Replacement Nest Thermostat failed to pair with existing Heat link

[KenChong]

Got a replacement thermostat as old one had battery charging issues.

Followed the instructions given by google to try and link the new thermostat to the old heat link but nothing works. Tried everything available (30-45second long press on heatlink and pair,  reset heatlink twice pair which still doesn't work)

Also made sure no interference, bluetooth, wifi all off. And took old unit way out of house which does not seem to help.

Any ideas to help pair the new thermostat to the old heatlink?

[Frustratedddd]

I think a little more searching could have found your problem, but having said that you have tried!

I assume you now see an error screen with H71, correct?

[KenChong]

"A little searching would have found the problem"

Turns out I needed to change the whole system after consulting with Google over phone.

Happy for this thread to be closed. Thanks

[KenChong]

Happy for this thread to be closed. Thanks

[Frustratedddd]

Did they advise when at the error H71 to choose “ Replace Heat Link”, reason being you have a none matched pair due to you swapping the display!! That’s the only way to pair, not by your suggestions above.

[KenChong]

Yes, and it did not work. 

[Frustratedddd]

Did you also reset the heat link with over 35 - 40 second press and twice? Not 30 seconds as most people advise ? Did you also reset the display when removed from the base plate, and did that twice?

[KenChong]

Yes I did, I did all that after searching through this nest community, even made sure the 6 digit link of the heatlink was correct outside and inside the case, nothing worked. 

Called Google today and they could not explain why it was not working and recommended a new unit altogether hence why the technician came

Sometimes it just does not work.