Nest thermostat not heating.

[Pastorsteve33]

I have read all the posts that I can.  I have installed nest thermostat at my church,.  I replaced a a 6 wire carrier thermostat.  The heat pump can be heard turning on, but no heat comes out even with hours running.  Temps have been in the high 30's up to 60 durning the day.  I have tried to switch from O to B and there was no difference.  I can turn on the emergency heat and it works perfectly.  Im sure this is a wiring issue, but I have matched the carrier set up exactly to the 6 wire nest.  Any help would be appreciated

[Markjosephp]

Hello Pastorsteve33,

Thanks for putting a lot of effort into installing the Nest Thermostat at your church, and based on your description, it does seem like a wiring-related problem. Let's sort this out!

Firstly, great job on checking the O/B switch; that's a common culprit in heat pump installations. Since emergency heat is working fine, it suggests the issue may be with the regular heat pump operation. Double-checking the wiring is crucial. Even if it seems like you've matched everything, a small oversight could lead to these problems. Ensure that each wire is securely connected to the corresponding terminal on the Nest Thermostat. Sometimes, labels on wires can be misleading, so it's helpful to confirm the function of each wire.

If everything seems in order with the wiring, it might be beneficial to try running the cooling as well. If the issue persists, try performing a factory data reset to bring it back to its default settings, and make sure to configure the wires exactly the same in the Google Home app.

I hope this helps, and let us know if you need more assistance.

Best regards,
Mark