Nest Thermostat not heating with Rheem R-410A Heat Pump

[Acris]

System cools just fine but does not heat.  In heat mode thermostat indicated heat mode, fan comes on, but heat pump compressor does not come on.  

I have images that show the original thermostat wiring config and the Nest wiring config, but Google Nest community message "you do not have permission to upload images".  So, thermostat seems to be correctly wired.  Could this be a configuration problem?

[Acris]

[Derickf]

Hi @Acris,

Thanks for posting in the community. I was looking at the pictures you provided, and it seems that your HVAC system is not compatible with the Nest thermostat you have due to the Nest thermostat only having 6 terminals, and the previous wiring configuration had an extra wired twist to the white wire on the w2 terminal, and the Nest Thermostat doesn’t work with that kind of wiring. 

Please keep me posted if you have any other questions.

Best regards,

Derick.

[Acris]

Thank you!

[Acris]

From what you observed in the pictures I posted, do I need a 3rd or 4th Generation thermostat?

[Derickf]

Hey there!

Thank you for your reply. Based on the system you have I recommend any of the Learning thermostat ( 3rd or 4th), but before you get one of those it is important to re-wire the system because it seems that the w2 terminal works with 2 wires at the same time that's the reason the Nest Thermostat you currently have is not working properly, and it is not recommended to install another thermostat unless the system is re-wire to be completely compatible with the Nest Thermostats. 

I'll be looking for your reply,

Best regards,

Derick.