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Smart thermostat guide

Honeywell Home ElitePRO S1200 Smart Thermostat THX1200B6 (Black)

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Professionally installed systems up to 4H/2C heat pump or 3H/3C conventional, with IAQ equipment

Resideo's trade-channel 5-inch touchscreen thermostat with Redlink 3.0 sensors, IAQ control for up to two devices, doorbell video and Matter. Honeywell says it requires a pro for installation and warranty, and the user guide says the 5-year warranty may be void without professional installation.

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Published specifications

  • Maker and listing: up to 4H/2C heat pump or 3H/3C conventional
  • Maker: dual fuel, fan-coil, PTAC and radiant compatible; optional EIM
  • Maker: hardwired, C wire required; guide: THP9045A adapter sold separately
  • Guide: BLE, Wi-Fi 2.4 and 5 GHz, Redlink 900 MHz, radar 61.5 GHz
  • Maker: 3.54 x 5.25 x 0.96 in; 5-inch touchscreen; IAQ up to 2 devices
  • User guide: 5-year limited warranty, may be void without pro install

Fit and limits

Strengths

  • Supports up to 4H/2C heat pump or 3H/3C conventional systems
  • Controls up to two IAQ devices and reads humidity, VOC and estimated CO2
  • Five-year limited warranty, per Honeywell and the user guide

Caveats

  • Trade product: warranty may be void if not professionally installed
  • Installer guide says a trained HVAC professional must install it
  • Listing's Model Number field names the white THX1200W5

A professional-channel thermostat sold on Amazon

The ElitePRO S1200 is a Resideo trade thermostat under the Honeywell Home name. Honeywell's product page says it requires a pro for pricing, installation and warranty. The user guide states that it is a trade product and that the 5-year limited warranty may be void if it is not installed by a professional.

The installer guide carries a warning that the product must be installed by a trained, experienced HVAC professional. If you were planning a do-it-yourself install, read the warranty condition first; we do not give wiring or setup steps here.

Which version this listing is

The listing's title and manufacturer part number are THX1200B6, and Honeywell's page shows SKU THX1200B6/U, the black S1200. Both Resideo guides list THX1200B6 as the black S1200 thermostat. The listing's separate Model Number field reads THX1200W5, which the same guides list as the white S1200.

The installer guide's package list is the thermostat, the UWP wall plate, a decorative cover plate with J-box adapter, screws and anchors, and literature. Honeywell lists the thermostat at 3.54 by 5.25 by 0.96 inches; the listing gives 5.24 inches wide. Kits sold with an equipment interface module (EIM) use different part numbers, and the guide says those cannot be wired without the EIM.

Stages, systems and the EIM

Honeywell's page and the listing say the S1200 works with systems up to 4 heat/2 cool heat pump or 3 heat/3 cool conventional, and is compatible with dual fuel, fan-coil, PTAC and radiant systems. Modes are heat, off, cool, auto and emergency heat.

Both sources list an optional equipment interface module (EIM). The installer guide shows two common wiring layouts without the EIM, a 2 heat/2 cool gas furnace and a heat pump with auxiliary heat, and points to online documentation for the rest. Wiring details are for the installer; we do not reproduce them.

Power and the C wire

Honeywell's page lists the power source as hardwired with a C wire required. The installer guide says that where there is no C wire or spare wire and the old thermostat used both Y and G wires, the THP9045A C-wire adapter, sold separately, may be used.

The installer guide gives the thermostat input power rating as 24 V, 60 Hz, 2.6 VA in its wiring section, and lists input ratings of 24 V, 60 Hz, 0.11 A in its specifications. It lists Bluetooth Low Energy, dual-band 2.4 and 5 GHz Wi-Fi, Redlink at 900 MHz and radar at 61.5 GHz.

Air quality, sensors, doorbell view and app

Honeywell's page says the S1200 can control up to 2 IAQ devices and monitors indoor humidity, VOC and estimated CO2. It lists Redlink 3.0 for wireless room sensors, the EIM and outdoor sensors, and names the C7189R3010 room sensor among its accessories.

The user guide covers the First Alert by Resideo app, room priority, humidity and ventilation menus when IAQ control is configured, live video from First Alert VX1 or Ring doorbells, and Matter. Heat setpoints run from 40°F to 90°F and cool from 50°F to 99°F unless an installer has set range-stops.

Warranty terms in plain terms

The user guide states a 5-year limited warranty and adds that, as a trade product, the warranty may be void if it is not installed by a professional. It points to resideo.info/US-Warranty-THERMOSTAT for terms and says Resideo Customer Care at 1-800-633-3991 will mail a printed copy free of charge.

Honeywell's page lists the warranty as 5 years and the listing's warranty field also says 5 years. Neither the page nor the listing repeats the professional-installation condition. We did not read the written warranty itself.

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Primary sources

  1. Honeywell Home ElitePRO S1200 Smart Thermostat product page and specifications (SKU THX1200B6/U)
  2. Resideo ElitePRO S1100 & S1200 Smart Thermostat Installer Guide 33-00706EF-02
  3. Resideo ElitePRO S1200 Smart Thermostat User Guide 33-00708EF-01

Primary sources checked .

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