Need a new base (unit gets stuck commanding aux heat)

[Rat4go]

My thermostat (or base) has developed an issue where if the aux heat (heat pump) is commanded on, it will stay commanded on, even when the set temp is reached and will continue heating. I've isolated the issue to the thermostat base. Removing the thermostat from the base does not resolve the problem, however, disconnecting the aux heat wire from the base DOES solve the problem. I also borrowed a base from someone and confirmed that the issue went away. I also reinstalled the previous (non-nest) thermostat and the issue was no longer present. I firmly believe I need a new base but can not seem to find a NEW one. Used ones are available on ebay but I don't want to risk buying one with the same (or another) problem. Where can I source a new base?

[Rusell]

Hi Rat4go.

Thank you for posting in the community, I understand that the auxiliary heat is not turning on. I'm happy to help!

I'd like to ask a few questions about your concern about this as:

• What type of thermostat do you have?
  
• Are you able to post a photo of the correct wiring configuration? 
• What HVAC system do you have?
  

In the meantime, if you have any further questions, please don’t hesitate to reply to this post. I'll be happy to assist you further!

Best regards,

Rusell.

[Rat4go]

Nest Gen3 Learning thermostat.

Heating system is a heat pump with electric supplemental heat.

I'll try to upload a photo later... but when I borrow a base from a friend with the same model, it works fine. I'm 99.99% sure the base has an internal issue.

[Rusell]

Hi Rat4go.

Thank you for response and the information provided but for this type of inconvenience, it'd be nice if you Contact Us - Google Nest Help by phone to provide you the correct wiring steps and please share the photo with them. 

Please don't hesitate to reply to this post, If you have any further questions. I'll be happy to assist you further!

Best regards,

Rusell.