---
product_id: 261521500
title: "Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified, ST55"
brand: "emerson"
price: "5639744₫"
currency: VND
in_stock: true
reviews_count: 1
category: "Emerson"
url: https://www.desertcart.vn/products/261521500-sensi-wi-fi-smart-thermostat-for-smart-home-diy-works
store_origin: VN
region: Vietnam
---

# Save 23% HVAC energy Remote access & app control DIY install, no c-wire needed Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified, ST55

**Brand:** emerson
**Price:** 5639744₫
**Availability:** ✅ In Stock

## Summary

> 🌡️ Upgrade your comfort, save energy, and stay smart—because your home deserves the best.

## Quick Answers

- **What is this?** Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified, ST55 by emerson
- **How much does it cost?** 5639744₫ with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/261521500-sensi-wi-fi-smart-thermostat-for-smart-home-diy-works)

## Best For

- emerson enthusiasts

## Why This Product

- Trusted emerson brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Effortless DIY Setup:** Install in minutes with built-in level and step-by-step app guidance—no electrician required.
- • **Energy-Smart Savings:** Cut your HVAC energy bills by up to 23% with ENERGY STAR-certified efficiency.
- • **Privacy-First Design:** Your data stays yours—Sensi never sells your personal info to third parties.
- • **Proactive HVAC Health:** Get real-time alerts and maintenance reminders to keep your system running at peak performance.
- • **Seamless Smart Home Sync:** Works flawlessly with Alexa and your favorite smart home devices for hands-free comfort control.

## Overview

The Emerson Sensi Wi-Fi Smart Thermostat (ST55) is an ENERGY STAR-certified, easy-to-install smart thermostat compatible with most HVAC systems without requiring a common wire. It offers flexible scheduling, remote app control, Alexa integration, and proactive maintenance alerts, all while prioritizing user privacy by not selling personal data.

## Description

DIY your smart home with the Sensi smart thermostat. Compatible with most residential HVAC systems — no common wire (c-wire) required in most applications. You can trust Sensi as we do not sell your personal information to third parties. And Sensi comes with the dependable performance and reliability you can count on from our 100 years of HVAC experience. With our top-rated mobile app and easy installation process, customers of all comfort levels can make the switch to a Sensi smart thermostat. For more information on Compatibility, Energy Savings, and Privacy Protection, please refer to the “Product Documentation” section below.

Review: Very good product - Nice

## Features

- PRIVACY PROTECTION*: Sensi won’t sell your personal information to third parties
- EASY DIY INSTALLATION: Use the built-in level and step-by-step app instructions for a quick installation. Works with HVAC equipment found in most homes. Common wire (c-wire) is not required in most applications
- SAVE ABOUT 23% ON HVAC ENERGY*: The ENERGY STAR-certified Sensi smart thermostat can help you save energy with features like flexible scheduling, remote access, and usage reports
- SMART MAINTENANCE: Sensi can help monitor the performance and efficiency of your HVAC system by delivering valuable usage reports, alerts about your equipment, and maintenance reminders like filter replacement
- SIMPLE CONFIGURATION: Looks and feels like a thermostat. Has buttons and fits the same space as a traditional thermostat so you don’t have to patch and paint your walls

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01NB1OB0I |
| ASIN  | B01NB1OB0I |
| Additional Features | Remote Access, Smart Home Integration, Flexible Scheduling |
| Backlight | Yes |
| Batteries  | 1 AAA batteries required. (included) |
| Best Sellers Rank | #57,455 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #204 in Home Thermostats & Accessories |
| Brand Name | Emerson |
| Color | White |
| Connectivity Protocol | Wi-Fi |
| Connectivity Technology | Wi-Fi |
| Control Method | App |
| Control Type | Button Control |
| Controller Type | Amazon Alexa |
| Customer Reviews | 4.4 4.4 out of 5 stars (2) |
| Customer reviews | 4.4 4.4 out of 5 stars (2) |
| Date First Available  | 11 June 2017 |
| Department  | Unisex-Adult |
| Display Type | digital |
| Finish Types | Glossy |
| Global Trade Identification Number | 00786710554827 |
| Included Components | Mounting bracket, level, app instructions |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions D x W x H | 2.5D x 14.9W x 9.5H centimeters |
| Item Type Name | , Works with Alexa, Energy Star Certified |
| Item Weight | 386 g |
| Item model number  | ST55 |
| Manufacturer | Emerson Thermostats |
| Manufacturer  | Emerson Thermostats |
| Material Type | Plastic |
| Model Name | Sensi |
| Model Number | ST55 |
| Mounting Type | Wall Mount |
| Number of Batteries | 1 AAA batteries required. (included) |
| Power Source | Corded Electric |
| Product Dimensions  | 9.53 x 14.94 x 2.54 cm; 385.55 g |
| Product Style | DIY |
| Screen Size | 5 Inches |
| Shape | Rectangular |
| Specific Uses For Product | Air Conditioner, Boiler, Furnace, Heat Pump |
| Specification Met | Energy Star |
| Temperature Control Type | Programmable, Smart/Remote |
| UPC | 786710554827 |
| Unit Count | 1 Count |
| Voltage | 24 Volts (AC) |

## Product Details

- **Brand:** Emerson
- **Controller type:** Amazon Alexa
- **Model name:** Sensi
- **Product dimensions:** 2.5D x 14.9W x 9.5H centimeters
- **Special features:** Remote Access, Smart Home Integration, Flexible Scheduling

## Images

![Sensi Wi-Fi Smart Thermostat for Smart Home, DIY, Works With Alexa, Energy Star Certified, ST55 - Image 1](https://m.media-amazon.com/images/I/61Rl-IZR--L.jpg)

## Available Options

This product comes in different **Pattern, Style** options.

## Questions & Answers

**Q: Can you create a fan schedule?  I’d like the fan to always run from 10pm until 6am.**
A: Updated Answer:
THANK YOU to Albert who pointed out below that the fan can be controlled through SmartThings! It was annoying to have to set up another app and service to do this, but it is a workaround to get around Sensi's frustrating limitation. SmartThings allows you to set the fan to Auto, On, or Circulate (but not the percentage of time to circulate) and automate that on any schedule you want. Unfortunately, Alexa and Google still don't allow you to control the fan at all, even though Sensi's API apparently allows it.

Original Answer from June 6, 2020:
No, you can't do a schedule like if you want it to run all the time during the night. Also, you can't control the fan from Alexa to schedule it that way. Very annoying and unreasonable that they wouldn't add that option since you can turn it on manually from the app. They do have the auto-circulate feature, but that's not the same.

**Q: Is it smart enough to decide whether to run the heater or cooler to keep the temperature fixed?**
A: In spite of the snarky answer above that says that's what a thermostat does, it should be noted that a thermostat doesn't just so that unless it is a feature of the thermostat.

A thermostat is for comparing existing ambient temperature to programmed temperature. On a furnace, if the temperature exceeds the programmed temp, the furnace simply will not run. THAT is what a thermostat does. UNLESS there is the ability to set said thermostat to automatically adjust the temp to the programmed temp.

**Q: Can you program just the fan mode?**
A: As pointed out on a similar question, the Sensi app does not allow scheduling of the fan mode, but you can do it with a 3rd party integration to the SmartThings app. Unfortunately, Alexa and Google don't have the option to control the fan either, but the SmartThings workaround was good enough for me to set our fan to run automatically at night and turn off in the morning.

**Q: What if i have a C wire?**
A: The "C-wire" is the second wire for 24VAC which is used to power advanced thermostats. Older thermostats were just a mercury switch and didn't have a need for additional power supply. Most newer systems are using 5-conductor thermostat wire.. Think of it as the plus side of a DC circuit/battery (but it is AC[thermostats have a rectifier to convert the AC to DC for their use]). Use it and the "common-wire" to supply 24VAC to the thermostat and zone valves/zone dampers. Without it, the thermostat runs on battery all the time and will quickly run down with WiFi.  Add a zone controller like a Honeywell HZ311 which has full modern voltages output; i.e., c-wire with 24VAC. This control requires a 24VAC transformer and daisy chains the 24VAC to thermostats and works on older systems since it provides its own c-wire output to advanced thermostats.

## Customer Reviews

### ⭐⭐⭐⭐ Very good product
*by N***K on 7 November 2024*

Nice

## Frequently Bought Together

- Sensi Smart Thermostat, 100 Years Of Expertise, Wi-Fi, Data Privacy, Programmable, Easy DIY Install, Works With Alexa, Energy Star Certified, Mobile App, ST55
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*Product available on Desertcart Vietnam*
*Store origin: VN*
*Last updated: 2026-04-24*