Nest Thermostat E sporadic & self-resolving H151 errors

[Stevec9]

I have 2 Nest Thermostat E's which control 2 separate underfloor heating zones in my home.  Most of the time they work perfectly fine,, but every so often (sometimes once a month, sometimes more frequently) one or other of them seems to lose its connection to the HeatLink and displays a H151 error.  When this happens I do one of 2 things to resolve it:

1. Go through the troubleshooter which suggests to restart the HeatLink, sometimes getting as far as having to factory reset the Heatlink before it will reconnect

2. Do nothing,  and after a few hours it will reconnect itself automatically

When it's working fine, the signal strength reported on the Thermostat is between 75 and 85 which is apparently "strong". This leads me to believe that there is something that happens in my home network which causes the connection to be lost.

What can I do to debug what the problem is? (Not restart/reset it, as per above it can fix itself without this so doing that is clearly just a "sticking plaster"). 

Reading between the lines it appears that

• it's the Thermostat E which connect to the wifi.
• The Thermostat E then connects to the Heatlink via the Weave network

If that's right perhaps the two Heatlinks are conflicting with each other? Or does the Weave network allow them to create a mesh?  I also have a number of Nest Protects - do these participate in the mesh?

[sicsacol]

HI @Stevec9,

Thanks for reaching out in the community. I'm sorry to hear your Nest thermostats keep disconnecting from your Heat Link. I understand it can be frustrating when your devices aren't working as expected. No worries, let's work together to fix this. To help me with that, I have a few questions:

• What is the color of your Heat Link's light?
• How is the Heat Link being powered?
• When was the thermostat installed?
• When the unit was installed, did the display communicate with your Heat Link? If yes, how long after the installation did the issue occur?
• Have you had any recent power cuts in your area? If yes, has the error persisted since this power cut?
• What is the distance between the Heat Link and Nest thermostat? Are the Heat Link and display on the same floor?
• Please share a picture of the thermostat displaying the error code.

I appreciate your troubleshooting efforts and the information shared. Any additional details you can provide will be helpful.

Regards,
Jonathan

[Stevec9]

Hi Jonathan

Thanks for getting back to me.

• When either or both of the Thermostats is showing the H151 error, the HeatLink's light is off by default, and if I click the button it shows green
• The Heatlinks are powered from the mains electricity
• Once was installed in 2019, one in 2021
• Yes, they both worked fine when they were first installed.  I can't remember exactly when they started having the sporadic H151 errors, but it now happens once a month or so
• No recent power cuts
• The Heatlinks are both by the boiler, one of the thermostats is 4 away, the other one is 10m in the opposite  direction
• I don't have a picture of the error, will capture it next time.

To be clear, the H151 error happens sporadically to one or other of the thermostats and then resolves itself after a while without me doing anything.

I'm reasonably technical, so if there is anything further I can do to resolve this when they are showing the error I'd be happy to investigate.

Thanks,

Steve

[sicsacol]

Hi @Stevec9,

Thanks for your reply. I really appreciate the information shared.

Let's try the following steps together:

• Make sure your Nest thermostat is connected to the base.
• Verify that your display has a secure connection to its power source (micro-USB cable and a power outlet or the T1/T2 wires).
• On your thermostat, go to Settings > Technical info > Power, take a picture of the information displayed, and share it.

Please keep me updated on how it goes.

Sincerely,
Jonathan

[Stevec9]

• Yes, attached to the base
•  Yes, plugged into USB power supply
• Photos here:  https://share.icloud.com/photos/0349VMkuypC3gWdeLsOHTWgdg 

Thanks!

[sicsacol]

Hi @Stevec9,

Thanks for replying. I appreciate the picture. 

The power reading seems to be fine, so that's not the problem. Can you confirm:

• Are there devices or appliances (such as baby monitors, microwaves, cordless phones, etc.) near the thermostat?
• Have you tried resetting the Nest Thermostat E?
• Have you tried restarting your router?

Please keep me updated on how it goes. 

Cheers,
Jonathan 

[Stevec9]

Hi Jonathan,

Thanks for your continued assistance.

 - there are no devices in between one of the Thermostat Es and it's HeatLink.  The other one has a microwave and oven between it, but given that it works most of the time I can't see that this would be a problem.  Is there a way to see the signal strength between the devices?

 - I have previously reset the Thermostat E, which resolved the issue temporarily but as it happens repeatedly this isn't a practical solution

 - The router resets automatically on a weekly basis

Are there tools I can install or setup which will help me debug this when it happens? Or any way I can get information from the Thermostat E to help understand why it cannot connect?

Thanks,

Steve

[sicsacol]

Hi @Stevec9,

Thanks for the update.

My team would like to know more about this behavior with your Nest thermostat. When you get a chance, please fill out this form. Let me know when you’re finished. We’ll have someone reach out to you via email from there.

Let me know once the form is submitted.

Regards,
Jonathan 

[Stevec9]

Hi Jonatham,

That link isn't working for me, I get this error:

Looking at the raw response in Chrome DevTools I see this

"submit_error": [
        {
            "code": 22,
            "sub_code": 4,
            "escalation_rpc_event_id": "62E8480261264.5630F70.B516518E"
        },
        {
            "code": 6,
            "error": "CUF Submit Pv2.CreateEmailCase:FAILED;hc:googlenest;form:nest_community;rw:11103743;u:534094234082;code:9;error:com.google.apps.framework.request.StatusException: \u003ceye3 title='FAILED_PRECONDITION'/\u003e generic::FAILED_PRECONDITION: The request is ineligible. Follow go/case-creation#eligibility to resolve."
        }

Seems like my "request is ineligible" ??

Thanks again

Steve

[sicsacol]

Hi @Stevec9,

Thanks for the update.

I'm sorry to hear the link didn't work. No worries, please try this form. We're experiencing an issue with the regular form link, so this alternative link is from the Pixel Watch team. However, once we receive your form, we'll redirect it to the Thermostat team. Please provide the requested information (community username and thread link).

Let me know when you’re finished.

Regards,
Jonathan 

[Stevec9]

Done - thanks

[sicsacol]

Hi @Stevec9,

We've received your form and appreciate the details you provided. Please keep an eye on your email, as someone from my team will contact you shortly to help. If you have any questions or concerns in the future, feel free to reply to this post.

Cheers,
Jonathan

[Stevec9]

To close this thread, I had a conversation in response to the ticket I created, which unfortunately didn’t help at all. Disappointingly it appears that there is no way to diagnose connection issues between the Thermostat E and the HeatLink.  The only advice I was given is to move the HeatLink around, but since the problem is sporadic that’s not an answer.

I’m disappointed there’s no signal strength indicator, and no way to see why it has lost the connection. I’d say these are standard features nowadays, especially for higher end products like Google Nest.

I have no choice but to put up with the sporadic disconnections.

[gmpify]

I am having the exact same behaviour on one of my thermostats.