Discontinued

Honeywell Home T9 Smart Thermostat

Compiled by SmartHomeWorkflow Research · Honeywell Home (Resideo) · Thermostats · ~$190 (at time of research (discontinued — remaining-stock pricing is volatile) — never treated as a live price)

Official product page shows 'no longer available for sale' (late 2025, alongside the X8S launch); still purchasable as remaining stock at major retailers. Resideo's store names the X8S as the replacement — but T9 room sensors only 'may' pair with it (Resideo's official FAQ says older RCHTSENSORs won't work and newer ones are attempt-at-your-own-risk). Cloud/app support continues via the First Alert app transition. Discontinued as of late 2025 — you are buying remaining stock with a forced app migration ahead, and it will never get Matter; Matter buyers should look at the X8S or X2S instead.

Compatibility

Ecosystem	Support	The catch
Amazon Alexa	Works	Full support
Google Home	Works	Full support
Apple Home	Works	HomeKit added via free firmware update (Nov 2021) — older press saying 'no HomeKit' is outdated
SmartThings	Works	Cloud-linked service
Home Assistant	Works	Core 'Honeywell Lyric' integration is cloud-polling and needs a Resideo developer API key — real friction; HomeKit Controller integration is the local alternative

Protocols: WIFI

Subscription reality

✓ Works without a subscription: Yes.

No subscription for app control, sensors, or voice integrations

Maintenance reality

Batteries: AAA x2 per room sensor — expect roughly 12 months per set
Cloud dependence: Yes — a server shutdown would degrade or brick this device
App control is cloud-based; HomeKit is the only local-control path. Forced app migration ahead: Honeywell Home app → First Alert by Resideo app, requiring device re-add and utility demand-response re-enrollment. C-wire required but a power adapter is included. WiFi works on 2.4 and 5 GHz.

Who it's for

Households that want room-sensor comfort balancing across all five ecosystems at a clearance price and are comfortable buying an end-of-line product.

Sources & method

honeywellhome.com T9 product page (discontinued banner, SKU RCHT9610WFSW2003/U, ecosystem list, in-box contents) + honeywellstore.com ('DISCONTINUED', X8S named as replacement) — vendor-page research, verified 2026-07-15 · Resideo tech doc 33-00565EFS 'T9 & T10 Apple HomeKit Setup' + honeywellhome.com HomeKit support article; firmware timing Nov 2021 press-reported — vendor-page research, verified 2026-07-15 · home-assistant.io/integrations/lyric (core since 2021.3; T9 incl. room-sensor priority; cloud-polling, developer key required) — vendor-page research, verified 2026-07-15 · First Alert / honeywellhome.com support articles on app migration; official sensor pages (AAA x2, ~1yr, 20 sensors max, 200 ft) — vendor-page research, verified 2026-07-15. 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 →

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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