Losing connection

[mjlo]

I've had my Nest thermostat for over a year now and am on the point of 'throwing it away' and going back to a wired thermostat or maybe a Hive, but that needs more investigation.  For several weeks it will maintain the connection between the thermostat and heat link then it will drop multiple times over several days before becoming stable again.  I'm now into day 3 of multiple disconnections which is the straw which breaks this camel's back.

Before installing the system I'd just assumed that the link between the two would be via my home WiFi so I installed a Mesh system to ensure a strong signal in all areas.  Only after installing the system I discover that it uses a network of its own, not home WiFi (heaven knows why?).

The only advice I can find anywhere is to reduce the distance between the thermostat and the heat link.  The problem is that the only area which is nearer than my hallway, where it's currently located, is the kitchen.  And the kitchen is the most stupid place to site a thermostat due to it it heating up whenever the ovens and hobs are in use.

Is there ANYTHING I can do before 'throwing it away'?  Please don't suggest I move the boiler and heat link into my entrance hall!  I believe the alternative Hive system can have a booster added to cure such problems.

Malcolm

[natwallbank]

I seem to be encountering a similar issue for the first time.  Noticed my thermostat was complaining it couldn't connect to the Heat Link a few days ago and have tried everything to get it to reconnect (resetting and restarting both Heat Link and thermostat) but haven't managed it so far.  Even when I move the thermostat into the same room as the Heat Link, so I don't think it has anything to do with distance / interference.  

it had worked without issues for over a year prior to this.

[AlexD]

Hi @natwallbank , thanks for sharing your experience. I am sorry to hear you are facing this behaviour from your thermostat and I would be happy to try and assist. 

How long has the thermostat been installed for and working before this behaviour occurred? Is the thermostat mounted on a stand or on the wall? 

[natwallbank]

Hi @AlexD - thanks for the reply.  The thermostat has been in place for around 2 years I think, and is mounted on the wall.  The disconnection from the Heat Link has never happened before, to my knowledge.

As mentioned, I've tried moving the thermostat close to the Heat Link (powering via USB) to see if it would connect, but no look so far. I've tried resetting the Heat Link, restarting the thermostat, etc. but nothing working yet.

[AlexD]

Thank you for the information. Just to check did you move just the display or did you also take the base from the wall that the thermostat attaches with? Also, when you took the display off, is the base connected to power using 2 wires in the T1 and T2 terminals or does it have a micro USB cable in it? 

[natwallbank]

I just moved the display, as the base is attached to the wall.  The base is currently powered by a micro USB cable.

[AlexD]

Thanks for letting me know. If you only move the display it will not be able to connect to the Heat Link. The display needs to be attached to the base when trying to connect to the Heat Link and power connected to the base. 

Make sure the display is placed back on the wall and first after all the re-connection options on the display you should see a Tech info section. Select that and go to power and let me know what the battery reading is and what the vusb readings are. Just to make sure the power is ok. 

Also, on  the Heat Link itself, what colour LED do you currently have on it? 

[natwallbank]

Ah okay, thanks - I did not realise that.  I've tried most of these steps with it wall mounted too, just tried moving it as a last resort.

My readings are as follows:

- battery = 3.948V
- vusb - 5.19V

As I say, it's been working fine for +- 2 years now, so strange that it's suddenly stopped.

The light on my Heat Link is slowly flashing blue, which I understood to mean that it's connecting.  

[AlexD]

Thank you for the information. The blue light indicates that the Heat Link is in paring mode and looking to connect.

Just to confirm, was the thermostat display or Heat Link replaced at any time in the past or is this the Heat Link and display that were always there? 

[natwallbank]

No, this is the same pairing since purchase

[AlexD]

Understood. In that case let me next log a few details so we can get a better idea of the situation. 

1. When was the thermostat installed?
2. When the unit was installed, did the display communicate with your Heat Link? If yes, how long after the installation did the issue occur?
3. In what order did the installer set up the device?
4. Was the display paired with the Heat Link when they were close to each other and then moved to the usage location or was it paired with the Heat Link from its usage location?
5.Have you had any recent power cuts in your area? If yes, has the error persisted since this power cut?
6. Has there been any recent work done on your heating system?
7. What is the distance between the Heat Link and Nest thermostat? Are the Heat Link and display on the same floor?

[natwallbank]

Apologies for the delay - here are the answers:

1. It was installed around June 2021
2. Yes, it's been working ever since and only lost connection recently, as far as I am aware.
3/4. It was paired when they were close to each other and then moved to the current location, but as mentioned - it's been working fine for two years.

5. No power cuts that I'm aware of at the time connection was lost.  We've had the odd one or two brief power cuts in the past year.

6. We had some new radiators installed, which involved turning off the boiler temporarily.  However the heat link appears able to still turn on the heating / hot water manually.

7. I'd say about 4 metres, but through a couple of walls.

@mjlo Apologies for hijacking your thread - I should have started a new one at the point it turned into a discussion. Hope you get a solution to your issue.

[LarisaL]

Thank you for the answers. Can you tell me if there is an error or message on the thermostat display at the moment?

[natwallbank]

It just says "failed to connect wirelessly to the Heat Link" (code H71) and when I "Check Again" it fails to connect. I've also tried to "Reset Pairing" with the same results.

I even tried re-adding the Heat Link (by inputting the code on the edge of the Heat Link) and that didn't work either.

[AlexD]

Thank you for all the information. Would it be ok if I reached over on the email associated with your account here so we can look further into this? 

[natwallbank]

Yes, of course. Sorry, been away from a computer all day today.

[AlexD]

No worries. I sent the email your way. As soon as you go through it and fill out the form make sure to let me know here so me or my colleagues can check for it. 

[natwallbank]

Hi @AlexD @Paul_R  - I just submitted my form now.  Thanks.

[Paul_R]

Thanks, I found it. I'll have to verify your email address, so please could you  go to this website: https://goo.gle/3Q8DDq0 . Sign in, and then it will ask you, Did you contact Google Support? Choose Yes to verify. Let me know when it's done.

[natwallbank]

Thanks - that's verified now.

[AlexD]

Thanks for reaching out here @mjlo . I am sorry to hear that you're facing difficulties with your thermostat and I would be happy to try and assist. 

You're correct, the connection between the Heat Link and display is done over their own communication protocol. This allows you to control the system from the display even if the Wi-Fi at the location is not active. 

If the disconnections happen intermittently that would generally be associated with interference from some source.

What I would suggests is to check and try to turn off any devices that could cause interference between the Heat Link and the thermostat display. Also check if there is any pattern to the disconnections, like a particular time of day or activity like streaming a movie, activating a particular appliance. 

Lastly, while you already mentioned that moving it would not be an option, if all the above has no effect I would recomend you do try and move it closer to the Heat Link, just temporary, to see if that does affect the connection. 

If from a new location that is closer to the Heat Link the behaviour stops, that would indicate that there is something in the area causing interference most likely between it and the Heat Link from the original position. 

[mjlo]

I'm lost!  I don't know who to respond to!  There are responses talking about a wall thermostat which I didn't ever mention and don't have.  T1 and T2 terminals etc.  Thanks to those who did think they were replying to me but I can't figure out who you are 😞

[AlexD]

No worries @mjlo . The T1 and the T2 terminals are on both the Heat Link and the thermostat base. They can be used to power the thermostat when mounted on the wall and wired to the Heat Link. You can check out the installation guide here with the wiring and examples. 

Just to check, could you confirm which model of the Nest thermostat you have and if it is on the wall or on a stand?

[Paul_R]

Hi there! Have you managed to complete the form from the email my colleague sent?

[Paul_R]

Thanks, it came through. Now, could you please try the following set of steps when you have the time?

Take the thermostat off the wall and also remove the base. Plug a micro USB cable into the base and then attach it to the thermostat and bring them as close as possible to the Heat Link, but no closer than 0.5 meters. Also make sure the cable is plugged into a phone charger and subsequently into a power outlet. This is only for the pairing, and you'll be able to put the thermostat back where it normally is afterwards.

Turn off the WiFi router, any active Bluetooth.

1. Reset the Heat Link by keeping the button on it pressed until the LED goes slowly pulsing blue (it takes about 30 - 45 seconds)
2. Take the thermostat off the base and give it a restart, off the base by holding the display and the back of the thermostat pressed for 10-12 seconds. (Hamburger reset) 
3. While the thermostat is restarting, do not put it back on the base yet, but instead, reset the Heat Link again just like before.
4. After the Heat Link is reset, put the thermostat back on the base when it asks you to do so on the screen. 
5. Go to: Replace Heat Link (underneath the H71 error code) and enter the 6 character entry key from the Heat Link, but do not connect just yet.
6. Restart the Heat Link twice (1 restart is a 10 seconds press, until the LED goes off once). 
7. Press connect on the display.

[AlexD]

Hi, did you see my colleagues message? make sure to keep us posted here once you try the steps. 

[natwallbank]

Hi Alex, I did - thanks.  I just haven't had chance yet, it'll likely be this weekend so I'll let you know how I get on. Thanks.

[AlexD]

No worries. Just make sure to keep us posted once you do. Have a great weekend ahead! 

[natwallbank]

Hi,

Just to let you know that I followed the steps above at the weekend and it is now happily connected again.

I restarted the thermostat close to the Heat Link (while still on the base, which was powered via USB) and that seemed to be enough to fix it.  I've moved it back to its original location, and it's been happily connected since.

Thanks!

[Paul_R]

Hi there, just checking in. Do you still need our assistance?

[TudorL]

Got it, thanks for letting me know. Would it be okay to send you an email on the address associated with your Community account? 

[UanaC]

Hello there! Just checking in with you. Did you see my colleague's previous message?

[UanaC]

Should anything else come up, please message us again and we'll take it from there. Have a good one and stay safe!