Smart thermostat guide
Honeywell Home X7S Smart Thermostat X7SMC4B (Black)
24 VAC systems up to 2H/2C, or heat pumps with electric backup, where room sensors and presence sensing appeal
A 4.3-inch touchscreen Wi-Fi thermostat run through the First Alert app, with Matter, a built-in radar sensor and support for up to 20 XRSENSOR room sensors. It needs a C wire. The manual says X7 models cannot control humidifiers, dehumidifiers or ventilators, and heat pumps must use electric backup.
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Published specifications
- Manual, maker, listing: up to 3H/2C heat pump (electric backup), 2H/2C conventional
- Manual: X7 cannot control humidifier, dehumidifier or ventilator
- Manual: radar sensor and up to 20 XRSENSOR room sensors on X7S only
- Manual: 24 VAC C wire required; Wi-Fi 2.4 and 5 GHz; 2.2 VA max
- Manual and maker: 90 x 133 x 24 mm; 4.3-inch display; heat 40-90°F, cool 50-99°F
- User guide: 2-year limited warranty
Fit and limits
Strengths
- Radar presence sensing and up to 20 room sensors, per the manual
- Stage support agreed by manual, maker page and listing
- Two-year limited warranty in the user guide
Caveats
- Cannot control humidifiers, dehumidifiers or ventilators, per the manual
- Listing says an adapter or voucher is included; the manual calls the adapter optional
- Heat pumps: electric backup only, no gas or oil furnace backup
What this listing is: the black X7S for the US
The X7S is a Honeywell Home Wi-Fi thermostat with a 4.3-inch touchscreen, run through the First Alert app and set up for Matter from the thermostat's menu. This listing's model number is X7SMC4B/W. The X7 series user guide lists X7SMC4B as the black thermostat with dark silver accent for the US, and Honeywell's product page shows SKU X7SMC4B/U.
The installation manual's package list is the thermostat, the UWP wall plate, screws and anchors, and literature, noting that kits may include other accessories. Resideo gives the size as 90 x 133 x 24 mm and Honeywell's page as 3.54 x 5.24 x 0.96 inches, and the manual gives an operating ambient range of 37°F to 102°F.
What separates the X7S from the X7B
The manual covers both X7 models and marks the built-in radar sensor as X7S only. It also says the XRSENSOR wireless room sensors, up to 20 per thermostat, are used with the X7S only, and that the X7B cannot be paired with wireless sensors. The user guide likewise marks room prioritisation as an X7S feature.
Honeywell's X7S page notes that the occupancy and presence features require Auto Away to be enabled, and that the optional room sensors are sold separately; this listing's included components do not name a sensor. The manual's section on sensor priority and motion status applies to the X7S, which is the model that can use them.
Humidity: monitoring only, not control
The listing's air quality bullet talks about maintaining indoor air quality with humidity monitoring, adding that extra HVAC equipment or accessories may be required. The installation manual is plainer: X7 models cannot control a humidifier, dehumidifier or ventilator, and it points to the X8 models for those systems.
Honeywell's page lists indoor humidity and outdoor temperature among the information the X7S displays, and the manual gives humidity sensor accuracy of plus or minus 5 percent RH between 30 and 50 percent at 75°F.
Systems it runs, and the heat pump backup rule
The manual, Honeywell's page and the listing agree on up to 3 heat/2 cool heat pump systems with electric backup and up to 2 heat/2 cool conventional systems. The manual names gas or oil forced air with air conditioning and radiant hot water; it does not work with electric baseboard heat at 120-240 V and does not support S terminals.
In the installer settings the manual lets you pick a heat pump backup type, but says the thermostat only supports electric backup and will warn that it is not compatible if another backup type is chosen. Emergency heat mode is only available when a heat pump with backup heat stages is configured.
C wire and the adapter question
The manual lists 24 VAC power by C wire as required, and Honeywell's page says hardwired with C wire required. If there is no spare wire in the wall and your old thermostat had both Y and G wires, the manual says a THP9045A C-wire adapter can be used; its accessory table lists that adapter as optional and ordered separately.
The listing's bullet says a voucher for a free Honeywell Home C-wire adapter by mail is in the package, while its Included Components field reads C-Wire Adapter. A text search of the installation manual found no mention of a voucher. The listing's two statements differ from each other and from the manual, so confirm with the seller what ships. Wi-Fi is 2.4 or 5 GHz.
Everyday settings and warranty
The manual lists heating setpoints from 40°F to 90°F and cooling from 50°F to 99°F, with adjustable range-stops, fan modes Auto, On and Circulate, auto changeover, Adaptive Recovery, Auto Away or a set schedule, and 2.2 VA maximum power consumption. The user guide adds seven idle-screen styles and colors and Matter setup from the menu.
The X7 series user guide states a 2-year limited warranty and points to resideo.info/US-Warranty-THERMOSTAT for terms, with a printed copy available free from Resideo Customer Care at 1-800-633-3991. Honeywell's X7S product page does not list a warranty length, and we did not read the written warranty itself.
Check the current listing
Confirm the model, included parts and availability before ordering.
Primary sources
- Honeywell Home X7S Smart Thermostat product page and specifications (SKU X7SMC4B/U)
- Resideo X7S & X7B Smart Thermostats Installation and User Manual 33-00769-01
- Resideo X7 Series Smart Thermostat User Guide 33-00748EF-01
Primary sources checked .
Compare with
- Sensi Smart Thermostat ST55
Conventional or heat pump systems up to two stages, on a 2.4GHz network, in the old thermostat's footprint
- Google Nest Thermostat (Charcoal)
Single-stage 24V systems that need a schedule and app control, not multi-stage equipment
- Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US)
120V or 240V electric baseboard, fan-forced convector and radiant ceiling heat in a standard gang box
- ecobee Smart Thermostat Premium with SmartSensor
24 VAC forced-air, heat pump, boiler or PTAC systems, checked first with ecobee's compatibility tool
- Google Nest Learning Thermostat (4th gen) with Nest Temperature Sensor (2nd gen)
Multi-stage 24V systems run through the Google Home app, in homes with or without a C wire
- ecobee Smart Thermostat Essential (EB-STATE7-01)
Simple single-transformer systems with one stage of cooling, on a 2.4GHz network
Side-by-side pages, this model next to: Honeywell Home X8S Smart Thermostat X8VMC8B (Black, no sensor), Honeywell Home X7B Smart Thermostat X7BWF1W (White).