Nest Ver 3.4 Thermostat disconnects from network when it goes to sleep

[dale2306]

I have read about all the possible reasons that my Nest Thermostat Ver 3.4 could be going offline and I have debunked all of them.  The battery is above the minimum voltage required.  I have 30+ devices attached to my network including 12 Google Home devices and if I have network issue this is the only device having it.  It has a -55 dBm signal reading.  I also have a Yale lock on a Nest Connect and it has never gone offline.

I have investigated this at length.  The simple fact is that the thermostat goes offline when it goes to sleep.  I have sat where I could observe the Thermostat while not having it sense my presence.    As soon as the display goes out my thermostat goes offline.  As soon as the display comes back on it re-connects immediately.  On a computer if I tell it not to put the WIFI connection to sleep it stays connected and I can wake the computer remotely.  If I let the WIFI connection go to sleep I can't connect to the computer remotely.  I'd be willing to wager this problem started occurring after a software update to the thermostat that also included some power saving settings.

I could be wrong and if I am please give me another explanation that makes sense.

Thanks

[Patrick_Caezza]

@dale2306 

How is it wired?

Does it have a C wire?

[dale2306]

The installation instructions never asked me to connect the "C" wire.  I installed the thermostat years ago and for the first few years it worked fine.  If there was an issue with the wiring I should have had this problem right from the start.  This issue just started about a year or so ago.  During this issue I twice removed the thermostat and charged the battery using the USB jack on it.  The problem occurred again as soon as it went to sleep after I put the unit back on the mount.

[Patrick_Caezza]

@dale2306 

This type of problem can take several years to show itself, It has to do with how the thermostat keeps its internal battery charged.

The best solution is to install a C wire by using a spare wire if one is available or installing the Nest Power Connector.

[dale2306]

Can I use this?

https://www.amazon.ca/gp/product/B07DJ7RHS5/ref=ox_sc_act_title_1?smid=A1LYXSJE9Q28E0&psc=1

It's a lot less expensive than the Nest one.

Thanks for the replies.

[Patrick_Caezza]

@dale2306 

Yes, you can.

Just connect one wire to the C terminal and the other wire to whichever R (Rc, Rh) terminal you are not using.

[dale2306]

Hi Patrick,

Rather then adding a transformer I discovered that my wire coming from the furnace had 4 leads and since I have no Air Conditioning I was able to move the Y1 wire on it to the "C" terminal on the furnace and the thermostat.  The Thermostat equipment now shows that the "C" wire is connected as the 24V common.  After a few days the Thermostat still goes offline when it goes to sleep making me very happy I didn't spend more money on the issue.  It comes back online immediately after I wake it up.

[dale2306]

It would be obvious to anyone like me that spent many years in the computer and electronics industries that either the software for the thermostat is putting the network to sleep when it puts the thermostat to sleep or there is a defect with the thermostat itself.  Either way Google should be figuring it out and fixing it or replacing my thermostat.