Nest 3rd Thermostat E can only be charged with USB

[PangPang]

My Nest thermostat can only be charged via USB after a thunderstorm with power outage.  This is the second one died in this way.  My heating system doesn't have a C wire.  I know the wiring works because I have 4 Nest thermostats, one for each heating zone.  All the other work except this one which is connected to both AC and Heating. The rests are heating only.   Every time, when this problem happened, I replaced the display unit, then it works. 

Now I ended up with two dead Nest 3rd gen displays.  But they work fine if I charge them with USB port, they just don't charge on the base anymore. 

My question is whether the hardware was damaged on those displays?  Can I still save them by using an external C wire adapter?

[Markjosephp]

Hello PangPang,

I'm sorry to hear that you're already having issues with 2 of your Nest Thermostat displays for not holding its charge. I'd be happy to take a look into this for you. 

In general, zoned system panels are compatible with Nest Thermostats. However, certain zone relay panels don't have enough power to charge the Nest Thermostat's internal battery. In this instance, power must be supplied to the Nest Thermostat via the Nest Power Connector or by connecting a common, or "C" wire.

Please take a look at this article and let us know if you have more questions.

Regards,
Mark

[Markjosephp]

Hey there,

I'm checking in. Still need our help? Let us know so we can further assist you.

Regards,

Mark

[Markjosephp]

Hi PangPang,

I'm checking in to make sure that you've seen my response. Please let us know if you have any additional questions or concerns before we close this thread in 24 hours. 

Thanks,

Mark