Dual fuel mirror nest not heating with new heatpump

[Christmasflag]

Had a gree flexx heat pump installed in July.  It cooled fine. We have a gas furnace as alternate. When switching to heat mode nothing happened. Tried messing with settings and started over. Tried both o and b option and only cool air comes through vents. Currently using alternate heat source all the time.

[zoeuvre]

Hi Christmasflag, 

Thanks for posting here in the Community forum, and I'm sorry to hear about the situation. I want to check if you are still in need of any help. If so, please answer the following:

1. Are you located in North America or Europe? 
2. Does the thermostat screen indicate that it’s actively calling for heating?
3. What type of heat pump system do you have? (gas, electric, etc.)
4. When did heating last work?
5. Did heating ever work with the Nest Thermostat?
6. Did you turn off the power to the HVAC system?
   • Did you recently turn off any breakers?
   • Have you recently experienced a brownout or blackout?
   • Is there a light switch near the heater that controls an outlet?
7. Did you select the correct fuel type?
8. When was the last time you changed the furnace's air filter?

Also, gather the power readings of your Nest Learning Thermostat's Battery, VOC, VIN, and lIN under Settings > Technical Info > Power. 

Keep us posted. We're happy to help.

Best,

Zoe