DIAGNOSIS The thermostat's internal temperature sensor is being influenced by a local heat source or is out of calibration.
FIX Relocate the thermostat. Ensure it is not in direct sunlight, placed over an active heat register, on an exterior wall with poor insulation, or near appliances like televisions or lamps that generate heat. The ideal location is an interior wall, approximately 5 feet off the floor.
IF THAT DIDN'T WORK Check for firmware updates in the app, as updates can include sensor calibration improvements. As a diagnostic, place a known-accurate thermometer next to the thermostat for one hour. If the discrepancy is consistent and greater than 3°F, the sensor may be faulty.
HEADS UP The Sensi Touch does not have a user-accessible calibration offset. If the sensor is faulty and relocation doesn't help, the unit will require service or replacement.