Thermostat keeps disconnecting from Heat Link

[skoobaskunk]

Logged a case with Google Support via e-mail 5 days ago under case reference 7-2527000037813 and as I've yet to receive any assistance thought I would follow up here to see if someone can help.

We own a 3rd Gen Google Nest Thermostat that in the last week has been consistently dropping its connection to the Heat Link which is connected to our boiler and the app is displaying a H71 Error code.  The Thermostat and Heat Link have been happily connected together for a while now and nothing has changed within our property,  so nothing new should obscuring or interfering with the connection between our Thermostat and the Heat Link.

I have been through the following troubleshooting steps:

• Rebooted router
• Reboot our WiFi AP’s (independent of our router)
• Rebooted both Thermostat and Heat Link (the latter has an amber light when not attempting to pair it to the Thermostat)
• Assigned a static Ip address on my router via MAC address association
• Power cycled both thermostat and Heat Link
• Reset the Heat Link (Flashing Amber Light>Flashing Blue Light)
• Reset the connection between Thermostat and Heat link and attempted to re-connect via the I automated process and by adding a 'new’ Heat Link via the 6 digit code on the underside of the Heat Link
• Moved thermostat within a foot or two of the Heat Link

Thus far nothing has worked and we have a cold house with young children at home so really could use some assistance please.

Thanks.

[Frustratedddd]

You don't mention anything about a factory reset, have you done that?

Are you connected via a wifi booster or mesh system?

Any new appliances in the home, ie air fryer, microwave, or relocated anything metal?

Why would you do this?

Assigned a static Ip address on my router via MAC address association

[skoobaskunk]

Yes, the factory reset has been performed.

No Wifi boosters, but I do have a Mesh network...the same Mesh Network that I was using when the Thermostat was working correctly, but the issue seems to be the connection between the Thermostat and the Heat Link, does this use WiFi?  I was under the impression that the Thermostat and the Heat Link used a different communication protocol to communicate to one another?

No new appliances introduced that would be interfer.

Why would you do this?

Assigned a static Ip address on my router via MAC address association

Other posts on the community forum suggested assigning a static IP address resolved their issues, albeit that appeared to be related to internet connectivity.

[Frustratedddd]

No the connection from Display to Heat Link does not use you wifi network, it uses it's own mesh type system. That's the reason I ask if you are using a mesh wi-fi system, [Unifi are the worst for conflicts] as they do conflict at times. You may have been using the same connection for a long time, but that does not always mean a guaranteed connection. 

I would check to see if the thermostat is connected via your AP, and if so change to direct to the router. This has always been the recommended way of connection. Conflicts can even happen from neighbours equipment or items they have in their homes. We even had one that conflicted with the users new mobile phone, another with the users electric car charger. [No new Dect phones at all?] Having said all that, dropping connection from Display to Heat Link is usually an obstical issue blocking the signal.

I would do a factory reset, then reset the Heat Link correctly on it's own, and then reset Display correctly on it's own. Belt and braces job really. Details for that can be found on many of my replies to people. Make sure you reset correctly, not like a lot of people do.

PS...The other option if you are NOT wired just wireless from Display to H/L is install a cable between the 2.

[skoobaskunk]

Sorry, not sure what happened to last nights reply.

I only have a wired router (Draytek 2927) with an Enterprise Grade WiFi set up (5 Nodes - Zyxel Multy Plus WSQ60).  I was intending to run this WiFi solution so didn't see any point investing in a router with integrated WiFi when that would have been turned off right out of the box.  

We no longer have landlines in our house since we switch to full fibre internet about 4 years ago, so our DECT handsets were removed at that point.

I will check your post history to see if I can locate your specific reset instructions and will report back, going to try and spend some time with it this morning.  In term of hard wiring the 'puck' to the H/L I did investigate this, but a couple of the first videos that I came across stated that this was only for voltage supply to via T1 and T2 and not for the relay of heating commands?   

[Frustratedddd]

The reset for the H/L is this...........Press the button for over 35 seconds, until you get a steady pulse, just keep it pressed for about 44 seconds to confirm - Do that twice

To reset the display....Remove from base - Squeeze the display like you do a handburger until you see the little house then release. Do that twice.

When theye are done, setup as you normally would.

The DECT idea was another solution, but worth looking into anything that might have changed. We even found someones new metal gates had caused an issue!!!

The videos are incorrect, the T1&T2 connections are 12v supply, but also give control. I ONLY use a wired setup from Display to H/L, you will then notice another glitch in the system if just wired. Should you be using a System boiler [Combi obviously not], then if the water is called for the icon will go orange the same as the temprature one does. Wireless does not allow this,and only shows ''On''. I have been asking Nest when they were a good company to sort that out, but since Google took over, they are not the slightest bit interested.

[skoobaskunk]

So earlier today I disconnected the 'puck' removed from its location on the panelling that boxes in the space under our stairs in our hallway and took it up to the loft (where my combi boiler is located) and got it within a foot of the H/L.  I ran through the reset procedures contained in this thread that you also commented on https://www.googlenestcommunity.com/t5/Nest-Thermostats/Nest-gen-3-learning-cannot-connect/m-p/65595... and the puck still wouldn't connect.  I then connected it via T1 and T2 and it came to life and connected as per your expectation.  

I ran the boiler to heat the house a little before taking it downstairs, where it has been connecting and disconnecting for most of the day, so I've taken the decision to try and hardwire the thermostat, which is going to be a job for next weekend, IF I can find a route down from the loft for the 12v cable, not going to be easy, but I'm going to give it shot.  I have a roll of old Cat 5e wiring and was tempted to temporarily use this before investing is some wiring with better shielding, assuming I can find a route down.  Not sure if that cable would be sufficient or suitable for a temporary in situ test?  Also, given the distance between the boiler and the puck I'm hoping that the wiring won't be too long and cause a voltage drop over a longish distance?

As an aside, I suspect that I know what might be causing the issue/interference in case you continue to generoussly assist others in the future.  Back in February we had new smart meters installed for our gas and electricity supply, which I believe use Bluetooth to communicate with the smart display, and use a mobile/cellular signal to report back to the energy suppliers.  We had a relatively mild winter this year and I tend to set the thermostat to off from the app whilst not is use.  It's been in that state until about a week ago, and it's only since putting the puck back it into normal/heating mode that I can visibly see it connecting/disconnecting, not sure if it would do this in an 'Off' state?  This is the only change that I can think of that may be causing interference as there aren't any new obstacles or other new devices in the house that would be blocking the signal.  A hunch, as I can't turn off the meters (as much as I'd love to...permanently 😉) to prove this, but just thought I'd mention it to aid the troubleshooting for other users, or anyone else that may come across this thread. 

Will report back after the weekend.

[Frustratedddd]

Cat 5 has 8 cores, and if you join the cores for one connection and the same for the other connection should be OK. After all it’s only 12v. Volt drop shouldn’t be an issue as the cores joined as mentioned will give you a good 1mm plus. After all the average install uses nothing bigger than 1.0mm.

I would probably do a temporary bodge job to see if all works before a correct install. Even if you run the cable direct from the roof down the stairs for example will prove all good. You probably will not get praise from the lady of the house, but better temp job before committing final install. 

Yes you might well have found the problem with interference with the meter. Like I mentioned, the oddest things can cause an issue, and that signal could well be the problem. You could remove the remote smart meter display, put it next to the meter to eliminate interference as a trial. Sadly I’m totally against smart meters after being in the trade for 53 years, and seeing many meter readers loose their jobs!  I don’t have good word for them, but that’s another topic! Try the monitor replace location , and see if that helps. Good luck.

[skoobaskunk]

To close this query/problem out.

Replaced the Heat Link with a new one that was purchased on eBay and the same problem manifested itself.

Asked EDF if they could shut off our smart meter data transmission functionality to facilitate testing, they said they could, but wouldn’t be able to turn it back on again and we’d have to go back to submitting readings.  So stood them down.

Anyway, long story short, found a route down from the loft to the thermostat in the hallway (passable, but not ideal) and both are now physically connected by 0.75mm flex and the connection, as you’d expect hasn’t faltered since.

Not to self, tidy up the wiring the next time the stairs/landing carpet needs renewing and don’t bother with a wireless thermostat again in the future…not worth the hassle.

Thank you for your help, assistance and guidance @Frustratedddd much appreciated.