Installed Nest Learning Thermostat gen3 on cool mode only heat blows.

[Giszmo69]

Installed Gen3 Nest Learning Thermostat when in cool mode only heat blows out. Put back original thermostat and HVAC works fine. Below is Honeywell wiring.

Nest Thermostat wiring configured as Blue on C, Red on Rc, Orange on W1, Yellow on Y, Green on G, and White on W2.

What did I do wrong? How do I wire my Nest Thermostat correctly?

[jb76]

Hi - your Nest setup looks correct from what you described to match the original Honeywell connections. To confirm that Y is controlling the AC/Compressor, turn off the power to your furnace/AC and disconnect the Nest thermostat from its base. Wire the Rh and Yellow wires connected to the base together (twist them together). Flip the breaker/power back to furnace and confirm the AC/Cool air turns on. If cool air comes through, then the wiring is correct and you will need to check the wiring setup in the Nest configuration.

To confirm this setup on the Nest, disconnect power to furnace, reattach the Rh and Y wires back to the Nest backplate. Reconnect the Nest thermostat to the backplate and restore power to furnace/Nest.

Open the Nest Settings menu and select Equipment -->please reply with what the Nest detected for your equipment.  You will likely need to follow these steps if you have a heat pump to switch heat vs. cold:

https://www.googlenestcommunity.com/t5/Nest-Thermostats/O-B-heat-pump-settings-reset-can-t-see-equip...

Can you also confirm that the Nest is getting enough charge to the thermostat (bring up Nest app, select thermostat --> Settings icon-->Technical Info. - should read 3.85 V or higher?

J

[Giszmo69]

Thank you for the reply.

With the Nest Thermostat wiring configured as Blue on C, Red on Rc, Orange on W1, Yellow on Y, Green on G, and White on W2. Equipment detected was gas furnace 1 and gas furnace 2. I do not have a gas furnace. Nothing regarding A/C or heat pump.

Should the Nest Thermostat wiring configured as Blue on C, Red on Rc, Orange on O/B, Yellow on Y, Green on G, and White on W1.

Charge on Nest Thermostat is currently 3.795V.

Any of this wiring testing damage my HVAC?

[jb76]

Hi - none of this configuration/testing will interfere/break your HVAC. 3.79 V is a low value for power going to the Nest - this should be at least 3.85 V to operate your HVAC/connect on wifi. If you have a heat pump, yes, wiring should be:
Blue on C, Red on Rc, Orange on O/B, Yellow on Y, Green on G, and White on W1

As described here:
https://www.googlenestcommunity.com/t5/Nest-Thermostats/O-B-heat-pump-settings-reset-can-t-see-equip...

Your issue seems to match the behavior associated with a heat pump and an issue with cold blowing hot and hot blowing cold. Please charge your Nest thermostat for an hour using a microUSB and reattach to get into the Settings-->Equipment and configure it to control a heat pump:

•  On your thermostat, go to Settings.
• Select Equipment.
• Select Continue > Continue.
• Select Heat Pump.

J

[Giszmo69]

Thank you jb76. I will give this configuration a shot.

[zoeuvre]

Hi folks,

@Giszmo69, thanks for posting here, and I'm sorry to hear that your recently installed Nest Learning Thermostat blows heat when in cool modI want to check if you already managed to follow the configuration from jb76. Please let us know if you still have questions or concerns, as we'll be willing to assist you more. 

Thanks for your help, @jb76. 

Best,

Zoe