Thermostat shows incorrect room temperature compared to other thermometers

Steps:

• Compare readings: Place a reliable thermometer near the thermostat and compare readings over 15–20 minutes.
• Check placement: Avoid locations above return ducts, near exterior walls, or where sunlight hits the thermostat.
• Calibration setting: In the Kasa app, look for temperature offset or calibration settings and adjust by the measured difference.
• Insulate back: If wall cavity drafts are suspected, remove the thermostat (power off first) and add a foam gasket or insulation behind the wall plate, keeping wires clear.
• Replace thermostat: If large errors persist even after calibration and placement corrections, the internal sensor is likely defective.