Can't reconnect Honeywell Lyric T5 thermostats through Honeywell Home

My Honeywell Lyric T5’s WiFi thermostats worked well connected to ST for years but lately they have not responded (ST showed changes but those changes didn’t get pushed to T5’s).

The T5’s work perfectly in the Resideo App

I went down a rabbit hole trying to fix them.

I removed the devices from ST … then removed them from Resideo.

Reinstalled them in Resideo

Choose Honeywell Home to connect the T5’s to ST … but they won’t show up. It indicates that “this partner service is connected because your account has been linked”

I click view linked service, and I get an error message “Couldn’t Add Device … A network or server error occurred”.

I looked on ST support for how to unlink services … thinking I need to refresh this connection. However I do not see “Linked Services” as stated when I select the “gear” icon.

Here are the instructions from ST website …

To remove a Linked Service from the SmartThings app, follow these steps:

  1. From the Favorites tab, select the Menu (☰)
  2. Tap the Gear (:gear:) and choose Linked Services
  3. Choose More Options (⋮) and select Delete
  4. Tap Minus (-) next to the Service
  5. Select Delete to confirm

I think if I can disconnect the HH service and
Reconnect, it might work.

Any help would be appreciated.


PS: Can’t find the option on things advanced web interface either.

Android or iOS?

Change the default browser on your mobile device and then try to add.

Safari was default. Changed to Chrome and no diff.

opened a case with ST support. Hopefully they will be able to delete the flawed connection to Honeywell Home and I’ll be back in business.

Getting back to you. Yes, ST does not expose the linked services through the Advanced Web App. Only the connected devices would appear in the Devices section.

That is very strange and ST Support should be alerted to this issue.

You may want to also contact HoneyWell support to see if they have identified any issues with the integration. They maintain the integration and they can help identify if the issue is with ST or their end. Don’t be surprised if both sides blame the other. :wink:

It could lead to both sides working together to identify and fix.

Same exact problem starting ~3 days ago with T6s. Completely removed all devices from the Residio app and then deleted my account and rebuilt. Resulting is similar error.

Yea … thanks.

I’m on my 2nd round with ST support. After I told them that I deleted/added devices on the Resideo side and sent them screenshots showing them that ST reports a connection with HH but the ST-app does not provide me a “linked services” option …

They told me to delete/add the devices on Resideo and use the “linked services” option in the ST-app to delete and remake the HH connection.


Par for the course I guess these days.

Let’s see what happens now that it’s been “escalated” (hopefully to someone who will read what I wrote this time)

Feel free to use my name and try to piggyback on my case if u want.

I might be going from the fat to the fire as we may be updating our heat pumps later this summer to Trane i17’s and apparently they need to use a Trane stat (says the installer).


Woke up to a surprise today and the integration is back to normal. I can see the linked service in the iOS application again. It does look like Resideo had maintenance on June 27th, which was about the time this nonsense started.

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ST support got it back so that “linked services” showed up again in the ST-app … and I was able to redo the link to HH.

However … a note about ST support.

Last night they elevated the case and said they would get back to me (this is all via txt).

This morning at 6:54am eastern USA … they text me a note saying they are going to close the case unless there was still an issue.

1 HOUR LATER … at 7:54am … they closed the case.

No explanation that they did anything … found anything … and only 1 hr to reply early in the morning. That’s REALLY BAD communication IMO.

Not sure if it helps any but my D6 pro or D9 pro recently went off line (past week) and I added the integration a few times with zero of my lyric devices showing each time. Last time i just logged in and forgot about it and 4 days later the devices finally show up on my SmartThings app

Also, you might try adding it as a different type of thermostat. I’ve had to do that also with my Lyric D6 pro.

Seems to be working now … once ST did something to allow the link to HH to show up in ST-app (so i could delete and reconnect).