I don't have any experience with geo systems, but I tried a Nest with my conventional gas/electric system, and I didn't like it. See my comparative review of the Nest vs. the Honeywell RTH9580 "Smart Thermostat".
How about this:
I wouldn't use a NEST for any system, period.
The NEST is an over hyped DOG of a thermostat.
Scratch that. I love dogs! It's a piece of crap.
What lies behind us and what lies before us are small matters compared to what lies within us.
Two pressures, four temperatures = SUCCESS!
Boulder Heating Contractor
For HVACR Professionals:
Beside for geothermal is the nest T-stat any good o heard it nothing fancy just looks
Its garbage IMO.
Originally Posted by ThaddeusM
Did Nest ever put an emergency heat setting on their control?
Here is some info from the nest website in regards to the emergency heat question:
What’s Emergency Heat and does Nest support it?
Some heat pump systems include a feature called Emergency Heat, which is a heat source typically activated by a manual switch or button on the thermostat and can be used if the primary heating system isn’t functioning. Learn more about how the 2nd generation Nest Learning Thermostat controls Emergency Heat below.
Other thermostats that have a connector labeled E typically will also have a switch or a button on the thermostat labeled Emergency. When this switch is turned on, the emergency heat source will remain turned on and will stay on until you manually turn it off.
Most thermostats will run Emergency Heat constantly until you manually turn it off. With Nest, you can set a heating setpoint for your Emergency Heat and Nest will turn Emergency Heat on and off automatically to maintain the temperature you’ve set. Nest does not support schedules for Emergency Heat.
You’ll need to connect your Emergency Heating wire to Nest’s connector and let Nest know you’ve installed an Emergency Heat source there during setup.
Important Note: The 2nd generation Nest Learning Thermostat doesn’t support using your 2nd stage or auxiliary heat source as emergency heat. If your old thermostat has a short jumper wire from the AUX or W2 connector to the connector labelled E, just remove the jumper and Nest will engage the 2nd stage heating when its needed to keep your home warm.
Once your Nest is configured to control your Emergency heat, here’s how to turn it on:
Select SETTINGS from the main menu
Select EMER. HEAT
Confirm that you’d like to turn on Emergency Heat
Select a heating setpoint
Running Emergency Heat is usually expensive and inefficient. We recommend you contact an HVAC technician for a system check up if you need to run Emergency Heat to keep your home warm.
To turn off Emergency heat, press the ring and select the orange and blue dots from the Nest menu to enable heating or cooling mode.