the room sensor for my ecobee enhanced says 'unoccupied' even when i'm sitting right in front of it.

Diagnosis

The Ecobee Smart Thermostat Enhanced room sensors utilize Passive Infrared (PIR) technology. Unlike a camera or a microwave radar, PIR sensors do not "see" people; instead, they detect changes in infrared radiation (heat) moving across their field of view. If you are sitting perfectly still, typing on a laptop, or reading a book, the sensor may not detect enough thermal variance to trigger an "Occupied" state. This is a deliberate design choice to prevent the HVAC system from cycling constantly due to minor movements like a ceiling fan or a curtain fluttering. Furthermore, the "unoccupied" status is often a result of the sensor's specific detection arc. The sensor has a wide horizontal field of view but a narrower vertical one. If the sensor is mounted too high on a wall or placed too low on a side table, your heat signature may fall outside the active detection zone. To confirm if the sensor is actually malfunctioning or simply not triggered, stand approximately 5 feet in front of the sensor and wave your arm briskly from side to side. If the status changes to "Occupied" within 30-60 seconds on the main thermostat display, the hardware is functioning correctly, and the issue is related to placement or movement thresholds.

How to Fix It

To ensure your room sensor accurately detects your presence and contributes to the "Follow Me" feature, follow these precise optimization steps:

1. Relocate for Line-of-Sight: Move the sensor to a location where it has an unobstructed view of the primary seating area. Avoid placing it behind monitors, lamps, or inside bookshelves. The ideal placement is on a wall at eye level (approximately 48 to 60 inches from the floor) or on a flat surface facing the center of the room.
2. Verify Orientation: Ensure the sensor is not facing a heat source. If the PIR lens is pointed directly at a radiator, a sunny window, or a heat-venting electronic device, the "thermal noise" can blind the sensor, making it unable to distinguish a human body from the background heat.
3. Refresh the Connection: On the main Ecobee Enhanced screen, navigate to Main Menu > Sensors. Select the specific sensor that is reporting as unoccupied. Toggle the "Participate in Smart Home/Averaging" setting off and then back on to force a handshake between the sensor and the thermostat.
4. Test the Trigger: Stand 6 feet away and perform a large, sweeping motion with your arms. Wait up to 60 seconds for the wireless signal to travel from the sensor to the thermostat. Check the Sensors menu again to see if the status has flipped to "Occupied."

If That Didn't Work

• Replace the Batteries: Low battery voltage can cause the PIR sensor to lose sensitivity or fail to transmit the occupancy signal even if it detects motion. Replace the existing batteries with fresh CR2032 lithium coin cells. Ensure the battery tabs are fully seated and the contacts are clean.
• Perform a Hard Sensor Reset: Remove the batteries from the sensor for a full 60 seconds. While the batteries are out, press and hold the pairing button (if applicable to your specific sensor revision) or simply leave it powered down. Reinsert the batteries and re-pair the sensor through the thermostat's Sensors > Add Sensor menu.
• Check for Signal Interference: If the sensor is located more than 30 feet from the thermostat or separated by thick masonry/metal studs, the "Occupied" signal may be dropped. Try moving the sensor temporarily to the same room as the thermostat. If it works perfectly there, you have a range issue and may need to move the thermostat or the sensor to a more central location.
• Update Firmware: Ensure your Ecobee Enhanced is running the latest firmware. Go to Main Menu > Settings > Installation Settings to verify connectivity. Firmware updates often include refinements to the PIR detection algorithms to reduce false negatives.

Heads Up

• The "Stillness" Gap: Be aware that PIR sensors are designed to ignore "static" heat. If you are sleeping or meditating, the sensor will eventually mark the room as unoccupied. This is normal behavior.
• Avoid Direct Sunlight: Never place a sensor in direct sunlight. The intense IR radiation from the sun can "wash out" the sensor, rendering it unable to detect the smaller heat signature of a human.
• Cleaning the Lens: Dust buildup on the small plastic dome of the sensor can refract the IR signal. Gently clean the lens with a dry microfiber cloth; avoid using liquid cleaners which can leave a film that obscures the sensor's view.
• Follow Me Logic: Remember that if you have "Follow Me" enabled, the thermostat will prioritize the temperature of the *most recently occupied* sensor. If multiple sensors are reporting, the one with the most recent motion trigger takes precedence.