---
product_id: 1173139
title: "Honeywell Home RTH221B1021/E1 Programmable Thermostat, Off White"
brand: "honeywell home"
price: "S$7"
currency: SGD
in_stock: false
reviews_count: 8
url: https://www.desertcart.sg/products/1173139-honeywell-home-rth221b1021-e1-programmable-thermostat-off-white
store_origin: SG
region: Singapore
---

# 4 programmable time slots/day 1-week single program ±1°F temperature accuracy Honeywell Home RTH221B1021/E1 Programmable Thermostat, Off White

**Brand:** honeywell home
**Price:** S$7
**Availability:** ❌ Out of Stock

## Summary

> 🌡️ Stay ahead of comfort—program your week, own your space!

## Quick Answers

- **What is this?** Honeywell Home RTH221B1021/E1 Programmable Thermostat, Off White by honeywell home
- **How much does it cost?** S$7 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.sg](https://www.desertcart.sg/products/1173139-honeywell-home-rth221b1021-e1-programmable-thermostat-off-white)

## Best For

- honeywell home enthusiasts

## Why This Product

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

## Key Features

- • **Energy-Smart Design:** Wall-mounted, low-power thermostat powered by 2 AAA batteries with an impressive 8760-hour battery life.
- • **Flexible Scheduling:** Customize up to 4 time periods per day across the entire week—perfect for your dynamic lifestyle.
- • **Precision Comfort Control:** Maintain your ideal temperature with ±1°F accuracy for consistent, cozy vibes all day.
- • **Clear & Customizable Display:** Switch between Fahrenheit/Celsius and 12/24-hour clock on a crisp digital screen with backlight.
- • **Universal HVAC Compatibility:** Seamlessly works with heating, cooling, and heat pumps (sans auxiliary heat) for effortless integration.

## Overview

The Honeywell Home RTH221B1021 is a programmable thermostat offering precise temperature control within ±1°F, featuring a single weekly program with 4 customizable time periods per day. Compatible with most heating and cooling systems (excluding electric baseboard heat), it boasts a clear digital display with Fahrenheit/Celsius and 12/24-hour options, powered by long-lasting AAA batteries for energy-efficient, hassle-free home climate management.

## Description

A simple, easy to use the 1-week programmable thermostat. You set it up to adjust the temperature when you are away or asleep-times when you don't necessarily need to heat or cool your home to optimum comfort-and your HVAC equipment runs less. Plus, your heating or cooling comes back to the comfort level you desire before you come home or wake up. Honeywell Home programmable thermostats are easy to install and are pre-programmed for your convenience. For more than a century, Honeywell Home thermostats have been the popular choice of homeowners. This thermostat is compatible with single-stage heating/cooling systems, heating, cooling, heat pumps without backup heat, mill volt, pellet stoves and fireplaces. It does NOT work with electric baseboard heat (120-240 V), heat pump systems with backup heat or multi-stage heating/cooling.

Review: ヽ(◉◡◔)ﾉ - Here the deal: We had one of those Commercial grade Honeywell touchscreen thermostats that usually do a great job, but we noticed the temperature in the house never seemed to keep, and would hear the unit, whether heater or ac, kick on quite a bit. We decided to do some research, and with a deal from our energy provider, we ended up with one of those $249 Nest thermostats. I was STOKED, like a fat kid with some apple pie. We got the Nest in, and I went to work. Like a Dad in bad joke bookstore. I've replaced many thermostats over the years and the Nest was a piece of cake. BUT, we discovered it had a malfunction, so after talking with tech support, it was getting replaced. SOOOO, back to the Honeywell. I went out to the garage and grabbed the oldie off the shelf, and as I was walking in, my Dollar Store flip flop got caught on the door jam. It popped the rubber thing out of the foam bottom and made me nearly fall over forwards onto the hard tiled floor. There i was, Rambo faced, screaming in slo motion, feeling the pain of my big toe hit the metal, when all of a sudden the Honeywell touch screen goes flying out of my hands, and flips, and turns, and swings, and screams, to the floor. BAM!!! Cracked screen. Out of Commission. No Goodie No More. Mad me. I dropped the ball, but it wasn't the ball man, it was my $150 Honeywell touch screen I had plans to put back onto the wall when we sold the house years from now. So there I was, at a cross roads, like Willow, but without Mad Mardigan there to take the baby. I broke my working thermostat, and was left with TWO broken thermostats. It was humid, then cold, then hot, then cold, then humid, the windows were open, they were closed, they were damned like Conan the Barbarian was. I decided to order THIS thermostat from desertcart. I got in two days, and the hookup was easy. Easy yo. I'm talking so easy, I thought about taking it for a drink and a meal. The thermostat works like a champ! However I now rec'd the replacement Nest thrmostat and this one is taken down, boxed up, and awaits its new homeowner in severla years whoever and whenever that may be. Pros: 1. Easy to install (C wire is Common and NOT used) 2. Basic use makes ti fun for all ages! 3. Basic programming is available, but nothing that is 3 pointer at the buzzer wow 4. Small, and easy to use Cons: 1. None. It works great and is easy to install
Review: Very easy to install and works well - I wanted a simple to install thermostat to replace the aging, mercury switched Honeywell items that control our heat and cooling. After researching I decided that a simple weekly timer is good enough, and certainly better that what we had originally. The RTH221B shows the current temperature and can be set to adjust the temperature when you wake, leave, return and night. It is simple to use with 15 minute increments. Installation says "15 minutes or under" and I found this to be true. To install: Turn off power to furnace and thermostat (although it is a low voltage feed, you MUST still do this) Unscrew the original thermostat from the wall but leave wires attached Check the color of the wires and which terminals they attach to on the original (look for small letters W,R,Y,Rc etc) Mark the wires (if needed) with the stickers provided in the package Unhook wires from the original Remove backing plate from new thermostat, thread wires through hole and place against wall Attach backing plate using screws and wall plugs provided Put 2 x AAA batteries(NOT supplied)in the faceplate Attach previously marked wired to the matching terminals at the back of the faceplate Snap faceplate onto backing plate Read instructions for setting time and programs Turn power to furnace back on Pros: cheap, easy to install, good instructions Cons: would have been nice to include 2 x AAA batteries Overall a good buy. I fitted one as a test and then bought 3 more.

## Features

- One program for the entire week-4 periods per day. This product is easy to use
- Digital displays. This product is highly durable and easy to handle
- Compatible with heating, cooling and heat pumps without auxiliary heat. Does not work with electric baseboard heat (120-240V) multistage HVAC systems
- Accurate temperature control of +/-1-Degree F for consistent comfort. Do not use Cooling mode when the outdoor temperature is below 50 °F (10 °C)
- Display options: Fahrenheit or Celsius temperature display, 12 or 24 hour clock
- This product is manufactured in China. Not compatible with electric baseboard heat and multistage HVAC systems

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0088A5X5G |
| Average Battery Life | 8760 Hours |
| Backlight | Yes |
| Batteries | 2 AAA batteries required. |
| Batteries Included? | No |
| Batteries Required? | Yes |
| Best Sellers Rank | #454,831 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #552 in Home Programmable Thermostats |
| Brand | Honeywell Home |
| Color | Off White |
| Connectivity Protocol | Wi-Fi |
| Connectivity Technology | Wi-Fi |
| Control Method | Touch |
| Control Type | Button Control |
| Controller Type | Push Button |
| Customer Reviews | 4.3 4.3 out of 5 stars (4,240) |
| Date First Available | March 15, 2010 |
| Display Type | Digital |
| Global Trade Identification Number | 00085267866958 |
| Included Components | Thermostat, Mounting Hardware, User Manual |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 7.2 ounces |
| Item model number | RTH221B1021/E1 |
| Manufacturer | Honeywell Home |
| Material | Plastic |
| Model Name | RTH221B1021 |
| Mounting Type | Wall Mount |
| Number of Batteries | 2 AAA batteries required. |
| Part Number | Home |
| Pattern | Thermostat |
| Power Source | Corded Electric |
| Product Dimensions | 3.75 x 1 x 4.75 inches |
| Screen Size | 8 Inches |
| Size | EA |
| Special Feature | Programmable, Temperature Display |
| Special Features | Programmable, Temperature Display |
| Specific Uses For Product | Furnace |
| Specification Met | Energy Saving Thermostat |
| Style | Original_Style |
| Temperature Control Type | Heating |
| UPC | 085267866958 |
| Voltage | 120240 Volts |
| Warranty Description | Comes with manufacturer warranty. |

## Product Details

- **Brand:** Honeywell Home
- **Color:** Off White
- **Controller Type:** Push Button
- **Model Name:** RTH221B1021
- **Special Feature:** Programmable, Temperature Display

## Images

![Honeywell Home RTH221B1021/E1 Programmable Thermostat, Off White - Image 1](https://m.media-amazon.com/images/I/51suD3FrYKL.jpg)

## Available Options

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

## Questions & Answers

**Q: Will it work on 12v RV replacements?**
A: yes sir, it will work in replace of many thermostats. amazingly inexpensive for all the features. ive used on everything from camp heaters in an rv to full central heat ac systems.hope this answered your question.

**Q: Does the display light up?**
A: No, the display does not light up.  It is a very basic, but very simple to operate unit.

**Q: What is the lowest temperature setting.  I just need a setting to keep pipe from freezing, 35 or 40 degrees maybe?**
A: It goes down to 40, but be careful.  40 degrees at the interior location of the thermostat does not guarantee that the basement and pipes in exterior walls will stay above freezing.  If you have fixtures on exterior walls, typically kitchen sink, leave the sink base cabinet door open to allow the pipes to be exposed to warmer room air

**Q: I'm replacing my analog thermostat with a digital one. The ones at Lowes and Home Depot are almost $100 or more, will this work just as well?**
A: Yes, this should work just fine.  Pricier model are just prettier and have more sophisticated programming and/or connecting to your smart phone abilities.  As far as programming goes, this one is NOT a 1-week thermostat.  You can only create one daily program.  You set 4 points in a 24 hours span (i.e. 1-day) and then this program is repeated day after day.  If you don't need programming, there is a cheaper version where you just set the temperature.  Or there are pricier ones where you can create separate programs for work days and weekends ( 5/2 programming ) or 7 distinct programs for each day of the week (7-day thermostat).

## Customer Reviews

### ⭐⭐⭐⭐⭐ ヽ(◉◡◔)ﾉ
*by S***I on December 22, 2014*

Here the deal: We had one of those Commercial grade Honeywell touchscreen thermostats that usually do a great job, but we noticed the temperature in the house never seemed to keep, and would hear the unit, whether heater or ac, kick on quite a bit. We decided to do some research, and with a deal from our energy provider, we ended up with one of those $249 Nest thermostats. I was STOKED, like a fat kid with some apple pie. We got the Nest in, and I went to work. Like a Dad in bad joke bookstore. I've replaced many thermostats over the years and the Nest was a piece of cake. BUT, we discovered it had a malfunction, so after talking with tech support, it was getting replaced. SOOOO, back to the Honeywell. I went out to the garage and grabbed the oldie off the shelf, and as I was walking in, my Dollar Store flip flop got caught on the door jam. It popped the rubber thing out of the foam bottom and made me nearly fall over forwards onto the hard tiled floor. There i was, Rambo faced, screaming in slo motion, feeling the pain of my big toe hit the metal, when all of a sudden the Honeywell touch screen goes flying out of my hands, and flips, and turns, and swings, and screams, to the floor. BAM!!! Cracked screen. Out of Commission. No Goodie No More. Mad me. I dropped the ball, but it wasn't the ball man, it was my $150 Honeywell touch screen I had plans to put back onto the wall when we sold the house years from now. So there I was, at a cross roads, like Willow, but without Mad Mardigan there to take the baby. I broke my working thermostat, and was left with TWO broken thermostats. It was humid, then cold, then hot, then cold, then humid, the windows were open, they were closed, they were damned like Conan the Barbarian was. I decided to order THIS thermostat from Amazon. I got in two days, and the hookup was easy. Easy yo. I'm talking so easy, I thought about taking it for a drink and a meal. The thermostat works like a champ! However I now rec'd the replacement Nest thrmostat and this one is taken down, boxed up, and awaits its new homeowner in severla years whoever and whenever that may be. Pros: 1. Easy to install (C wire is Common and NOT used) 2. Basic use makes ti fun for all ages! 3. Basic programming is available, but nothing that is 3 pointer at the buzzer wow 4. Small, and easy to use Cons: 1. None. It works great and is easy to install

### ⭐⭐⭐⭐⭐ Very easy to install and works well
*by U***R on March 17, 2013*

I wanted a simple to install thermostat to replace the aging, mercury switched Honeywell items that control our heat and cooling. After researching I decided that a simple weekly timer is good enough, and certainly better that what we had originally. The RTH221B shows the current temperature and can be set to adjust the temperature when you wake, leave, return and night. It is simple to use with 15 minute increments. Installation says "15 minutes or under" and I found this to be true. To install: Turn off power to furnace and thermostat (although it is a low voltage feed, you MUST still do this) Unscrew the original thermostat from the wall but leave wires attached Check the color of the wires and which terminals they attach to on the original (look for small letters W,R,Y,Rc etc) Mark the wires (if needed) with the stickers provided in the package Unhook wires from the original Remove backing plate from new thermostat, thread wires through hole and place against wall Attach backing plate using screws and wall plugs provided Put 2 x AAA batteries(NOT supplied)in the faceplate Attach previously marked wired to the matching terminals at the back of the faceplate Snap faceplate onto backing plate Read instructions for setting time and programs Turn power to furnace back on Pros: cheap, easy to install, good instructions Cons: would have been nice to include 2 x AAA batteries Overall a good buy. I fitted one as a test and then bought 3 more.

### ⭐⭐⭐⭐ Good Value, Poor Documentation
*by G***S on January 19, 2017*

I replaced an old Honeywell mechanical thermostat with this Honeywell RTH221B1021/A 1 Week Programmable Thermostat. (I mention the exact model here because these reviews appear to include reviews for various other models, a practice I feel defeats the purpose of a review). The thermostat seems to be well enough constructed and functions as advertised, that is, is programmable for a single day in four selectable time periods and that day is replicated identically for each day of the 7 day week, or each day of the 365 day year, if you like. I agree with some who take exception to the description "1 week programmable". It should read "daily programmable", but for a retired person like me, it's perfect. The controls are very intuitive and ingenious in their simplicity. Set it and forget it, unless you want to alter the temperature for an indefinite time period, then just adjust the temperature on the display to the desired target temperature and press the "hold" button. To revert to the original program, simply press the "run" button. This review would have earned five stars had the thermostat come with any wiring instructions whatsoever. The adequate operating manual talks about programming only. I believe the only other instructions said to hook it up according to the color codes used for your previous thermostat, which is ludicrous. Mine is a two wire heat only system and there was nothing I could do but surf the internet for wiring color code conventions and verify I had the right connection terminals with an Ohm meter. Not a big inconvenience given the low price, but still, shame on you Honeywell!

## Frequently Bought Together

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*Product available on Desertcart Singapore*
*Store origin: SG*
*Last updated: 2026-03-16*