Nest blowing hot air on cool

[Threyn]

Nest thermostat blowing hot air.  Ac guy said no problem with wiring.  Used upstairs nest to test if unit was working and experiencing same issue.  Still heating when on cool.  Heat pump.  BElow is my thermo stats wiring.  When I put old stat back on cooling is working. 

Here was my wiring with the nest

Y g o/b w1 c r

i’ve also tried y g o/b c * r

any thoughts

[jina1218]

Same here. Ever since system update yesterday (May 3). Calling AC tomorrow if I can’t find the answer thru Google

[Omar67]

reset your thermostats back to factory settings; go to reset, then go down to all settings, once it resets, it will wipe out everything, you will have to reconnect to the internet and all, but you will be able to reconnect, I had mine in this home for almost 2 yrs, and a few days ago it went haywire, its back up and running, all 4 nest thermostatsback in business

[MelbaDT]

Hey folks, 

Thanks for answering and for your detailed suggestion, Patrick_Caezza. 

Thanks as well Omar67 for sharing what you did to have your concern resolved. 

Threyn and jina1218 , I'm jumping in to check if everything is good here. Have you had the chance to go through Patrick's suggestions above?

Best, 

Melba

[MelbaDT]

Hey folks, 

Checking back in — still need help here?

Best, 

Melba

[Threyn]

Yes I did a factory reset but it didn't work.

[Omar67]

Your thermostat changes over in cooling mode, in the programming it asks do you want to use the O or B terminal, just remember, when you think of orange, you normally think of heat, and when you think of blue, you normally think of cooling, but its the opposite, if you use orange for your reversing valve, your system energizes in cooling and if your system calls for the blue wire, it energizes in the heat mode, I see you are using the blue wire for common, that's ok, just use the orange wire but make sure on the thermostat, you use the B terminal, and outside on your heat pump, make sure your using your orange wire coming from inside, and connect to your blue reversing valve wire outside, I hope I haven't confused you

[Patrick_Caezza]

Your information is wrong.

[Patrick_Caezza]

Looks like you have a simple heat pump with Aux heat system.

This is how you should wire it.

White - E to W2/AUX (jumper to AUX not needed)

Green - G to G

Orange - O/B to OB

Yellow - Y to Y1

Red - R to Rc (jumper to Rc not needed)

You can't just go by the wire colors as there is no standard.

If your system starts to blow cool air when your Nest thermostat is in Heat mode (or if it blows warm air when it's in Cool mode), change the settings for orientation of your heat pump.

Nest Learning Thermostat

1.  On your thermostat, go to Settings.
2. Select Equipment.
3. Select Continue  Continue.
4. Select Heat Pump.
5. The Nest Thermostat defaults to an O setting for heat pumps. 
   • If the O option is highlighted, select B.
   • If the B option is highlighted, select O.
6. To make sure the issue is resolved, test your heating and cooling again.

[Threyn]

I'll give this a try and let you know.

[MelbaDT]

Hey there, 

Got it — keep us posted. We'd want to know the outcome. 

Best, 

Melba

[MelbaDT]

Hey there, 

It's me again — how's it going with your thermostat now? Have you had the chance to try already the suggestions above?

Best, 

Melba

[MelbaDT]

Hi, 

I haven't heard from you in a while so I'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

[Omar67]

if your system is blowing hot air in the cool mode, your  O/B settings are opposite and you should go through your settings, or call out a qualified technician 

[MelbaDT]

Hey Omar67, 

Thanks for your input and you're right. The steps on how to change the orientation of your heat pump was already provided by Patrick above. You might also want to check on this link for more information: https://bit.ly/3o6pPh6

Best, 

Melba

[MelbaDT]

Hi, 

It's me again — since it's been a while since this thread was last updated, we'll be locking it if we won't hear back from you again within a day. Should that happen, feel free to create a new one if you have more questions or have other concerns in the future. 

Best, 

Melba