Nest not blowing cold Air

[ShadoVv]

Hello all at 1st I was getting only hot air on cool. I switched some wires, and the heat pump setting now I am getting air but it is not cold. any ideas what could be the issue ?

 

[Patrick_Caezza]

Post a picture of the original thermostat's wiring

[MelbaDT]

Hey folks, 

Thanks for your response here, Patrick_Caezza. 

ShadoVv, how's it going? Still need our help here? If you do, please provide the requested photo above so we could keep the ball rolling. 

Best, 

Melba

[MelbaDT]

Hey ShadoVv,

Checking back in should you still need help with your Nest thermostat. Let us know by replying to this thread. 

Best, 

Melba

[ShadoVv]

Hello all thanks for the response,

I could not find the Picture with my older thermostat setup, before the wires were removed But I did keep the old unit as I made the change some time last year Fall.
I did get in contact with a Nest Support Agent, and I was told it might be an issue with my Yellow wire, I am working on getting that looked at as soon a possible.

But before I do, I realized on my old Thermostat the RH and RC looks like there were connected together with the black wire bridged, would doing the same on the Nest possibly be my solution ?

See Attachment below.

[Patrick_Caezza]

The jumper is not needed as the Nest will do it for you.

Are there any spare wires?

Take a look at the terminal block on the control board in the furnace/air handler and post a picture of it here.

[ShadoVv]

Good Day all here is the a picture of the control Board in the handler.

[Patrick_Caezza]

You have a conventional system and not a heat pump.

Your wiring looks correct going by that picture.

Do you have a Humidifier installed?

I see a spare blue wire, you should connect that to the C terminal and then the C terminal on the thermostat. Then do a reset to factory defaults and set it up again.

[ShadoVv]

Hello Patrick

I do have a Humidifier, I tried as you suggested and got the blue wire connected and on the Handler and Thermostat and reset the Thermostat to Default but now I am not detecting the Heat, only Fan and Cool, and I am still getting Warm air on cool and the Blue C wire is being detected.

Also while looking I found a Pic of the Old thermostat, connections, I will try to reinstall the old Tstat to see if I may have an issue else where today after work.Blue C Wire ConnectedOld Tstat connected

[Patrick_Caezza]

I'm seeing that you used a second white wire and marked it with some blue ink. Did the blue wire not go to the thermostat?

Are you 100% sure you didn't mix up the white wires at the thermostat?

Give this a try, Connect the Yellow, Green, and Red wires together and it should blow cool air. If it doesn't then something is wrong with your system. If it does, then your thermostat might have a problem.

Do the same with the White, Green, and Red wires and it shouldblow heat this time.

Be sure to turn your system off before moving any wires.

[MelbaDT]

Hey folks, 

Appreciate your help and your suggestions, Patrick_Caezza. 

ShadoVv, I'm jumping in to ensure you've seen Patrick's last response above. Have you had the chance to try his suggestions?

Best, 

Melba

[ShadoVv · Accepted solution]

• Hello Patrick thank you for the response, I did add the white wire as some on cut the blue wire very short behind the Tsat, so I tried what you said still a no go. So I called a local Hvac shop. And the issue was my System Comprosser, that then blew the red connecting wire off as well. This was a great learning experience, Thank you every one for the help we have cool Air.

[MelbaDT]

Hey ShadoVv, 

You're welcome — thanks also for getting back to us and for keeping us in the loop of what had resolved your concern. We're glad to hear that you've got cold air now and a thermostat that is working  as it should. Should anything comes up, feel free to let us know. 

Cheers, 

Melba

[MelbaDT]

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