Green Energy Helps
Written by Wilson Yeo on May 9, 2012 
Last updated: 26/04/2024

Honeywell RTH8500D 7-day Touchscreen Programmable Thermostat Review

Last updated on April 26th, 2024 at 01:09 pm

Image from Amazon

Another model in the Honeywell 7-day programmable thermostat series is the RTH8500D.The Honeywell RTH8500D has similar functions as the Honeywell RTH7600D, with one additional “Vacation Hold” option.

For interested readers, here is my unbiased review of this Honeywell thermostat.

Benefits of Owning A Honeywell RTH8500D

Clear Backlit Touchscreen Display

The Honeywell RTH8500D has a large backlit display with a touchscreen interface that allows for easy programming. Its green backlight also allows you to read your programmed settings under low lighting conditions.

7-Day Programming

The Honeywell RTH8500D allows the customisation of your household’s heating and cooling schedule differently for 7 days (1 week). Within this heating and cooling schedule, you can further customise your settings differently for 4 periods within a 24 hour time frame.

Honeywell Smart Response Technology

This technology present in this Honeywell thermostat series allows the continual and automatic adjustment of the pre-heating/cooling temperature of your home to give you precise comfort control within one-degree Fahrenheit of your programmed temperature.

Power Source

The Honeywell RTH8500D is powered by 3”AAA” batteries. For added convenience, this thermostat unit can also be run using power from your heating/cooling system, giving you the option of permanently eliminating battery changes.

Compatible with Most Systems

The Honeywell RTH8500D is compatible with a wide range of heating and cooling systems that include:

  • Heating and Cooling Systems that include both Single-Stage and Multi-Stage
  • Heating/ Cooling only
  • Furnace (Warm Air)
  • Central Air Conditioning
  • Heat Pump with or without Auxiliary Heat
  • Hot Water
  • Steam or Gravity
  • 750 Millivolt
  • Gas Fireplaces

But it is not compatible with electric baseboard heat (120 to 240 volts).

Green Product

This Honeywell thermostat allows you to save up to 33 percent on annual heating and cooling costs though it may depend on geographic region and energy usage.

Additional Features

The permanent day and time settings that you have programmed on the Honeywell RTH8500D are maintained even during power outages. There is also an option of automatic adjustment for Daylight Savings Time as well as a filter-change and low battery reminder function that ensure your heating-cooling system is operating at its best.

The “Vacation Hold” option allows you to program your heating/cooling schedule for automatic resumption to normal settings to coincide with your return day. To facilitate this, a shortcut is provided in the software interface for multiple days to be set up at once to fit your heating/cooling schedule.

Dimensions Height = 4.06 in.
Width = 6.25 in.
Depth = 1.25 in.
Weight = 0.80 pounds
Display Style Extra Large Hybrid Touch Screen Display
Additional Features -Battery Free Memory for All Programs and Settings
-5/2 minute selectable minimum Run/Off Time provide short cycle and compressor protection
-Keyboard Lockout
-12/24 Hr Display
-Temperature Calibration

Programming7 Day Programming with 4 periods per day
Energy Star Certified Heating/Cooling ProgramYes
Power Source2 "AA" Size Batteries

How does the Honeywell RTH8500D rank on popular websites?


1697 customers at Amazon gave it an average rating of 4.4/5.0. Out of 1697 customers, 1168 gave it the maximum rating of 5.0/5.0.

Home Depot

431 customers at Home Depot gave it an average rating of 4.3/5.0. Out of 431 customers, 283 gave it the maximum rating 5.0/5.0.


18 customers at Lowe's gave it an average rating of 4.7/5.0. Out of 18 customers, 15 gave it the maximum rating of 5.0/5.0.


2 customers at Walmart gave it an average rating of 4.5/5.0. Out of 2 customers, 1 gave it the maximum rating of 5.0/5.0.

Customer Reviews on Honeywell RTH8500D

I have read many recent customer reviews and have summarised the pros and cons of this Honeywell thermostat below.

The Pros

Ease of installation, usage and programming, and well designed appearance are some of the mentioned pros for the Honeywell RTH8500D. The programming shortcut provided that allows multiple days to be programmed at once has also been mentioned to be one of the positives.

Customers that go on long trips overseas frequently have also mentioned that the “Vacation Hold” function is a positive for them since this allows them to come back to a properly cooled house without the need to wait for the thermostat to start up.

The Cons

Some of the mentioned cons include the fact that there is no dedicated backlight button; the background is dark until you touch the surface, and the short time span of barely five seconds it stays on.

There have also been some complaints about the audible “click” sound of the relay contact when the RTH8500D activates the HVAC systems. This has also been mentioned for the RTH7600D and possibly for the rest of the Honeywell thermostats. This might be an issue if this thermostat is going to be installed in the bedroom and if one has sensitive hearing. So if you are going to install this unit or such thermostat, you might want to check to see if the noise level is bearable for you.

Other possibly isolated complaints include faulty accessories like cases of the installing pins that connect the thermostat to the wall plate breaking rather frequently

Product information and manual


This Honeywell thermostat is backed by a one-year warranty that covers any defects in workmanship or materials from the date of purchase.


Installation manual(PDF)

Best Deals for Honeywell RTH8500D

I have also discovered that the best place to get the Honeywell RTH8500D is online with many sites offering this thermostat at competitive prices. However among these sites, I have discovered that Amazon actually offers this Honeywell thermostat at a lower price.

So if this thermostat is suitable for you, here is the link from Amazon offering this product: Honeywell RTH8500D Best Deals


  • Wilson Yeo

    I am the admin of Green Energy Helps and I possess a keen interest in how green energy and leading a green lifestyle can help to reduce our individual carbon footprints. I will be providing information about green energy and lifestyle tips with unbiased reviews on green products for your consideration. Note: This website uses affiliate links which may earn a commission for purchases made at no additional cost to you.

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