Honeywell Home YTHX1200W7/U ElitePRO S1200 Thermostat, White w/EIM

The Honeywell Home ElitePRO S1200 is the line's top pro-grade smart thermostat, sold here in white under part number YTHX1200W7/U. This kit packs the thermostat plus an Equipment Interface Module (EIM). It replaces an existing thermostat on the wall and runs heating, cooling, fan, and indoor air quality from one 5-inch touchscreen you can recolor to suit the room.

It fits most residential and light commercial systems: up to 4 stages of heat and 2 of cool on a heat pump, or 3 heat / 4 cool conventional. That covers dual fuel, gas, oil, and electric warm air, hydronic, 2- and 4-pipe fan coil, PTAC, and radiant floor. The thermostat is hardwired on 24 VAC and needs a C-wire; if you don't have one, add the THP9045A C-wire adapter (sold separately).

What sets the S1200 apart is the air-quality and doorbell side. It reads indoor humidity, VOCs, and estimated CO2, senses occupancy with onboard radar, and streams video from First Alert and Ring doorbells so you can see and speak to visitors from the wall. 0 links remote room and outdoor sensors, and you manage it from the First Alert app over dual-band Wi-Fi, Bluetooth, and Matter, with Amazon Alexa, Google Home, and Apple Home.

ENERGY STAR certified and rebate-eligible. In the box: the ElitePRO S1200 thermostat, an Equipment Interface Module (EIM), the UWP wall plate, and a white cover plate with J-box adapter (THP2400WH). Honeywell part number YTHX1200W7; orderable YTHX1200W7/U.

This white kit's siblings are separate listings: the black EIM kit, the EIM and room-sensor versions, and the bare thermostat. Replaces THX9421R5021WW/U, YTHX9421R5101WW/U and other Prestige IAQ kits, plus YTHM1004R3024/U, YTHM1004R3000/U, YTHM1004R3001/U. 96 in D (133 x 90 x 24 mm).