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Morning All- Hoping to get some guidance/thoughts from folks on this forum. We replaced our old heat pumps with a closed loop geothermal system over the summer with auxiliary heat coils in the event needed for extremely cold days. I'd like to make sure I am running the geothermal system as efficiently as possible to save on $$. I have the system hooked up in two zones running a Nest Thermostat in each zone (2 total).
Couple questions:
I see NEST running in "Stage 2" quite a bit- Is this normal for a geothermal system? When NEST says stage 2, is the thermostat trying to run auxiliary heat? If so, is there any way to change at which temperature "Stage 2" kicks in? Should it be the NEST calling for the Stage 2 heat or should the Honeywell HZ432 be calling for the stage 2 (and determining when it's truly needed)
For those utilizing a NEST thermostat with a geothermal system- Are you setting a schedule with NEST or just keeping at one temperature such that it runs to consistently stay at one temperature?
Including wiring below should anyone notice anything out of the ordinary with the way this was set up. Welcome any thoughts
Appreciate any insight. I recognize electricity costs have gone up, but moving from 2 heat pumps and 2 air handlers to one geothermal system and one air handler with dampers to control the 2 zones, I thought I would see more savings than what I am currently seeing.
Welcome any thoughts. Thanks!

Nest uses algorithms to estimate how long it will take to warm or cool your home to a specific temperature.  When it's colder out I would expect to see Stage 2 more often.  Stage 2 means it running the heat pump at 100%.  I would say it's the NEST controlling the staging and sending the Y2 signal to the Honeywell HZ432.  If you raise the temperature 3.3F above room temperature it should engage Stage 2.  Never use setback schedules in heat pump mode.  Just maintain a constant temperature.  It looks like anything colder the 5F will run the AUX and you should see that displayed on the NEST.  This will also happen when the heat pump is in defrost mode.  I'm not too sure what affect the DATS sensors have on staging or if they interfere with the NEST.

Look up the NEST 10 day history and see how much the AUX is running.

I'm curious as to why second stage or auxiliary heat is on at all being a geothermal system.  Is this indeed a fluid sourced/ground sourced geothermal system? And not a hybrid air source heat pump?  Ground sourced systems should be able to deliver near design heating output constantly, we aren't contending with the changes in temperature of the "outside".  I can't speak for the Nest thermostat, but it can be to do with differential settings on the Nest.  If this is indeed the case, being a honeywell zone board, it would pair very well with a Honeywell Prestige heat pump thermostat. 

Yes, good point.  I read right past geothermal and got focused on heat pumps and AUX heat coils which I assume were electric. 

Did the people who installed the geothermal recommend AUX heat?

Was the NEST and HZ432 installed with the new system or was it part of the original system?

I just noticed under the NEST System Details, it has Electric for Heat Source 1 and 2.  That should be changed to Geothermal under Source Options.  That may remove the AUX heat source and Lockout option and prevent the AUX heat from running.  You may have to disconnect the W1/E wire at the NEST so it doesn't pickup the AUX heat.