Thermostat displays E06 and shows incorrect room temperature (far off from actual) or fluctuating rapidly.

Safety first: Turn off power to the HVAC system at the breaker before removing the thermostat from the wall plate.

• Step 1 – Compare temperatures: Place a reliable digital thermometer near the thermostat and compare readings. If the Geo reading is off by more than 3–4°F, a sensor or placement issue is likely.
• Step 2 – Check for external heat sources: Ensure the thermostat is not above a supply duct, in direct sunlight, or above electronics that generate heat. If warm air leaks from the wall opening, seal the hole behind the wall plate with foam or putty.
• Step 3 – Reboot and recalibrate: Remove the thermostat from the wall plate for 30 seconds, then reattach. In the settings menu, look for Temperature Offset or Calibration and adjust by a few degrees to match the reference thermometer.
• Step 4 – Inspect sensor area: With the thermostat removed, visually inspect the PCB for damage near the small thermistor bead or sensor area. Ensure no dust or debris is packed around the sensor vents.
• Step 5 – Factory reset: If the error persists, perform a factory reset from the settings menu (note this will erase schedules and Wi‑Fi settings). Reconfigure and recheck the reading.
• Step 6 – Replace thermostat: If E06 remains and readings are still inaccurate, the internal sensor or its circuit is defective. Replace the thermostat head unit.