I purchased and installed two 4th-gen Nest Learning Thermostats. One is working correctly, but the other is always off by about five degrees, running hotter than I want. I set the thermostat to 70° and used an independent, accurate thermometer that reads 75°. I am also using the sensors that came with the thermostats, one per device, placed in an area away from exterior walls, windows, or drafts. They are also approximately at the same height as the thermostats.
When I select the hallway thermostat that has the issue, I see the following:
Mode: Heat
Sensors: Hallway Thermostat (this thermostat) and Kitchen sensor are selected.
Hold: not used
Fan: not used
Indoor Temperature: 72°
Indoor Humidity: 54%
Outdoor Temperature: 52°
Schedule: Using Heat Only (sensors = this thermostat and kitchen sensor)
Week AM: 70˚ heat, 73˚ cooling, sensors 2, all week, 4:30 am
Week Late AM: 70˚ heat, 73˚ cooling, sensors 2, all week, 7:00 am
Week PM: 62˚ heat, 73˚ cooling, sensors 2, all week, 6:30 PM
Sleep: 62˚ heat, 73˚ cooling, sensors 2, all week, 11:00 PM
Energy Dashboard: seems ok
Nest Sense:
Smart Schedule: Off
Energy Shift: Not used at this time
Seasonal Savings: Inactive
Natural Heating and Cooling: On Enable Natural Heating & Cooling: On. Window Reminders: Off
Adaptive Comfort and ECO: Off
Early-On: Heating, On (1-hour), and cooling off at this time
Airwave: on (used only for cooling)
Humidity Helper: Off
True Radiant: Off
Sunblock: On
Temperature Presets:
All looks ok
Safety Temp: Heat 40˚ Cooling Off
The other settings don’t matter right now.
After noticing the 5-degree delta, I tried a few things:
I removed the kitchen sensor from the equation and noticed that the thermostat's temperature sensor reading was 72˚ and the heat setting was 70˚. I also saw that the kitchen started to cool down. The independent thermometer dropped from 75˚ to 72˚ over a few hours. The thermostat was set to 70˚, and its internal sensor was showing 71˚.
So the sensor may be the problem, but why a 5˚ delta?
How are others using or not using their sensors?
Has anyone else experienced this problem? Maybe someone from Google can chime in to help.
Thanks
