Thermostat continually disconnecting from Heatlink

[CMA_52]

I've had my Nest installed since 2017 and it's been working solidly fine since then up until a few days a go. Now the thermostat keeps loosing connection with the heatlink H71 error is shown. 

Nothing has changed in the locations or in the house, nothing new has been installed in between the 2 units, there is nothing that has changed, it just starts loosing connection to the heatlink. 

Most of the time it jus reconnects when I select the option to check again, other times it doesn't and I have to do the full reset link. I can't do the replace heatlink option as I have no 6 digit code on my heatlink for some reason (I guess the installer removed it?) Sometimes it stays connected for a few hours, other times a few mins. No pattern

Is my heatlink just faulty? or my thermostat faulty?

[Frustratedddd]

Can you confirm if you are connected to the router direct or via a mesh/hub/extender etc.?

Are you connected to the router via 2.4ghz or 5ghz, as 2.4 is more reliable.

Have you had any new appliance, ie microwave, car key remote and of course the good old air fryer or new phone even?

Issues can also happen from a neighbours appliances if very close.

I have found issues with BT and Virgin for some reason with Heat Link connection problems.

Suggestions really, but worth asking first.

[CMA_52]

Connected by Virgin router which hasn't changed for 8+ months, via 2.4ghz.

Had a new air fryer 12 months ago but no issues until this week. about 4m between thermostat and heatlink, with only wooden stairs and a plasterboard stud wall (no metal) in between them.

This is an older detached house so neighbours are quite far away with double garage in between us.

In a nutshell, nothing has changed in the past week.

 
I don't think it's a problem with my WiFi but a problem between thermostat and heatlink and the wireless comms they have I think, which I'm guessing is not through my WiFi but through its own system.

[TudorL]

By any chance, the thermostat display is on a wall or on a stand? If it's on a stand, you can try to move it a bit closer to the Heat Link and this may solve the issue. 

[CMA_52]

It's mounted on the wall so unable to move closer. But it has been there and working fine there for 6 years, that's what I find confusing. 

[AlexD]

Understood. Would you be able to check the power readings on the unit, possible low power readings on the display could cause it to disconnect. If you still have the H71 message, go to Tech info under the replace Heat Link option and access Power and let me know all the readings there. If it's connected at the moment it will be under Settings> Technical info> Power.

Did you notice any pattern so far like a particular time of day or anything of the sorts?

[CMA_52]

Battery 3.945v
Vusb 4.9v
Vin 0.00v
lin 200mA (c)

No obvious pattern at all. Very strange.

[TudorL]

Can you please also check the ms ping and the Signal Strength (SS)? You can do that by accessing Settings -> Technical Info -> Network. 

[CMA_52]

ms ping 1173

signal strength is 79
But when it does disconnect from the heat link the network connection is still fine as I can still see the thermostat through the app which shows the H71 error

[Vladut]

Can you please tell me what you see when you go to Settings> Equipment?

[CMA_52]

Your System

System boiler

Heat with On/Off

Hot water with On/Off

[Vladut]

Can you please tell me if you have the cover on the Heat Link?

[CMA_52]

It's intact with front and back parts fixed in place as it has been for 6+ years

[Vladut]

And if you check the bottom of the Heat Link can you see a screw?

[CMA_52]

Yep, I can see the screw

[Vladut]

Near the screw you should see the Heat Link entry key.

[CMA_52]

Nope, there's nothing there I looked all around the heatlink, even removed the whole unit from the wall to check the back.

[TudorL]

In that case, try to remove the front cover and there should be a code near the USB slot. 

[CMA_52]

Hi, cover removed and nothing by the usb slot

[LarisaL]

Could you please check the other side? The entry key should be near the other screw.

[Frustratedddd]

• Oh dear this is difficult!

The 6 digit code should be located in 2 different places.

1. By the Left hand fixing screw, NOT the side you show in the picture the other side!

2. Where you loosened the cover just by that screw ON the lid by that cut out!

[Vladut]

Hi @CMA_52 , just checking in with you. Do you still need help?

@Frustratedddd thank you so much for the input.

[LarisaL]

Hi there, just checking in! Have you seen the message from my colleague?

[TudorL]

Hi there and thanks for reaching our Community. I'm sorry to hear about your issue, but I'm here to help you out. Since you manage to have the display and the Heat Link reconnected pretty easily, the issue might be related to some interference. The devices are paired from the manufacturer normally, and when you first install it, they get paired before the heat link is wired on the wall. They maintain the connection as much as possible. In time, losing the connection can happen as they are connected via Nest Weave which is a Bluetooth based protocol which gets hindered by metal objects, glass, fish tanks and other large objects. It's only through the quality of the device that it stays connected as much as possible. Could you please tell me what is the distance between the thermostat display and the Heat Link? Also, please let me know about any objects that may come as interference: microwaves, cordless phones, even thick walls and metal structure might affect the connection. 

[CMA_52]

It is about 4meters from thermostat to heatlink. In the past 6 years nothing new has been built or changed in the vicinity, there is a wooden framed set of stairs and a stud plaster board wall between them, which has been there since before it was installed. 

All appliances are still in the same place they were when it was installed, so worked perfectly for 6ish years up until this last week.

Does the Gen3 use the same Nest Weave tech or does that use a better system?