H71 Error, Help!

[RyanDavies]

Hey folks, 

I have the 3rd generation Nest thermostat, I’ve had it since January 2020, it’s been working fine until this weekend, the thermostat keeps losing its connection to the heat link giving me the H71 error.

When this happens some times it reconnects after 30 or so minutes, other times it’s been disconnected for hours then randomly it’ll connect again and boom, an hour or so later it looses its connection again giving me that H71 code.

The thermostat itself hasn’t been moved, it’s in the exact same place it’s always been but I’ve even tried moving it closer to the heat link and sure, it’ll connect back up but still disconnects randomly even if it’s literally within a meter of the heat link.

I’ve tried factory resets on both the heat link and the thermostat, I’ve re-paired them again and again, the issue still remains, I’m 90% sure this is a hardware issue with either the heat link or the thermostat but before I go and replace it, has anyone else come across this issue?

[Dannybliss]

Having the exact same problem! Been happening for a couple weeks at least 3 times a day. There seems to be absolutely no solution that works 

[AnaM]

Hey @RyanDavies and @Dannybliss,

I'm sorry to hear about your issues, but I'd like to help you out. To begin with, I'd like to see a picture of the power readings which you can find on the thermostat's display in Settings> Technical Info> Power and a picture of the network details, which can be found in Settings> Technical Info> Network. If we're not able to isolate the issue based on these values, we'll do some troubleshooting steps.

[RyanDavies]

 

Here you go, it’s actually connected and working as normal currently, I had read about a power issue but when mine is disconnected the power readings were as they should be.

[AnaM]

Thank you @RyanDavies,

The values look good. Please answer the following questions:

• What is the distance between the Heat Link and Nest thermostat? 
• Are the Heat Link and display on the same floor?
• Did you notice a pattern in the connectivity issues? 
• Do you have many Bluetooth devices that could cause interference?
• Has anything changed in the environment lately?
• What's the LED on the Heat Link when it disconnects from the thermostat?
• Have you had any recent power cuts in your area? 
• Have you recently had service or maintenance on your electrical, plumbing, or heating system?
   

[RyanDavies]

The distance is about 5 metres.

They’re on different floors.

I didn’t notice any pattern.

I have a couple of Bluetooth devices (keyboard and mice) but I’ve had these for years, no previous issues, still used in the same place.

Nothing has changed in the environment.

The heat link LED is yellow when it disconnects.

No power cuts.

Boiler was serviced last month but I don’t see how that could have caused what appears to be an incredibly intermittent issue.

To give you a little more info, the day after I made my original post it connected and was relatively issue free for the last week then again yesterday it disconnected a couple of times, it’s been fine since. I did notice the heat link connectivity percentage was fluctuating up and down randomly yesterday.

 

[AnaM]

Thank you for all the information. Let's try the following:

• Restart the thermostat by going into Settings> Reset> Restart.
• Reset the Heat Link by pressing the button on it for 20-30 seconds.
• Disconnect the thermostat from Wi-Fi for 24-48 hrs and monitor the connectivity with the Heat Link.

Let me know how it goes.

[CristianC]

Hi there. Just checking in. How's it going with your thermostat? 

[Dannybliss]

It has literally just done it's weekly h71 error right now 

[AnaM]

Hey @Dannybliss,

I'm sorry to hear about that, I'll do my best to help you, can you also send me a picture of the power readings which you can find on the thermostat's display in Settings> Technical Info> Power and a picture of the network details, which can be found in Settings> Technical Info> Network?

[CristianC]

Hi there. Just checking in. How's it going with your thermostat?

[CristianC]

It's been a while since this thread was last updated so I'll go ahead and lock this thread. If you're still experiencing problems, please feel free to start a new thread and we'll be happy to help.