05-25-2022 09:03 PM
The top picture is my older thermostat and the second picture is my attempt at installing my nest thermostat.
During set up it is saying that my W and Y are not connected and I cannot for the life of me find any info online about a set up where both the w and y use the white wire like my older thermostat does.
Hoping someone can point me in the right direction.
05-25-2022 09:19 PM - edited 05-25-2022 09:19 PM
The device that the W and Y are coming out of is a special interface used by the old thermostat. It uses a single wire (white) to activate W for heat and Y for cooling. You will need a HVAC technician that is also a NestPro to make some changes. You will need a No C-Wire adapter and the HVAC technician will need to rewire the HVAC system to use the white wire for Heat and the Black wire for Y cooling. Then the No-C Wire adapter will then bring C to the thermostat.
05-25-2022 10:14 PM
So theoretically, would running a new 5 conductor thermostat wire also do the trick?
05-25-2022 09:20 PM
That little adapter with the Y and W on it is not compatible with any Nest Thermostat.
If you look in the furnace/air handler I'm sure you will find another adapter connected to the white wire and the system.
It looks to be similar to the Add-A-Wire device that you can use to create a C wire. YOu can replace it with the Nest Power Connector which does the same thing but for Nest.
05-25-2022 10:15 PM
So theoretically, would running a new 5 conductor thermostat wire also do the trick?
05-27-2022 03:08 PM
Yes, replacing the existing cable with a 5-wire cable will eliminate the need for the Power Connector
06-09-2022 12:08 AM
Hey folks,
Thanks for taking care of this, Patrick_Caezza and CoolingWizard.
Dwardo89, I hope you've got the answer you're looking for. Let us know if you have further questions in mind.
Best,
Melba
06-13-2022 08:29 PM
Hey Dwardo89,
Checking back in should you have more questions about this. Let us know by replying to this thread.
Best,
Melba
06-14-2022 09:03 PM
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
05-25-2022 10:24 PM - edited 05-26-2022 06:02 AM
If you can run a new thermostat wire between the thermostat location and the HVAC air handler it would help. If considering that the special splitter was used, I doubt it will be easy. You need to have a good understanding of how the system works. Here is a bit of a primer. The R wire brings 24 Volts AC to the thermostat. The G terminal controls the Blower Fan. The W terminal is used to call for a heat and the Y terminal is used to call for Cooling. If there is a heat pump outside, it will use a O/B wire. Lastly, the C terminal is for the Common or return path of the 24VAC. The thermostat connects R to G to turn in the blower fan, R to Y to turn on the AC compressor and the R to W to initiate Heating. Now if you have a heat pump, the R will be connected or the O/B. Some heat pumps default to cooling and some default to heating. Simply put, R to O/B changes a heat pump form Heat to Cool or Cool to Heat.