

Home Assistant

Home Assistant sets the temperature and switches heating and cooling modes through its own Matter support, which runs locally. Resideo marks the X8S as Matter certified but does not name Home Assistant. Schedules and air-quality readings stay in the First Alert app, and Home Assistant's older Honeywell cloud integration does not cover the X-series.[7][19][27]

Platform documentation:

honeywellhome.com · checked 2026-10-07

Apple Home — Matter path · checked 2026-09-04

Google Home — Matter path · checked 2026-10-03

Alexa — Matter path · checked 2026-09-04

SmartThings — Matter path · checked 2026-10-07

home-assistant.io · checked 2026-09-01

Apple Home — Matter path · checked 2026-10-03

SmartThings — Matter path · checked 2026-10-14

SmartThings — Matter path · checked 2026-10-14

SmartThings — Matter path · checked 2026-10-14

SmartThings — Matter path · checked 2026-10-14

Home Assistant — Matter path · checked 2026-10-04

Device documentation: [11]

Listed device functions are established from vendor documentation. An ability missing here is unestablished, not necessarily absent.

Connection details and setup sources
EcosystemSupportThe catch
Amazon AlexaWorksWorks with this ecosystem[2][7][18][25][27]Matter only — no native Alexa skill documented for the X-series; Matter exposes temp/setpoint/mode, not schedules or air qualityIn Amazon Alexa you also need: a Matter-capable Amazon Echo or eero device — Alexa’s rule for every Matter accessory. Source (read 2026-09-11)
Google HomeWorksWorks with this ecosystem[2][7][18][25][27]Matter only; basic thermostat controlIn Google Home you also need: a hub for Google Home (a Nest speaker or display, Nest Wifi Pro, the Google TV Streamer, or a compatible TV) — Google Home’s rule for every Matter accessory. Source (read 2026-09-11)
Apple HomeWorksWorks with this ecosystem[2][7][18][25][27]Matter only — no native HomeKit certification; an iPhone on iOS 18 or later can add and control it over Matter without a home hub, and a HomePod, HomePod mini or Apple TV is still needed to control it away from home, run automations and share control.
SmartThingsWorksWorks with this ecosystem[7][18][27]Works as a generic Matter device rather than a named partnership: as of 2026-08-07 Resideo's own product page and its retail listings name Alexa, Google and Apple Home but never SmartThings, so the path is Matter certification plus SmartThings being a Matter controller, corroborated by press testing rather than by any Resideo statementIn SmartThings you also need: a Matter-compatible SmartThings hub — SmartThings’s rule for every Matter accessory. Source (read 2026-10-14)
Home AssistantWorksWorks with this ecosystem[7][19][27]Home Assistant sets the temperature and switches heating and cooling modes through its own Matter support, which runs locally. Resideo marks the X8S as Matter certified but does not name Home Assistant. Schedules and air-quality readings stay in the First Alert app, and Home Assistant's older Honeywell cloud integration does not cover the X-series.In Home Assistant you also need: Home Assistant's own Matter Server app, installed from inside Home Assistant (no extra hardware to buy) — Home Assistant’s rule for every Matter accessory. Source (read 2026-09-11)

Plans and ongoing costs[2][25]

✓ Works without a subscription: Yes.

Vendor account required: Inconclusive — we read the vendor's own setup material and it does not say either way. Treat it as unanswered rather than as a no.

No paid tier found in any official or press source; whether Ring doorbell live view needs Ring's own subscription is unaddressed by Resideo

Maintenance and offline use[1][3][4][5]

The catch

Matter exposure is minimal — temperature, setpoint, and mode only, with schedules and all air-quality data locked to the First Alert app; a Resideo account is required before Matter pairing; a C-wire is required to power it, though Resideo ships a voucher for a free C-wire adapter that works if your old thermostat had both Y and G connected; and T9 room sensors probably won't carry over (budget $45/room for XRSENSORs).

Who it's for

Households that want a big-screen flagship with room sensors, air-quality readouts, and doorbell live view, and are happy running the First Alert app with basic-control Matter tie-ins to any ecosystem.

Check availability at Honeywell Home (Resideo)

This opens Honeywell Home (Resideo)'s own website. We earn nothing from this link.

Sources & method

Numbered sources below back the facts marked with the matching number above. This is a research profile: compiled from manufacturer documentation, certification registries, and published testing — we state facts, not verdicts, and we have not physically tested this unit. How we work →

30 numbered sources· read them in the source's own words
  1. [1] Resideo, X8S & X8Q installation guide (retail installation section) — Read on the maker's own site, verified 2026-08-07
    Backs: Batteries, Works without the internet
  2. [2] Resideo, Honeywell Home X8S product page — Read on the maker's own site, verified 2026-08-07
    Backs: Product identity, Price, Subscription, Market availability, Amazon Alexa compatibility, Apple Home compatibility, Google Home compatibility
  3. [3] Resideo, X8S & X8Q specifications — Read on the maker's own site, verified 2026-08-07
    Backs: Batteries, Works without the internet, Protocols
  4. [4] Resideo, XRSENSOR wireless room sensor listing + X8S FAQ — Read on the maker's own site, verified 2026-08-07
    Backs: Batteries, Works without the internet
  5. [5] Resideo newsroom launch release (Dec 3 2025) + honeywellhome.com X8S product/spec pages + docs.honeywellhome.com X8S user guide (FAQ, sensors, doorbell, battery) — Read on the maker's own site, verified 2026-07-15
    Backs: Batteries, Works without the internet
  6. [6] CSA certified-products database: 'ElitePRO/X8/X7 Smart Thermostat' CSA2552FMAT46209-24 (Matter 1.4, WiFi transport, cert 2025-07-25; family record under pro SKUs — no record keyed to retail X8VWF/X8VMC SKUs found) — Checked a certification register, verified 2026-07-15
    Backs: Protocols, Product identity
  7. [7] Official docs describe Matter QR pairing as the only smart-home path; Matter Alpha hands-on review ('minimal Matter support': temp/setpoint/mode only, no air quality via Matter; SmartThings and Homey tested working); HA exposure verified by community on sibling X2S — Checked a certification register, verified 2026-07-15
    Backs: Amazon Alexa compatibility, Google Home compatibility, Apple Home compatibility, SmartThings compatibility, Home Assistant compatibility
  8. [8] Honeywell Home store, X8S Smart Thermostat product record — Read on the maker's own site, verified 2026-08-11
    Backs: Product identity, Price, Market availability, Service status
  9. [9] Resideo / Honeywell Home own-domain search for a published support period — three likely addresses do not exist; the disclosure programme and the per-product end-of-support notices are what exists instead, verified 2026-08-11
  10. [10] docs.honeywellhome.com X8S installation-and-user-guide specification page, re-read 2026-08-18, plus the cited honeywellhome.com product pages — Read on the maker's own site, verified 2026-08-18
  11. [11] honeywellhome.com/products/x8s-smart-thermostat, read 2026-08-20: "Control from anywhere using the First Alert app"; compatible with "Amazon Alexa, Google Assistant, Apple Home"; "Matter certified"; features list includes "Onboard Radar Sensor" and a display carrying "Indoor Humidity; Outdoor Temperature; Time; Current Setting; Current Temperature". The CSA certified-products database carries "ElitePRO/X8/X7 Smart Thermostat", certificate CSA2552FMAT46209-24 (Matter 1.4, WiFi transport, certified 2025-07-25) — the family record this product's Matter support is established on, already cited on this record for its protocols and its identifiers. — Read on the maker's own site, verified 2026-08-20
    Backs: Capabilities
  12. [12] honeywellhome.com's X8S product page, read 2026-08-20. The published requirement is a router, not a hub: "2.4 or 5.0 GHz WiFi; 802.11ax/ac/a/b/g/n wireless router". Platforms: "Matter certified and also compatible with Amazon Alexa, Google Assistant, Apple Home." In-box lists by variant: "X8S Smart Thermostat; UWP® wall plate; Screws and Anchors; Literature" and, on sensor variants, "X8S Smart Thermostat; Wireless indoor sensor; UWP Wall Plate; Screws and Anchors". — Read on the maker's own site, verified 2026-08-20
    Backs: Required hub or bridge
  13. [13] This record's existing per-model Matter evidence, re-read 2026-08-20 against the settled definition of what counts as a protocol: certificate CSA2552FMAT46209. No new outside page was opened — the evidence already on this record was re-examined and this entry states what it establishes., verified 2026-08-20
    Backs: Protocols
  14. [14] Three Resideo first-party surfaces, all read 2026-08-20 and none carrying a support period. (1) resideo.com/us/en/support/security/ publishes no defined support duration, no end-of-support policy and no per-model timeframe. (2) The Resideo responsible-disclosure page describes its Coordinated Vulnerability Disclosure process and PSIRT investigation, and commits to no timeline for patch availability and no duration of support. (3) Resideo's two published end-of-support announcements are the informative part: the legacy Wi-Fi Water Leak Detectors ended installation support because "The security certificates used by these devices have expired" and "the certificates cannot be updated", with devices not online as of January 12, 2026 no longer installable; and the Honeywell Home Smart Security Kit ended October 31, 2024 because a certificate "was created and maintained by Honeywell" and Honeywell chose not to renew it. — Read on the maker's own site, verified 2026-08-20
    Backs: Security-update support period
  15. [15] Resideo's own X8S product page, re-read 2026-08-27 openly, identifying ourselves, after checking the site's own rules for automated readers (which allow it): 19,115 characters of text. ZERO occurrences of 'sign in', 'sign up', 'account is required' or 'requires an account'. The page names the First Alert App as the control surface — 'Control from anywhere using the First Alert app' — and states no account requirement for it. The only 'register' on the page is the site's own 'Register Your Product' navigation link. The record's other cited source, the installation document, mentions an account exactly once and this record already says it is not an answer: 'registered to account' is stated about the CLOCK, not about heating. — Read on the maker's own site, verified 2026-08-27
  16. [16] Record-keeping entry: the migrated research stamp was retired from this record on 2026-08-30, verified 2026-08-30
  17. [17] The structured product data behind honeywellhome.com/products/x8s-smart-thermostat, read 2026-09-01: title "X8S Smart Thermostat", four variants, all available — X8VMC8B/U black $219.99 · X8VWF7W/U white $219.99 · X8VMC9W/U with room sensor, white $249.99 · X8VWF10B/U with room sensor, black $249.99. — Read on the maker's own site, verified 2026-09-01
    Backs: Product identity, Price, Market availability
  18. [18] honeywellhome.com/products/x8s-smart-thermostat, re-read 2026-09-01. The page's works-with statements name, verbatim, "Amazon Alexa", "Google Home" and "Apple Home", and describe the product as "Matter certified". Remote control is attributed to the First Alert app: "Control from anywhere using the First Alert app". Samsung SmartThings is named nowhere on the page. — Read on the maker's own site, verified 2026-09-01
    Backs: Amazon Alexa compatibility, Google Home compatibility, Apple Home compatibility, SmartThings compatibility
  19. [19] home-assistant.io/integrations/matter/, re-read 2026-09-01. IoT class "Local Push"; "Climate" is among the supported categories. On feature coverage the page states, verbatim: "Matter, being a universal standard, might not have the nitty-gritty features that come with a product-specific protocol", illustrated with Hue, where "the communication over Matter only provides the basic controls over lights, while the official Hue integration brings all Hue unique features". — Read the platform's own documentation, verified 2026-09-01
    Backs: Home Assistant compatibility
  20. [20] docs.honeywellhome.com/x8s-iug/Specifications.htm (Resideo's own X8S/X8Q installation and user guide), re-read 2026-09-01. Verbatim rows: "Dual-Band Wi-Fi: 2.4 & 5GHz" · powering method "Common wire required" · "20-30 VAC" · "Power Consumption: 3.0 VA MAX" · "Bluetooth: BLE 2.4 GHz" · "Wireless Communication to XRSENSOR Indoor air sensors: 900 MHz" · "Radar: 61.5 GHZ". — Read on the maker's own site, verified 2026-09-01
    Backs: Wi-Fi bands it can use, Power source
  21. [21] home-assistant.io/integrations/matter/, read 2026-09-01, IoT class "Local Push", establishing that Matter control of a certified device is a local transport. honeywellhome.com/products/x8s-smart-thermostat, read the same day, describes the product as "Matter certified" and attributes remote control and scheduling to the cloud app: "Control from anywhere using the First Alert app", which "enables control of your Smart Thermostat" and lets users "set schedules to help save on energy". — Read on the maker's own site, verified 2026-09-01
    Backs: Works without the internet
  22. [22] This record's own scheduled re-verification of 2026-09-01: honeywellhome.com/products/x8s-smart-thermostat and the structured product data behind it, docs.honeywellhome.com/x8s-iug/Specifications.htm, docs.honeywellhome.com/x8s-iug/Retail/Installation.htm, and home-assistant.io/integrations/matter/ — all read in full on the day of the stamp. The installation guide re-confirms verbatim: "Resideo Wi-Fi thermostats requires a C-wire to power the display" and "If there is no extra wire available and both the Y and G wires were connected on the previous thermostat, you can use a THP9045A C-wire adapter." — Re-checked this against its sources, verified 2026-09-01
    Backs: Research status, Service status
  23. [23] this record's own lifecycle note as it stood before 2026-09-17 (no new external read): its wording was rewritten so it reads in plain language. No fact, date, source or value changed, and the earlier wording is kept on this record., verified 2026-09-17
  24. [24] Honeywell Home's own US store listing for the X8S Smart Thermostat, read 2026-09-18. The listing is titled "X8S Smart Thermostat", is sold by Honeywell Home, and names its versions by the same order codes this record already carries: X8VMC8B/U (X8S Smart Thermostat in Black); X8VWF7W/U (X8S Smart Thermostat in White). — Read on the maker's own site, verified 2026-09-18
    Backs: Certification and product IDs
  25. [25] Resideo, Honeywell Home X8S Smart Thermostat product page, verified 2026-09-21
    Backs: Subscription, Market availability, Service status, Price, Product identity, Amazon Alexa compatibility, Google Home compatibility, Apple Home compatibility, Power source
  26. [26] The Connectivity Standards Alliance's page for Resideo's ElitePRO/X8/X7 Smart Thermostat, read in full on 2026-10-03, lists a Matter certificate (CSA25F8DMAT48863-24, certified 2025-12-10, Wi-Fi, thermostat device type) for family SKU YTHX1200W7/U with variant YTHX1200W5/U, and many sibling certificates under the same name. No SKU on the page matches this product's X8VMC8B/U. — Re-checked this against its sources, verified 2026-10-03
  27. [27] Resideo's X8S product page, read in full on 2026-10-07 (the fingerprint matches change detection's). Verbatim: "Control Remotely: Control from anywhere using the First Alert app - Matter certified and also compatible with Amazon Alexa, Google Assistant, Apple Home" · "Works With Our products, apps and services work in harmony with leading smart home ecosystems. Amazon Alexa Google Home Apple Home". The page names neither SmartThings nor Home Assistant. — Re-checked this against its sources, verified 2026-10-07
    Backs: Amazon Alexa compatibility, Apple Home compatibility, Google Home compatibility, SmartThings compatibility, Home Assistant compatibility
  28. [28] Apple Support, 'Pair and manage your Matter accessories' (Published Date May 07, 2026), read 2026-10-10: "If you have an iPhone using iOS 18 or later, you can add Matter accessories to and control Matter accessories from the Home app without a home hub." · "However, for the best experience set up a home hub to add supported Matter and thread-based accessories to the Home app." — Read the platform's own documentation, verified 2026-10-10
    Backs: Required hub or bridge
  29. [29] Apple Support, 'Set up your HomePod, HomePod mini, or Apple TV as a home hub' (Published Date September 15, 2025), read 2026-10-10: "Set up a home hub to control your smart home accessories while you're away from home, share control of your accessories with others, and automate your accessories to do what you want, when you want." — Read the platform's own documentation, verified 2026-10-10
    Backs: Required hub or bridge
  30. [30] Record-keeping entry: the alexa, google, apple, smartthings, home_assistant answers of this record gained a per-function findings map from the platforms' own Matter files (alexa-matter.json, google-matter.json, apple-matter.json, smartthings-matter.json, home_assistant-matter.json), 2026-10-17, verified 2026-10-17

Compatibility and lifecycle information reflects the last-verified date above and can change without notice (firmware updates, cloud-service changes, discontinuations). It is provided as-is, for information — verify with the manufacturer before purchasing. Spot an error? Tell us and we'll fix it. Full terms: Terms of Service.

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