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NO COOLING FUNCTION?

Frost462
Community Member

I have a 4 wire HVAC system with a jumper from RH to RC and have connected the wires from the old layout to the Nest accordingly, but there is no cooling function on the Nest once done.   I've attached a photo here -> {--}, but realize the bottom row letters are not visible.  For your guidance, the first slot is C, then G, then the next is skipped, then Y (which is the blue wire).  Anyone have a clue why the cooling option is not available?  I just bought this old house (1954) and am not super savvy so go easy, please.   

 

 

19 REPLIES 19

Houptee
Silver Product Expert
Silver Product Expert

Only connect red wire to Rc do not use any jumper wires on the nest.

Then match up the other wires.

You should see the wiring change is detected when you reinstall the nest.

The other issue is you should have a C wire connected if possible. So if you have a spare wire color in the cable coming out of the wall you can connect it to the C terminal at the furnace and also on the nest. If you pull the wire out of the wall see if there is a extra wire not being used.


Houptee -- NJ Master HVAC Licensed Contractor

Frost462
Community Member

Thanks for the info.  I was wondering if I needed a C-wire...  I'll pull the wires out further and check, but I don't think I have one.  I assume then, that purchasing the adapter would be sufficient?

CoolingWizard
Platinum Product Expert
Platinum Product Expert

Since you have no available conductor for the [C]ommon, you will need a Nest Power Adapter. If you have a Nest Learning Thermostat 3rd Gen, it can in some cases, reach the Common using the Y or W wire.  What type of heating system do you have?

Ken, The AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

I have a gas furnace. 

CoolingWizard
Platinum Product Expert
Platinum Product Expert

Things look good then.  Using the Google Nest configuration tool when you install, you will identify Rc, Y, G, W wires. Rc is red wire, Y is blue wire, G is green wire, and W is white wire. 

Ken, The AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

Frost462
Community Member

Thank you for the assistance!  I have ordered the connector and will try it out as soon as possible.

Jenelyn_O
Community Specialist
Community Specialist

Hi there,

 

Thanks for reaching out. I just want to confirm if you already installed your Nest Power Connector? If you have any questions or concerns, please let us know. 

 

I appreciate your help, @Houptee, and @CoolingWizard.

 

Best,

Jenelyn

Frost462
Community Member

Good afternoon,

The adapter should arrive today, and I will attempt to install it tonight if I get home at a decent time.  I will advise once I do, whether it solved my problem or not.  I appreciate everyone's assistance 🙂

Jenelyn_O
Community Specialist
Community Specialist

Hey Frost462,

 

Thanks for the update! You can visit this support article for more information to install a Nest Power Connector and on how it works. 

 

Regards,

Jenelyn

Jenelyn_O
Community Specialist
Community Specialist

Hi Frost462,

 

I wanted to follow up if you still need help. Please let me know if you’re still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

 

Thanks,

Jenelyn

Good afternoon. Still no cooling function. I assume I connected it correctly, but please advise? Before & After photos 

IMG_20230319_170823.jpg

IMG_20230319_170835.jpg

Jenelyn_O
Community Specialist
Community Specialist

Hi Frost462,

Thanks for the update. I'm sorry for the delay. Do you see any messages or code on your Nest Thermostat? You can check it by going to your thermostat Settings then look for Equipment. After that, gather your thermostat power readings, just go to Settings, then Technical Info and Power. 

Best,
Jenelyn

CoolingWizard
Platinum Product Expert
Platinum Product Expert

Frost462,

The problem is you personally incorrectly wired the power connector and that is why  your cooling did not work correctly. You wired the power connector W*Y wire to the Y terminal of the White-Rogers control board and your Air Conditioning Condenser unit wire was removed from the control board.

That two wire cable with the white wire, and the red wire, in which the white wire was connected with the blue wire to the Y terminal on the White-Rogers control board.

it looks like you moved the blue wire to the connector of the power connector, and you moved the white wire and that was your mistake.  That white wire needed to stay on the Y terminal on the White-Rogers control board along with the W*Y wire coming from the power connector.

Additionally, at the end by the White-Rogers control board there is a cut off yellow wire. That means there should be a yellow wire at the end behind your thermostat.

The AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

Hello there,

 

I wanted to ensure that everything was covered here.

 

Thanks for the continued support, @CoolingWizard.

 

@Frost462, I wanted to see if you still needed help. Please let us know if you have any other questions or concerns.

Regards,

Mark

Hi Frost462,

 

I'm checking back in — how's it going? Still need our help?

Thanks,

Mark

Hello Frost462,

 

It has been a few days since your last reply, and we're going to lock the thread within 24 hours. If you have any questions, please feel free to create a new post.

Thanks,

Mark

Frost462
Community Member

I have returned the Nest and the adapter and purchased a non-smart thermostat in its place. 

Jenelyn_O
Community Specialist
Community Specialist

Hi there,


 

We're sad to see you go, Frost462. We hope we can make it up to you in the future. Please feel free to message us if you need help. Otherwise, I'll be locking this thread after 24 hours. 


 

Best,

Jenelyn