topic No Power to Y1 Neat Gen2 Learning Thermostat in Nest Thermostats

No Power to Y1 Neat Gen2 Learning Thermostat

Ricolow — Tue, 31 May 2022 21:33:49 GMT

Old Gen2 Nest was reading incorrect (84 degrees, but was actually 74) inside temp and AC wasn’t getting cold. Technician came out and checked AC - no issues. Tried replacing Nest to Gen3 - wouldn’t go on. Put old Nest Gen2 back on - now get error message E30 “no power to Y1 wire detected”! Appreciate any help/suggestions.

Re: No Power to Y1 Neat Gen2 Learning Thermostat

CoolingWizard — Tue, 31 May 2022 23:17:38 GMT

The Y wire is what calls for cooling. The thermostat connects the incoming power on R, to Y to initiate cooling. Do you have a Volt Ohm Meter? Your generation 2 can operate on the R and Y wires to receive power and charge the internal lithium battery when there is not a C wire. Did the HVAC technician remove your nest thermostat and check the voltage available? There needs to be a minimum of 17.1VAC between R and C at the Air handler. Can you post a picture of the nest wall plate showing the wires?

Did you change the wall plate from the Gen3 box when you tried to upgrade?

Re: No Power to Y1 Neat Gen2 Learning Thermostat

Ricolow — Wed, 01 Jun 2022 00:03:50 GMT

Yes, charged new Gen3 plate. Also tried reinstalling Gen2 and got same error! Not sure how to attach photo, but have yellow wire to Y1, blue to Y2, black to Rc, red to Rh, and white to W1… same set up as before.

Re: No Power to Y1 Neat Gen2 Learning Thermostat

CoolingWizard — Thu, 02 Jun 2022 17:37:16 GMT

The color of the wire used, for the most part is irrelevant. What matters is that the same wire at the thermostat is connected to the same function terminal in the air handler. For convenience sake, HVAC companies tend to put the red conductor on the R terminal. A green conductor on the G terminal. A white conductor on the W terminal and the yellow conductor the Y terminal. When a heat pump is used, a wire is put on O/B.

Did you note which colored wire was connected to which terminal in your original non-nest thermostat? You might need to to go look at your air handler and double check which colored wire is on witch terminal of the control board. So here is some help.

Rc is input from the 24V AC Cooling transformer.
Rh is input from the 24V AC Heating transformer. (Not needed unless separate heating system ie., Boiler system)

Y or Y1 is for stage 1 cooling.
Y2 is for stage 2 Cooling

W or W1 is for Stage 1 heating

W2 is stage 2 heating.

E is Emergency heat, typically used with heat pump systems.
G is blower Fan

O/B is the 4-way Heat Pump reversing valve.
C is out/return to to the common side of the transformer

Do you have access to a Volt Ohm Meter? If so, set the meter to measure alternating current. Then attach one lead to the red wire, and then the second lead connect to each of the other remaining wires until you reach a voltage that will be between 17 and 27 V AC. That wire will be your common wire. The red wire will go in Rc, and the common wire into C. I will need more information to guide you with the remaining wires.

Re: No Power to Y1 Neat Gen2 Learning Thermostat

MelbaDT — Thu, 16 Jun 2022 01:31:27 GMT

Hey folks,

Thanks for helping here, CoolingWizard.

Ricolow, I'm jumping in to ensure everything is covered here. Have you had the chance to try the suggested wiring guide above? If yes, how is it?

Best,

Melba

Re: No Power to Y1 Neat Gen2 Learning Thermostat

MelbaDT — Tue, 21 Jun 2022 03:03:35 GMT

Hey Ricolow,

Checking back in — how's it going with your thermostat now? Still need our help?

Best,

Melba

Re: No Power to Y1 Neat Gen2 Learning Thermostat

MelbaDT — Wed, 22 Jun 2022 03:13:05 GMT

Hi,

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best,

Melba