Can not hook up to Nest App for 7 digit code

[trooper0169]

ModelT3007EF Nest Learning Thermostat.

I get to the Nest App display on the unit it states low battery I push the bottom of the dial not happen Will not do anything or display any code for my android 11 phone. The unit is hooked up to my internet.

[CoolingWizard]

Hello Trooper0169,

Please take a picture of the nest back plate so I can see which wires are hooked up to it and if you still have the copy of the picture of the old thermostat wiring plate before you replaced it so we can see both of those. If you do not have a power common wire installed, the battery may be too low and what it does is it disable certain features and capabilities, including disabling Wi-Fi, and sometimes it shuts the display off when it gets extremely low. Now we can hopefully do something to help like this. Pull the display off the base and turn it over and you’ll see a micro USB port, plug it in and charge it up full overnight then place it back on the base and you’ll see if that the display will probably be working and you’ll be able to finish setting up your android device.

The AC Cooling Wizard

[trooper0169]

[trooper0169]

I have also plugged it into a USB

[CoolingWizard]

Based on the pictures, you did not wire your nest the same way that your old thermostat was wired.

Your Nest should be wired with the following color of wires and what terminal they should be on:

Red Wire —> RC (Move from RH)

Black Wire —> C (Move from Y1 and put here)

White wire —> W

Orange wire —> Y1 (move from W2, put here)

Green wire —> G

once you make the wire changes, your HVAC system will charge your nest thermostat.

The AC Cooling Wizard.

[trooper0169]

I did not wire it up. The furnace installer did it today. All the other functions work. But the WIFI also disconnected also now.

[trooper0169]

I charged it up for an hour or so (with the USB on the back)and I got it to hook up to WIFI again and then the Nest App on my android 11 phone. If it shows Low Battery again I will call the installers and have them check their wiring as per your instructions

[trooper0169]

BTW my old thermostat was a Honeywell Pro Series Model TH6320WF2003. Maybe they are wired differently. It also could hook up to the internet for GEO setting while you were away from your home.

[CoolingWizard]

Thermostats are not wired differently. Basically all thermostats have the same functions defined, including programmable ones and non-programmable ones. Anytime there is an R wire that is an incoming power for the thermostat. The reason some thermostats have an RH and an RC is because sometimes heating systems are completely separately controlled from cooling systems.
So the letters on each of the terminals are the same function in every thermostat. So, unless they change the other end of the cable in your furnace and your outdoor air conditioner, for example, those cables will not have been changed when the Nest was installed. So if all he did was remove the old thermostat and put the new Nest thermostat on, he did it incorrectly.
You can simply make a change by removing the wires and inserting them in to the correct terminal. To do this, Simply press the outer tab edge of the orange wire and gently pull it out, then then gently push the outside tab on the black wire in Y1 and slowly pull it out. Press the outer tab in the C and insert the black wire there. Now take the orange wire press, the Y1 tab down and insert the orange wire there.

The black wire is your power common wire and if you do not swap the orange and black wires, then your thermostat will not maintain its charging of its internal Lithium Ion battery.

The AC Cooling Wizard

[trooper0169]

They switched out the furnace also at the time of installing the new Nest unit so I don't know if the wiring was changed at the new furnace. The low battery message is not showing on the unit this morning. Everything I think is now working and it even did an "updated itself" and I can control the furnace through my android phone.

Now shows "Nest APP Connected" I will wait to see if the battery loses the charge again. They might have changed the wires at the furnace. If it loses charge I will do the switch as per your instructions. Thank you for all your help.

[CoolingWizard · Accepted solution]

If as you say, they changed the equipment they might have changed the wiring. I would not make the changes I suggested. What I would do is simply ask the contractor if they did indeed change the wiring at the new furnace end. Tell him you noticed that the two wires are switched. Let them know you were looking at the two photos of before and the after, and you notice that the black wire and the orange wire are not in the same positions.
But here’s the deal, the two wires that have been changed. Neither is part of the original heating, in fact, the two wires are common and compressor contactor control so if it’s wrong, what will happen is 1, your your thermostat will not be charging, and 2, in the summertime when you turn the air conditioner on, you are going to blow a fuse or burn out the transformer when R is connected to C via Y1 wire a direct electrical short will be made. With your contractor and specifically have them answer the questions did they change the wiring between the thermostat and the new furnace?

The AC Cooling Wizard

[EdwardT]

Hi folks,

@CoolingWizard, thanks for the help!

@trooper0169, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

[trooper0169]

I had a furnace company tech come back around and explained how no common wire was attached to the Nest thermostat to charge the unit. He 1st checked my new furnace wiring and then hooked a wire up to the "C" input. My app says now that it is charging I believe at 24 volts. Thanks for all your help.

[EdwardT]

Hi trooper0169,

Thanks for the update. I'm glad to hear that it's working fine. Please observe it for now and let us know if anything comes up.

Thanks,

Edward

[EdwardT]

Hey trooper0169,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Thanks,

Edward

[EdwardT]

Hi trooper0169,

I'm just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,

Edward