Picture of the Honeywell RTH9580WF thermostat, displaying the Connection Unsuccessful screen.

Fixing WiFi Problems on Honeywell Thermostat

The Honeywell RTH9580WF 1005 Smart WiFi Thermostat offers convenience and programming flexibility along with remote access and control via the  Honeywell Total Connect Comfort  website. But this thermostat relies on a solid WiFi internet connection to work, and often problems and issues arise with this link.  These can interfere with remote control of the t-stat. So here, we go over fixing WiFi problems on Honeywell RTH9580WF smart WiFi thermostat.





You can control most all of its features via its full color touchscreen locally, or from the TCC portal.

Picture of the Honeywell RTH9580WF WiFi Smart Thermostat, displaying the Home screen. Fixing WiFi Problems on Honeywell Thermostat.
Honeywell RTH9580WF WiFi Smart Thermostat, displaying the Home screen.

 

However, sometimes problems arise, particularly with the connection this thermostat must have to the internet, and the functions that require that connection.  Here, we explore some of the issues we’ve encountered, and they were solved.  Below, we list each problem under its own heading, and provide discussion of how to resolve it beneath.

Before delving into troubleshooting however, we recommend rebooting the thermostat.  This often clears up unexpected behaviors.

It is assumed here that you’ve properly installed and wired your thermostat, and that all local functions work correctly (setting temperature, programming the schedules, turning on the fan, heating, cooling, and so on).  Resolve any local issues between the thermostat and your HVAC or furnace system, before attempting to connect the RTH9580WF to the internet.

Fixing WiFi problems on Honeywell RTH9580WF Wireless Thermostat

Now, to the problems list.

Thermostat Not Connected to WiFi

If the thermostat is not connected to your WiFi network, you need to connect it for full function.  See our  Change WiFi Network on Honeywell Smart Thermostat RTH9580WF   piece for instructions on how to do that.

My WiFi Network Not Visible on Thermostat

No 2.4 Ghz. Network Found

Make sure you have a 2.4 Ghz Wi-fi b/g network SSID configured on your router / access point.  Keep in mind that the RTH9580WF thermostat does not see 5 Ghz. networks.  So, you will not be able to connect the thermostat to wireless N or AC networks.

Access Point is OFF

Check that your router / access point is running and working properly.  For non hidden networks, make sure you can see and connect to them on another Wi-Fi device.

Your Wireless Network is Hidden

Or, perhaps you hid your 2.4 Ghz. wireless network.  E.g. Your router does not broadcast its SSID.  Now some folks choose this stealth mode to keep hackers from seeing their network via network scans.  Check for this in your router settings. Then, if you did hide your Wi-Fi network, it will not show up on the t-stat.  If you hide your network on purpose, then choose the Other option on the thermostat’s Select Wi-Fi Network screen.  There, you manually enter your network name (SSID), along with its security type and password.  More on network security types below.

Picture of the Honeywell RTH9580WF thermostat, displaying the Select WiFi Network screen, with the Other... option highlighted.
Honeywell RTH9580WF thermostat, displaying the Select WiFi Network screen, with the Other… option highlighted.

Fixing WiFi Problems on Honeywell Thermostat: The Thermostat Does Not Connect to My Wireless Network

When this error occurs, variations on the following Connection Unsuccessful message display on the RTH9580WF touchscreen.

Picture of the Honeywell RTH9580WF thermostat, displaying the -Connection Unsuccessful- screen. Fixing WiFi Problems on Honeywell Thermostat.
Honeywell RTH9580WF thermostat, displaying the -Connection Unsuccessful- screen.

This failure has numerous causes, as described below.

Make Sure your Wi-Fi Network is Working Correctly

See if you can connect to your wireless network with another device, such as a tablet computer or phone.  If you are unable to connect with that other device, you’ll have to troubleshoot elsewhere, outside of the thermostat itself.  Verify proper operation of your router / access point.  Often, reboots of these components will fix this sort of issue.  If not, then read on.





You’re Using the Wrong WiFi Network Name (SSID)

If you see your Wi-Fi network on the thermostat, but it will not connect, verify that you’re choosing the correct SSID from the available wireless networks list.  Larger homes and businesses with multiple networks (access points) broadcasting, with similar names, are particularly vulnerable to this error.

You’re Entering the Wrong WiFi Password

Verify that you’re typing in the correct password; the virtual keys on the RTH9580WF touchscreen keyboard are quite small, and very easy to “fat finger” and press the wrong ones. These passwords are case sensitive.  So be sure to capitalize the letters correctly, and avoid mistaking letters for numbers or symbols, such as an l for a 1, a B for an 8, or an I for a !.

The RTH9580WF indicates an incorrectly entered password as shown in the next picture.  Any other failure message indicates that it’s NOT the password that’s at issue.

Picture of the Honeywell RTH9580WF Smart Thermostat, displaying the Connection Unsuccessful screen, due to an incorrect network password.
Honeywell RTH9580WF Smart Thermostat, displaying the Connection Unsuccessful screen, due to an incorrect network password.

Weak Wi-Fi Signal

Check Wi-Fi signal strength at the thermostat.  We prefer seeing very strong (all bars) wireless signals as shown in the next picture, for the most reliable wireless operation.  So, try to get the strongest signal possible from your desired network, at the thermostat.  Move your router closer to the RTH9580WF to get it, use a higher power access point, or purchase an access point with removable antennae, and buy longer aerials with higher DB gain.

Picture of the Honeywell RTH9580WF thermostat, displaying the Select Wi-Fi Network screen, showing the wireless signal strength meter with a full strength signal.
Honeywell RTH9580WF thermostat, displaying the Select Wi-Fi Network screen, showing the wireless signal strength meter with a full strength signal.

Interference from Other Devices and Networks

Bluetooth devices, microwave ovens, baby monitors, and certain cordless telephones may interfere with the Wi-Fi signal reaching your thermostat, causing erratic operation even though the signal strength may read Full.  Move such devices away from the RTH9580WF and the access point.

Congested Wi-Fi Network Channel

Your access point may use a busy channel.  So try changing that channel.  The best ones to use are channels 1, 6, and 11.  Try one of these three first, and only resort to the others if none of these work.  If you have an Android tablet or phone, you can download the Amped Wireless Wi-Fi Analytics app. Use the Channel Graph section in that app to tell if your channel is clear of noise.





Wrong Security Type Chosen for Hidden Wireless Networks

The problem with using obscured wireless networks is that connecting to them is error prone.  Not only must you know the SSID of the desired network (since it does not display in the network scan results), but you must also provide the network security parameters (either WEP, WPA with TKIP, WPA with AES, WPA2 with TKIP, or WPA2 with AES security.  If you enter these in error, your thermostat will fail to connect due to a timeout error as displayed above.  The RTH9580WF will not tell specifically that you chose the wrong authentication or encryption modes for the entered network name; it just issues the generic “connection has timed out” message, as shown above.

Picture of the Honeywell RTH9580WF thermosat, displaying the Select Network Security screen. Fixing WiFi Problems on Honeywell Thermostat.
Honeywell RTH9580WF thermostat, displaying the Select Network Security screen.

We recommend, for maximum security, configuring your Wi-Fi access point for WPA2 with AES for the hidden network, and then choose the same setting on the RTH9580WF Select Network Security screen pictured in the previous screen shot.

Fixing WiFi Problems on Honeywell Thermostat: The Thermostat Connects But Has No Internet Access

There’s an Internet Outage in Progress

This may occur if your router has lost its internet feed, such as when there’s an outage in your internet service provider’s network or equipment.  This may show up as a “waiting for update” message. This message displays on the RTH9580WF home screen, where the outdoor temperature normally appears.

Faulty Network Cable

Check all cables and wires in your local network; especially the Ethernet cable that connect the (DSL or cable) modem to your access point, if separate from the modem.  Broken connector tabs can cause cables to unplug and result in no internet access.  Also, again, check your net connectivity with another device.  If that works, but thermostat does not, then you may have a defective thermostat.  Try a different one to rule out the thermostat itself as the problem.

Thermostat Has Internet but Does Not Show Up in Total Connect Comfort Website

Thermostat Not Registered

To access the RTH9580WF on the Total Connect Comfort website, you must register the t-stat there.  To do that, visit that site here.  You’ll need to create an account if you don’t have one already. Plus, you will also need your thermostat’s CRC number.  Get that from its  Wi-Fi setup screen once you’ve successfully connected it to the internet.

Other Posts About the Honeywell RTH9580WF Thermostat

  1. Honeywell RTH9580WF WiFi Setup Instructions
  2. Change WiFi Network on Honeywell Smart Thermostat RTH9580WF
  3. How to Change Honeywell Thermostat Temperature Setting
  4. Change Time and Day on Honeywell RTH9580WF Thermostat, How To
  5. Connecting Amazon Echo Dot to Honeywell Thermostats




References for Fixing WiFi Problems on Honeywell Thermostat

  1. Honeywell Total Connect Comfort Website
  2. RTH9580WF User Guide

Revision History

  • 2020-04-19: Added more tags.
  • 2019-01-02: Added subheadings.
  • 2017-02-23: Updated the tags list.
  • 2016-12-14: Originally published.
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