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Model # RTH221B

Internet # 203539508

Store SKU # 805478

7-Day Programmable Thermostat

This item has been discontinued.
The Home Depot no longer carries this specific product.

$19.88 /each




Model # RTH221B

Internet # 203539508

Store SKU # 805478

The Honeywell 1-Week Programmable Thermostat has a simple interface and offers one basic program for the entire week with 4 program periods. It automatically adjusts the heating or cooling of your home so you are comfortable when you wake up, come home or at any other time you prefer. Used as directed, it offers energy savings of up to 33%.

  • 1 basic program for the entire week
  • Easy to use, basic operation makes programming easy
  • Precise +/- 1°F temperature control
  • Easy to install
  • Home Depot Protection Plan:

    Home Depot Protection Plan

Info & Guides

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Display height (in.) 
1 in 
Display width (in.) 
1.75 in 
Product Depth (in.) 
Product Height (ft.) 
Product Height (in.) 
Product Width (in.) 
Batteries Included 
Battery Power Type 
Battery Size 
Color Family 
Number of HVAC Zones 
Periods per Programmable Day 
System Compatible 
24-Volt Heating & Aiir Conditioning System 
Thermostat Features 
Battery Operated,Low Battery Indicator 
Thermostat Type 
Heating and Cooling 
Voltage (volts) 
Warranty / Certifications
Certifications and Listings 
No Certifications or Listings 
ENERGY STAR Certified 
Manufacturer Warranty 
1 year limited warranty 


Rated 3.7 out of 5 by 88 reviewers.
Rated 1.0 out of 5.0 by would not recommend I bought this thermostat to replace a Z-wave thermostat. I opened the package and started to try, later had to pry open the thermostat to get to the connections and battery compartment. The difficulty in trying to open the thermostat was uncalled for in my book. I am no stranger to home repairs as I had my own business in doing a multitude of repairs. If I were to mount this thing to the wall and then had to replace the batteries I would have to tear it of the wall to do so. I think that Honeywell should try there products before packaging them. September 4, 2015
Rated 4.0 out of 5.0 by Works on Millivolt system Used on millivolt system. Works great. Don't know how long the batteries will last but initially it's easy to install and set up. Though the specs said it would work on a millivolt system, there was not any instructions on how to connect. Called Honeywell and after first saying it would not work on this system, when pressed they came up with instructions for this type connection. Simple connect the two leads to "R" & "W". Disconnect "RC" jumper. July 28, 2015
Rated 5.0 out of 5.0 by thermostat the thermostat was Easy to install and easy to program plus very inexpensive December 10, 2014
Rated 5.0 out of 5.0 by Easy to install Easy to insrall. Has helped lower electric bill while eliminating the need to adjust temperature each morning and evening September 8, 2015
Rated 5.0 out of 5.0 by Worked as discribed. The installation directions were clear, about where to insert wires that went to the original thermostat. It can be used manually or programed for the week. Just pay attention to the type AC install that you have and you shouldn't have any problem. We had a gas furnace with heat pump system installed. You do need to manually switch from AC to heat, and vice-versa. August 18, 2015
Rated 1.0 out of 5.0 by Janman The unit was DOA out of the box. This was the second one in as many years. I used them for apartments as they are low cost, but ended up to be just cheap junk! August 25, 2015
Rated 1.0 out of 5.0 by Product did not work Product did not work. Ended up calling in professional hvac help & they verified that it did not work. Returned for refund. August 25, 2015
Rated 3.0 out of 5.0 by Need to learn its ideosyncracies before you save on energy costs This is my second review. First was in the summer. Now it is the heating season. After getting my first gas bill (which was a bit higher than with my old thermostat) I noticed that this thermostat treats the set temp as the minimum temp. So if you set it to 65 the furnace turns on at 65 and shuts off a couple degrees higher. Other than that and the fact that you have to re-program it each time you switch between summer and winter settings it is a decent cheap thermostat. January 2, 2015
  • 2015-10-04T11:41:22.108-05:00
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