H71 error on Thermostat

[JDav]

Hello. My Google Nest thermostat is  reporting it has "Failed to Connect wirelessly to the Heat Link" (H71 error).  I've checked the heat link, which is receiving 240V power, no lights at any time, and nothing happened when trying to reset to factory defaults.  I've tried providing 5v power via the micro-usb and this works, the leds are on, and the button is able to cycle the operating mode, but no relays to actually turn on the boiler.

i believe this indicates a power supply failure in the heat link, with no 5v or 12v available.  

How can I obtain a replacement Heat Link?

[Angman]

Hi contact google support and they will give you a reference number and a link to BOXT who will supply and fit a new one

[sicsacol]

Hi @JDav,

Thanks for posting in the community forum. I'm sorry to hear you're having difficulties connecting your Heat Link to your Nest thermostat. I understand it can be frustrating when your device isn't working as expected. Don't worry, I'm here to help. To better assist you, I have a few questions:

• What type of thermostat do you have? To check it, please visit the next article: How to tell which Nest thermostat you have
• What's your Heat Link's light? 
• Did you experience any power outages before the issue started?
• When did this issue first occur?
• When was it installed?
• Did you try to take the Heat Link out of Manual Mode? If not, you can do so by pressing the Heat Link’s button once. When the two bottom green lights are off, the Heat Link is out of Manual Mode.
• Please share a screenshot of the error displayed on your Nest thermostat.

I appreciate your troubleshooting efforts. Please let me know the answers to these questions, and I'll be happy to help you further.

Sincerely,
Jonathan