where's the best place to put the ecobee smart sensors? i put one in my living room and it doesn't seem to notice when i'm home.

Diagnosis

The issue isn't necessarily the sensor's hardware, but rather a "blind spot" in the occupancy detection field. The ecobee SmartSensor uses a Passive Infrared (PIR) sensor to detect heat signatures moving across its field of view. If the sensor is placed behind a curtain, tucked behind a sofa, or positioned in a corner where you only walk *away* from it rather than *across* it, the PIR sensor will fail to trigger the "Occupied" status. Furthermore, the sensor must have a clear line of sight to the areas where you spend the most time. If the sensor is placed too high (above 7 feet) or too low (under 3 feet), the detection angle becomes skewed, and the device may ignore subtle movements. This leads to the thermostat reverting to its "Unoccupied" profile, which often lowers the target temperature to save energy, making you feel like the system isn't noticing your presence.

How to Fix It

To optimize the occupancy detection and temperature accuracy of your SmartSensor, follow these precise placement and configuration steps:

1. Identify the "Traffic Path": Place the sensor on a wall where you are most likely to cross its path. PIR sensors are most sensitive to movement *perpendicular* to the sensor. Do not place it directly facing a door where you walk straight toward it; instead, place it on a side wall so you walk across its field of vision.
2. Optimize Height: Mount the sensor between 3 and 5 feet from the floor. This is the "sweet spot" for detecting human body heat signatures. Avoid placing it near the ceiling or on a low coffee table.
3. Avoid Thermal Interference: Ensure the sensor is at least 5 feet away from heat-generating appliances. This includes lamps, televisions, gaming consoles, or direct sunlight from windows. If the sensor detects a heat source, it may report a falsely high temperature, causing the AC to run constantly or the heat to never kick in.
4. Verify Connection: Open the ecobee app, go to Main Menu > Sensors, and select the specific sensor. Check the signal strength. If it shows "Poor," move the sensor closer to the main thermostat or a SmartTherm Premium hub to ensure the occupancy signal is transmitting without latency.
5. Configure Participation: In the app, go to Comfort Settings. Ensure the sensor is assigned to the correct "Comfort Setting" (e.g., Home, Sleep, Away). If the sensor is not checked for the current active profile, the thermostat will ignore its occupancy data entirely.

If That Didn't Work

• Test the "Follow Me" Feature: Enable "Follow Me" in the device settings. This tells the ecobee to ignore the main thermostat's temperature and instead average the temperature of only the sensors currently detecting motion. If the system starts responding immediately after this, your previous issue was a configuration conflict between the main unit and the sensor.
• Check for Signal Blockage: If you have thick plaster walls or metal studs, the 900MHz signal may be attenuated. Try moving the sensor to a different wall in the same room, specifically one with a more direct line of sight to the main thermostat unit.
• Perform a Hard Reset: Remove the batteries from the sensor for 60 seconds and re-insert them. This forces the sensor to re-sync its occupancy heartbeat with the main hub, clearing any cached "unoccupied" states that may be lingering.
• Adjust the "Occupancy Timeout": If the sensor notices you but "forgets" you too quickly, check your home/away schedules. Ensure your "Home" window is wide enough to account for periods of stillness (like watching a movie), as the PIR sensor requires movement to maintain the "Occupied" status.

Heads Up

• Battery Life: Use high-quality Lithium AAA batteries. Alkaline batteries can leak or drop voltage quickly, which often manifests as intermittent occupancy detection before the sensor actually dies.
• Avoid "Dead Zones": Never place a sensor behind a door or inside a bookshelf. Even a thin piece of fabric or a plastic decorative item can block the PIR lens, rendering the occupancy sensor useless.
• Calibration Lag: When moving a sensor to a new location, allow it 24 hours to calibrate to the new ambient temperature of that specific wall before judging its accuracy.