Honeywell RTH8500D 7-day Touchscreen Programmable Thermostat Review

Published in Programmable Thermostats on 9th May 2012

Image from Amazon

Another model in the Honeywell 7-day programmable thermostat series is the RTH8500D.

This Honeywell thermostat has all the beneficial functions that are present in the Honeywell RTH7600D with one additional function that is the “Vacation Hold” option.

For those who have already decided, here is the link from Amazon offering this product: Honeywell RTH8500D Best Deals.

If not I have provided a an unbiased review below of this Honeywell thermostat series below that is a good DIY green project to cut down on your utilities worth considering.

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.

There is also the “Vacation Hold” option in the RTH8500D for you to adjust your program and have it to resume the normal settings automatically in time for your return from your trip. To facilitate the ease in applying this function, there is also a shortcut provided in the programming interface that allows 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?


90 customers at Amazon gave the Honeywell RTH8500D an average of 4.5/5 stars. Out of 90 customers, 64 gave it 5.0/5 stars.

Home Depot

7 customers at Home Depot gave the Honeywell RTH8500D an average of 3.4/5 stars. Out of 7 customers, 4 gave it 5.0/5 stars.


57 customers at Nextag gave the Honeywell RTH8500D an average of 4.6/5 stars. Out of 57 customers, 44 gave it 5.0/5 stars.


1 customer at Lowes gave the Honeywell RTH8500D 5.0/5 stars.

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 “Vacation Hold” function for the Honeywell RTH8500D 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

Warranty Information

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

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

 (Download the Installation Manual for Honeywell RTH8500D here)


(Last Updated 14th December 2013)