NOTE: check you software version on your Nest E (in Google Home select Thermostat, then Device Information.) If you have SW version: 6.1-9 then see here (https://www.googlenestcommunity.com/t5/Nest-Thermostats/6-2-22-Software-Update-Issues/td-p/33005)
I am getting an E44 error code for the last few days as reported in other messages (after updating to Android 12?). Also, I saw on the Google list there is no E44 but here (https://www.thermostatforums.com/showthread.php?85-Nest-thermostat-error-codes) it is reported as:
"E44: Your Nest either has wires that aren't fully inserted into the connectors or has tripped an internal fuse. If a internal fuse has tripped your nest may need to be replaced"
There are reports of a recent Firmware update that may be the cause. No other mention of this "internal fuse" (above). In most reports the customer did a lot of fiddling with heating system, moving wires around and their conclusion was the Nest thermostat failed.
My Nest Thermostat E works for a day or so, then reports "E44: Contact Nest support". I've checked all the wires and they are attached and have not been disturbed since installed 12-2019. Here is a screen shot of the Error Message on a Pixel 5 fully updated (https://imgur.com/a/1ECb9AI). Here is a photo of the Nest E thermostat face with error message (https://imgur.com/a/K6Q2D3b). At first I was able to take the Nest E display off the wall and when I put it back on it worked OK for a day or so. Looks like it is now stuck reporting this error and I cannot access via phone or device.
Spoke to a Nest rep, he confirmed the E44 error exists. Gave him all my thermostat system info. He was to call back this morning to try moving some wires, but he hasn't called. Unit is seems to be getting power with heat on - Battery 3.9 V, VOC 32.6V and VIN 33.6; lin 200 mA(c). When the heat/fan was off the only power change was lin 8mA(o). I am assuming the "c" is the "common wire" which in my system is Brown (others report Blue). Not sure what the "o" after lin 8mA means. This was the info the Nest Rep asked for off the face of the thermostat after scrolling down to "Tech" below error message on screen.
Here is how my Nest E is wired and Google Nest E wiring diag. (https://imgur.com/a/QgxZnHB)
As this happened suddenly, with no changes to my heating system (no AC) it seems like the thermostat has failed after 2 years. Any thoughts would be appreciated.
