Picture of an installed and operating RTH7600D Programmable Thermostat by Honeywell.

How to Calibrate a Honeywell Thermostat

In this post, we show how to calibrate a Honeywell thermostat.  Now why would you wish to do this?  Well, perhaps your Honeywell t-stat reads warmer or cooler than the room feels.  So you’d like to bring the t-stat temp reading more inline with how it really is.

Or, maybe you put your t-stat on an extra warm wall in your home.  If so, the rest of the house may feel too cold in winter, and too warm in summer.  Or vice versa.  That is, if you place the t-stat on a cool wall, then the reverse may happen.  The rest of the home might feel too cold in the summer, and too warm in winter.

Now the thermostat reading may simply be wrong. Or the reading is right. But the t-stat sits in an extra warm or cool place in the home. To solve these problems,  calibration of the t-stat will probably help.





Calibrating a Honeywell thermostat is a simple process really. So long as the t-stat you have has a temperature offset adjustment, setting it the right way is easy.  Honeywell does in fact, have this offset setting in its 9000 series RTH9580WF internet controlled t-stat along with several other models. This is the t-stat we use in our home. So, we’ll discuss next, how to set this offset for better comfort control from this t-stat.

Note that this post applies to the other series 9000 Honeywell t-stats as well.

How to Calibrate a Honeywell Thermostat

The calibration process has two main steps.  First, you figure out how far off the sensed t-stat temp is from real room temperature.  Then, you set the thermostat temperature offset parameter to account for that. Simple, right?  Right!

Find Honeywell Thermostat Offset

Picture of the Honeywell RTH9580WF thermostat on the same wall as a typical fridge freezer thermometer, used for temperature calibration.
Calibrating Honeywell RTH9580WF thermostat using a fridge freezer thermometer, with both on same wall.

1. Get an Accurate Thermometer

For this demo, we used a fridge-freezer thermometer as a reference, which works pretty well.  But for best results, buy a glass thermometer that reads temps in the temp range from 50 to 90 degrees.  Not only does this thermometer read more accurately, its scale is often larger.  So, it’s easier to see.

2. Place the Thermometer Near the Thermostat

Put it as close as you can.  We hung our thermometer on the same wall as the t-stat.  See the picture above.





3. Allow Temperature Readings to Stabilize

Let the thermometer hang for twenty minutes to a half hour.  This allows it to accurately read room temp.

4. Read the Thermostat and Thermometer Temperatures

In our case, the thermometer read the room at 76 degrees F. But the t-stat read it at 77 degrees F.

5. Calculate the Temperature Offset

Now assume that the thermometer reads the more right of the two.  Then, the room temp reads 1 degree less on the thermometer than what the thermostat reads.  We need this figure in the next task.





Calibrate the Honeywell Thermostat

Many Honeywell t-stats allow setting the -1 degree temp offset we found above with the thermometer.  Here, we show how to do it on our 9000 series RTH9580WF Wi-Fi thermostat.  You start at the   Home   screen, as shown next.

Picture of the Honeywell RTH9580WF WiFi thermostat, showing its -Home- screen, with the -Menu-button highlighted.
Honeywell RTH9580WF WiFi thermostat, showing its -Home- screen, with the -Menu-button highlighted.

1. Tap the  MENU  Button on the Honeywell Thermostat Home Screen

This brings up the main menu, as we see next.

We then scroll down using the arrow buttons, to bring the  Preferences  item into view.

Picture of the Honeywell RTH9580WF t-stat, showing its -Main Menu- screen, with the -Preferences- button highlighted.
Honeywell RTH9580WF t-stat, showing its -Main Menu- screen, with the -Preferences- button highlighted.

2. Tap the   Preferences   Button

Find this button pointed at by the pink arrow in the last picture.





The  Preferences  screen then shows, as we see next.  We then scroll down using the arrow buttons, to bring the  Advanced Preferences  item into view.

Picture of the Honeywell RTH9580WF t-stat, showing its -Preferences- screen, with the -Advanced Preferences- button highlighted.
Honeywell RTH9580WF t-stat, showing its -Preferences- screen, with the -Advanced Preferences- button highlighted.

3. Tap the  Advanced Preferences  Button to Continue with How to Calibrate a Honeywell Thermostat 

This shows the first in a series of advanced settings screens then; the  Scheduling Options screen, as shown next.

Picture of the Honeywell RTH9580WF thermostat, showing its -Advanced Preferences, Scheduling Options- screen.
Honeywell RTH9580WF thermostat, showing its -Advanced Preferences, Scheduling Options- screen.

4. Repeatedly Press the Green  Next   Button Until you Reach the  Indoor Display Offsets   Settings Screen

See this screen shown next.

Picture of the Honeywell RTH9580WF thermostat, showing its -Indoor Display Offsets- screen, with the -Indoor Temperature Offset- buttons highlighted.
Honeywell RTH9580WF thermostat, showing its -Indoor Display Offsets- screen, with the -Indoor Temperature Offset- buttons highlighted.

5. Adjust Indoor Temperature Offset

Use the UP and DOWN arrow buttons to set the indoor temp offset.  We circle these in pink, in the last picture.





Recall that we found  -1 degree F for our temp offset.  Thus we tap the DOWN arrow once to enter -1 degree, as we show next.

Picture of the Honeywell thermostat, showing its -Indoor Display Offsets- screen with a minus 1 degree temperature offset highlighted.
S Honeywell thermostat, showing its -Indoor Display Offsets- screen with a minus 1 degree temperature offset highlighted.

6. Press the Red   Done   Button to Continue with How to Calibrate a Honeywell Thermostat

Your t-stat then asks whether you wish to save your settings changes, as we see next.

Picture of the -Exit Advanced Preferences- screen, prompting for -Save Changes- confirmation.
The -Exit Advanced Preferences- screen, prompting for -Save Changes- confirmation.

7. Press the Green   Yes   Button

The   Saving Changes   screen then briefly shows, as seen next.

Picture of the -Saving Changes- screen.
The -Saving Changes- screen.

After the new temp offset setting saves, you see the next screen.

Picture of the -Preferences- screen, with the -Previous Menu- button highlighted.
The -Preferences- screen, with the -Previous Menu- button highlighted.

8. Tap the  Previous Menu   Button to Continue with How to Calibrate a Honeywell Thermostat

Then, doing so returns you to the  Main Menu  screen, as we see next.

Picture of a typical Honeywell thermostat, showing its -Main Menu- screen, with the -Home- button highlighted.
A typical Honeywell digital thermostat, showing its -Main Menu- screen, with the -Home- button highlighted.

9. Tap the   Home   Button

This completes then, the temp offset setting routine. The Home button returns you to the thermostat’s Home screen, as shown next.  Note that this screen appears as it did before we calibrated the offset.  E.g. The temp still reads 76, and so does the set temperature.  But our place now feels a little warmer (one degree warmer, in fact).  Now had we made a bigger change, such as -4 degrees, then the current t-stat temp would read lower.





But since we changed ours just -1 degree, the furnace had enough time to raise the room temperature.  This made up for that one degree.  So, the current reading stayed the same in this case.

Picture of the -Home- screen, after new temperature offset applied.
The -Home- screen, after new temperature offset applied.

10. Done with How to Calibrate a Honeywell Thermostat !

Finally, your HVAC system will now, for negative temp offsets, keep your place a little warmer.  Further, for positive temp offsets, your home will stay a bit cooler.

Other Posts About the Honeywell Thermostat

    1. Honeywell Thermostat Waiting for Equipment Message
    2. How to Change Time and Day on a Honeywell Thermostat
    3. How to Set Honeywell Thermostat Temperature Offset
    4. Honeywell Thermostat Reset WiFi Instructions
    5. How to Turn Off Hold on Honeywell Thermostat

References for How to Calibrate a Honeywell Thermostat

  1. User Guide for a Common Honeywell Thermostat   from Honeywell

Revision History

  • 2023-01-13: First published.
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