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White rectangular smart thermostat with smooth finish and subtle display, about six by four inches

Sensi Smart Thermostat

SKU CH-MSF4-EWMBZ

Wi-Fi thermostat with Alexa control and Energy Star certification saves about 23% on HVAC energy

  • Product colorWhite
  • Privacy protected — personal data never sold to third parties
  • Easy DIY install with built-in level and step-by-step app guidance
  • Saves about 23% on HVAC energy via ENERGY STAR certified features
  • Simple configuration fits existing thermostat space without wall repairs
  • Smart maintenance alerts monitor system performance and remind filter replacement

Smart thermostat with Wi-Fi and Energy Star

The Sensi ST55 is a white smart thermostat designed for residential heating and cooling systems. It connects to a 2.4 GHz Wi-Fi network for remote control and monitoring. Energy Star certification indicates the device can help reduce HVAC energy use by about 23 percent. The unit includes a built-in level for straight mounting.

Check HVAC wiring and Wi-Fi band before ordering

Most installations do not require a common wire, but the thermostat can be powered by battery or a C-wire if present. Verify that the existing equipment is compatible with the wiring terminals on this model. The home network must broadcast a 2.4 GHz signal because the thermostat does not support 5 GHz bands. The wall opening should accommodate the 5.875 by 3.75 inch footprint.

Fits standard thermostat locations

The thermostat occupies the same footprint as a traditional unit so patching and painting are unnecessary. Physical buttons and a backlit display provide local control without a phone. Remote access, usage reports and smart maintenance alerts are delivered through the companion app. Privacy protection means personal data is not sold to third parties.

How it compares

Measured against everything we stock in Thermostats & Thermostat Accessories, at today’s prices. Recalculated every night.

Price $117.99
Pricier than about 69% of the 286 comparable items (median $78.49).

Specifications

Product
Brand nameSensi
Product colorWhite

Questions about this item

Does the ST55 thermostat include a C-wire adapter or must one be purchased separately?

The ST55 works with most HVAC systems without a common wire, so a separate C-wire adapter is not required for typical installations.

Which model should I choose between the Sensi Wi-Fi Thermostat and the Sensi Touch Wi-Fi Thermostat?

Choose the Sensi Touch if you want a colour touchscreen display; choose the standard Sensi Wi-Fi model if a basic backlit display suits you.

What does the claimed 23% energy saving mean for my actual heating and cooling bills?

The ENERGY STAR certification indicates the ST55 can reduce HVAC energy use by about 23% through flexible scheduling, remote access and usage reports.

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