topic Re: Heating when in cooling mode in Nest Thermostats

Heating when in cooling mode

maucp — Tue, 25 Feb 2025 21:09:28 GMT

I installed my Nest 3 weeks ago, and heating was fine, but today I've tried many attempts, and when I switch to cooling mode, it sends heat through the vents, which led me to this forum. Maybe someone can take a look at the previous wired controller and spot the mistake.

maybe @Patrick_Caezza can help me hehe i saw a similar post with your name there bud

images below

https://postimg.cc/gallery/L2HN3yL

Re: Heating when in cooling mode

GabrielaG — Thu, 27 Feb 2025 18:45:39 GMT

Hi @maucp,

Thanks for reaching out to the Google Nest community. I'm sorry to hear your Nest Learning Thermostat is blowing warm air instead of cool, but there's no need to worry; I'm happy to help you right now.

I appreciate the pictures you provided me with the wiring of your Nest Learning Thermostat. To get a better understanding of the situation, please help me out by answering the following questions:

Just to confirm, is your HVAC system a Heat Pump?
Do you have error codes in the screen of the Nest Thermostat?
What other strange symptoms have you experienced since the problem started?
Did you recently experience a brownout or blackout?
Have you done troubleshooting steps? If so, can you list them?

Any additional details you can provide will be helpful.

Regards,

Gabriela

Re: Heating when in cooling mode

maucp — Thu, 27 Feb 2025 19:45:15 GMT

hi tnx for the answer,

Just to confirm, is your HVAC system a Heat Pump? i live in an apartment complex i have no access to the main unit to confirm it 100% but from what iv asked the maintenance guys i does have an orange cable for the reverse valve, so im pretty sure i do have a heating pump but not 100 % ill try to get a pic of the sticker on the main unit
Do you have error codes in the screen of the Nest Thermostat? nope
What other strange symptoms have you experienced since the problem started? none, i haven test the nest a lot because of the weather , so when it was cold it worked like a charm, but now that i need to run the AC the problem appear
Did you recently experience a brownout or blackout? nope
Have you done troubleshooting steps? If so, can you list them? yes, i even re install the main thermostat and all works perfect with that one , also re install and factory settings on the nest and re do all the first steps but nothing works.

Any additional details you can provide will be helpful.

Re: Heating when in cooling mode

GabrielaG — Thu, 27 Feb 2025 22:34:14 GMT

Hi @maucp,

Thank you for your reply. I appreciate the time you took to answer my questions and provide all this important information. I'm happy to continue assisting you.

I recommend performing some steps to check if there's a problem with the backplate of your Nest Learning Thermostat. If you are comfortable troubleshooting the wiring on your Nest Thermostat, please follow the steps below:

Please turn off the breakers of your air conditioning.
Check the air filters. If the air filter seems dirty or there seems to be a clog, you need to replace the filter.
Check the O/B wire configuration and try changing the O-wire to the B-wire configuration or vice versa.
Swap O/B and G wires on the Nest terminals, then test for cooling and heating.
Verify if the Fan and Heating still work.
Swap Y1 and G wire, then call for cooling.
Verify if the Fan and Cooling still work.
Return all the wires to the original position, and then please factory reset your Nest Thermostat to set it back in the app.

Let me know how it goes.

Regards,

Gabriela

Re: Heating when in cooling mode

Patrick_Caezza — Sun, 02 Mar 2025 03:45:13 GMT

@maucp

Sorry for the delay in responding.

I would make a couple of changes to how you wired the Nest.

Red - RH to Rc (jumper not needed)

White - W2 to W2 (set as AUX heat)

Green - G to G

Yellow - Y to Y1

Orange - O to OB

Blue - C to C

I see that you are in an apartment. Is there a furnace/air handler closet there? If there is, take a look inside of it and see if you can check how the thermostat cable is terminated inside of the unit.

Re: Heating when in cooling mode

maucp — Mon, 03 Mar 2025 00:35:31 GMT

hey @Patrick_Caezza , tnx for the help

so iv done all the setup from zero, and didn't have luck still all heat, im going to add a bunch of pics of the process in order maybe you guys can spot something im doing wrong or an alternative setting it up, also gonna add pics of the closet if you like me to open something and take more pics just let me know , not a pro but im an engineer so i don't mind messing up with stuff just point me in the right direction .

Re: Heating when in cooling mode

GabrielaG — Mon, 03 Mar 2025 00:48:39 GMT

Hi @maucp,

Thank you for your reply. I'm glad to hear that your Nest Learning Thermostat is working now. I appreciate your effort doing troubleshooting steps to resolve this problem.

Feel free to keep us posted if you have more questions.

Best regards,

Gabriela

Re: Heating when in cooling mode

maucp — Mon, 03 Mar 2025 00:55:57 GMT

i think you miss read something, but as i stated on last post , no luck all heat , but tnx for been here checking and helping 😋

Re: Heating when in cooling mode

maucp — Wed, 05 Mar 2025 23:20:44 GMT

@Patrick_Caezza

hope you can give a look to my past reply maybe you can spot something wrong with my config tyvm in advance

Re: Heating when in cooling mode

Patrick_Caezza — Fri, 07 Mar 2025 00:49:23 GMT

@maucp

Looking at the schematics you include makes me wonder if you even have a heat pump.

Can you post a picture of the thermostat cable wiring in the furnace/air handler?

Re: Heating when in cooling mode

maucp — Tue, 11 Mar 2025 18:01:08 GMT

hi, so after been kinda frustrated with the learning nest, a friend lend me his normal nest thermostat , i installed it the same way i was installing the other one and it works perfect no problems at all it does change from cold to hot and no issues , what was the main problem i haven't figured out yet , but ill keep testing and maybe get another learning thermostat and try it out at home to see if it was a faulty thermostat or maybe not compatible , ill keep posting here after i do some tests