Honeywell Smart Thermostat Review: Which Model Is Best in 2025?

Honeywell has been making thermostats since 1885, and the Honeywell Home smart thermostat lineup brings that legacy into the connected era. If you’re considering a Honeywell smart thermostat, this review breaks down the key models, their strengths and weaknesses, and which one makes the most sense for your home.

Honeywell Smart Thermostat Lineup Overview

Honeywell Home (the consumer brand, now owned by Resideo) offers several smart thermostat models at different price points:

Model	Price	Best For
Honeywell Home T9	~$170	Multi-room sensing, best overall
Honeywell Home T6 Pro	~$100	Budget-friendly Wi-Fi thermostat
Honeywell Home RTH9585	~$90	Simple Wi-Fi, no frills
Honeywell Home T10 Pro	~$190	Professional/contractor installs

This review focuses on the T9 as the flagship consumer model, with notes on the T6 Pro for budget shoppers.

Honeywell Home T9: The Best Honeywell Smart Thermostat

What Makes the T9 Stand Out

The T9’s biggest differentiator is its Smart Room Sensor system. The thermostat ships with one included sensor and supports up to 20 additional sensors placed throughout your home. Each sensor monitors temperature and occupancy, and the T9 uses this data to:

• Focus comfort where you are — It can prioritize heating or cooling the rooms that are currently occupied
• Reduce hot and cold spots — A common problem in Florida homes where the master bedroom and kitchen run at very different temperatures
• Create room-specific schedules — Cool the living room during the day and the bedrooms at night

For larger Florida homes with multiple zones or notoriously uneven temperatures, the Smart Room Sensor system is genuinely useful rather than a marketing gimmick.

Design and Display

The T9 has a 3.5-inch color touchscreen with a clean, readable interface. It’s not as stylish as the Nest Thermostat’s minimal aesthetic, but it’s modern and easy to read across a room. The menu structure is logical once you’ve spent a few minutes with it.

Smart Home Compatibility

The T9 works with:

• Amazon Alexa — Full control via voice
• Google Assistant — Full control via voice
• Samsung SmartThings — Deep integration for automation
• Apple HomeKit — Supported (unlike some Honeywell models)

It does not support Matter natively as of 2025, but broad compatibility with all four major platforms means you’re covered regardless of which ecosystem you use.

Resideo App

The companion app is called Resideo (previously Honeywell Home). It’s functional but not the most polished experience on the market:

• Remote temperature control works reliably
• Schedule creation is straightforward
• Room sensor management is intuitive once set up
• Energy reports show HVAC runtime but lack the detail of Nest or ecobee apps
• Geofencing is available but less refined than Nest’s implementation

The app does what you need it to do, but users who’ve experienced the Google Home or ecobee apps may find the Resideo interface feels dated.

Installation

Installation follows the standard smart thermostat process:

1. Turn off HVAC at the breaker
2. Remove old thermostat and note wiring
3. Install T9 base plate with included hardware
4. Connect wires to labeled terminals
5. Snap on the display and restore power
6. Complete setup in the Resideo app

The T9 requires a C-wire (common wire) for reliable operation. Many Florida homes have this — it’s the wire that provides constant 24V power to keep the thermostat’s Wi-Fi running. If yours doesn’t, the T9 includes a C-wire adapter kit, or you can use a Honeywell power adapter.

Compatibility check: Honeywell’s website has a compatibility checker. Most single-stage and two-stage central HVAC systems work fine. Heat pumps are supported with proper wiring.

Honeywell Home T6 Pro: The Budget Smart Pick

At around $100, the T6 Pro offers Wi-Fi connectivity and remote control without the room sensor system. It’s a solid choice if:

• You have a smaller home or apartment where temperature is consistent throughout
• You primarily want remote control and scheduling without extra complexity
• You’re looking for a budget-friendly upgrade from a basic programmable thermostat

The T6 Pro works with Alexa and Google, has a simple touchscreen display, and uses the same Resideo app as the T9. It doesn’t support Apple HomeKit or Smart Room Sensors.

How Honeywell Compares to Nest and ecobee

Feature	Honeywell T9	Google Nest Thermostat	ecobee SmartThermostat
Room sensors	Yes (included)	No (Nest Learning only)	Yes (included)
Auto-learning	No	Nest Learning only	No (schedule-based)
Apple HomeKit	Yes	No (standard model)	Yes
Price	~$170	~$130	~$200
App quality	Good	Excellent	Excellent

The T9 punches above its weight when it comes to room sensor value — you get one included and don’t need to spend extra to get multi-room sensing like you would with ecobee.

Real-World Energy Savings

In Florida’s climate, where HVAC systems run heavily from April through October, a smart thermostat can deliver meaningful savings. Honeywell’s own data suggests 10-23% savings on heating and cooling costs, depending on your previous habits.

The T9’s room sensor approach can add additional savings by not over-cooling unoccupied spaces — relevant for larger Florida homes where the main living area and bedrooms may have very different usage patterns throughout the day.

Pros and Cons

What we like:

• Included room sensor is a genuine value advantage
• Works with all major smart home ecosystems including HomeKit
• Reliable hardware with Honeywell’s long track record
• Good compatibility with a wide range of HVAC systems

What could be better:

• Resideo app feels less polished than competitors
• No auto-learning (you set the schedule manually)
• No Matter support
• Bulkier design than Nest

Final Verdict

The Honeywell Home T9 is an excellent smart thermostat for homeowners who want multi-room temperature control without paying ecobee prices. Its compatibility with all major smart home platforms and the included Smart Room Sensor make it a compelling choice — particularly in larger Florida homes where temperature consistency across rooms is a real challenge. If you’re on a tighter budget, the T6 Pro offers solid Wi-Fi thermostat functionality at a lower price point.