honeywell t9 keeps switching to a room i'm not in, how do i make it follow me?

Diagnosis

The Honeywell Home T9 RCHT9610WFSW2003 utilizes a "Priority" system to determine which temperature sensor dictates the HVAC system's behavior. When the thermostat "switches" to a room you aren't in, it is usually because the device is set to a specific room priority (Static) or the motion sensors in the room you are currently in are failing to trigger a "Presence" update. This results in the thermostat ignoring your current location and defaulting back to a pre-selected room or the main wall unit. This happens because the T9 does not actually "follow" you in real-time like a GPS; instead, it relies on Passive Infrared (PIR) sensors within the wireless remote sensors to detect heat signatures and movement. If a sensor is placed behind a curtain, too far from your seating area, or if the "Priority" setting is locked to a specific zone, the system will not shift the temperature target to your current location. You can confirm this by checking the home screen; the room name displayed next to the current temperature indicates which sensor is currently controlling the system.

How to Fix It

To enable the dynamic motion-sensing feature and ensure the thermostat prioritizes the room you are actually occupying, follow these precise steps:

1. Wake the thermostat by tapping the screen. Press the Menu icon on the bottom right of the home screen.
2. Navigate to the Priority menu option and select it.
3. You will see a list of all paired wireless sensors and the main thermostat unit. Look for the toggle or selection for Occupied or Automatic.
4. Select the Occupied (or "Follow Me") setting. This tells the T9 to ignore static room assignments and instead prioritize any sensor that currently detects motion.
5. If you have multiple rooms occupied, the T9 will average the temperature of all "active" rooms. To test this, walk into a room with a sensor and wait 30-60 seconds; the home screen should update to show that room's name as the active priority.
6. Exit the menu by pressing the Home button to save your changes.

If That Didn't Work

• Relocate the Wireless Sensor: PIR sensors have a limited field of view (usually around 120 degrees). If the sensor is tucked in a corner or blocked by furniture, it won't detect you. Move the sensor to a wall where it has a clear line of sight to the area where you spend the most time. Ensure it is mounted between 4 and 6 feet off the floor for optimal detection.
• Check Battery Levels: Low batteries in the wireless sensors can cause the motion detection circuit to fail before the temperature reporting circuit does. Replace the batteries with high-quality alkaline AA batteries. If the battery icon on the T9 screen for that specific room is flashing or low, the "Follow Me" logic will ignore that sensor entirely.
• Verify Sensor Pairing: If a specific room never becomes the priority, the sensor may have lost its bond with the T9. Go to Menu > Sensor Setup and remove the problematic sensor, then re-add it by pressing the pairing button on the sensor until the thermostat recognizes the device.
• Disable Conflicting Schedules: Ensure you aren't in a "Sleep" or "Away" mode that overrides priority settings. Some pre-set schedules force the system to prioritize the Master Bedroom regardless of motion in the living room. Switch the system to Manual mode to see if the motion priority begins working.

Heads Up

• Avoid Heat Sources: Do not place wireless sensors near lamps, electronics, or in direct sunlight. The PIR sensor may mistake a heat-emitting appliance for human motion, causing the thermostat to "follow" a toaster or a sunny window.
• Averaging Logic: Remember that when multiple rooms are occupied, the T9 averages the temperature. If one room is 75°F and another is 68°F, the system will target the middle ground, which may feel like it isn't "following" you perfectly.
• Signal Range: The wireless sensors use a proprietary 900MHz signal. If a sensor is more than 60 feet away or separated by heavy masonry/metal studs, the motion trigger may lag or fail to reach the main unit.
• Firmware Updates: Ensure your T9 is connected to a stable 2.4GHz Wi-Fi network. Honeywell pushes "Over-the-Air" (OTA) updates that frequently refine the motion-sensing algorithms and sensor polling intervals.