Nest Thermostat blows heat while on Cool setting

[tobifortunate89]

After taking a few hours to get what seems like the correct wire setup, I got the Thermostat to get my a/c unit to blow cold. Upon initial setup, it would only blow heat  The issue now is that while the house is cool, it will then start blowing heat for about 5 minutes before blowing cool again. I've checked my settings to make sure my heat only cuts on at 68°f, but it's coming on at 72-73. I do not appear to have a heat pump. I believe my heat is forced Air only. My o/b setting in the app is set to cool. The top photo is the original thermostat wire placements. Copying that exact placement on the nest thermostat made my unit blow heat only. The bottom photo is the Nest wiring placements that gave me cool air with the little bit of heat in between. Any ideas for fixing the unwanted heat part?

 

 

[Houptee]

You must have a heat pump since you have a OB wire.

Wiring looks correct for a Heat Pump with Aux heat on W.

The black is for Auxiliary electric heat coils that kick on when the outside temperature is too cold for the heat pump to provide heat.  Heat pumps run the outside unit in winter and absorb heat from the air outside but when it gets very cold they cannot keep up and need to use the electric coils to assist.

Did you tell the Nest during setup that is was a Heat Pump forced air system with Aux heat?

If not you need to start over and correct the type of system in the Nest.

If you get the opposite when you ask for heat and get cool or vice versa you have to change the OB setting.

Then you have to set the heat pump balance of how the system uses the electric heat coils.

Read this about how to set the balance once you get the other issue fixed with the heat and cool modes working properly.

https://support.google.com/googlenest/answer/9248719?hl=en#zippy=%2Cauxiliary-aux-heat%2Clearn-more-...

[tobifortunate89]

Thank you for responding. my challenge right now is confirming if I indeed have a heat pump.

 

[CoolingWizard]

That label is for the HEIL Indoor air handler. Can you post a picture of the outdoor units label? The blower unit does not have a control board that is heat pump aware.  If you have a heat pump the thermostat cable Orange conductor will be cross connected to a wire in a cable going to the outdoor unit Control Board and attached to the O terminal. I strongly believe you have an R22 refrigerant based heat pump. You thermostat wires being used are R, Y, G, O/B, and E.

Ken, The AC Cooling Wizard

[EdwardT]

Hi folks,

@CoolingWizard and Houptee, thanks for the help!

@tobifortunate89, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward

[aatienza]

Hey there,

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have. 
 

Thanks,

Archie

[tobifortunate89]

Hey everyone. Thank you all so much. I tweaked the wiring and settings a little more based on recommendations and got it working. You're all fantastic and your response times were helpful.

[aatienza]

Hey tobifortunate89,

Awesome! Let us know if you have other questions as I'll be locking the thread after 24 hours.

Thanks,

Archie