E09
Johnson Controls
Occupancy / PIR Sensor Failure
E09 displayed and thermostat cannot detect occupancy; smart setback or presence features disabled.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Failed PIR occupancy sensor on front bezel, Disconnected sensor ribbon cable, Obstructed sensor window, Firmware not recognizing sensor module
How to Fix / Troubleshooting
Safety: Turn off power to the thermostat at the HVAC breaker before removing the unit from the wall.
- Step 1 – Clean sensor window: Gently clean the front lens area of the thermostat with a soft, dry cloth to remove dust or smudges that may block the PIR sensor.
- Step 2 – Reboot and test: Power cycle the system and walk in front of the thermostat to see if occupancy is detected (if your model shows an icon).
- Step 3 – Inspect internal connection: Remove the thermostat from the sub‑base. Look for a small ribbon cable or connector from the PIR sensor module to the main PCB. Ensure it is fully seated.
- Step 4 – Disable feature if unused: In the installer menu, you can disable occupancy‑based control to clear the error if you do not need this feature.
- Step 5 – Replace front bezel or thermostat: If E09 persists, replace the occupancy sensor/front bezel assembly or the entire thermostat, depending on model design.
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Repair Difficulty
Medium
3/5
Required Part
Occupancy Sensor Module
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