Thermostat shows E02 and cannot read room temperature correctly; display may show dashes or a fixed value.

Safety: Turn off power to the thermostat and HVAC system at the breaker before working on wiring.

Steps:

• Remove the thermostat from the wall plate to access the wiring terminals.
• Locate the remote sensor terminals (often labeled S1/S2, RS+, RS−, or similar in Schneider Electric documentation).
• Verify that the remote sensor cable is firmly connected and that no bare conductors are touching each other or other terminals.
• At the thermostat end, disconnect the sensor wires and measure resistance across the two sensor conductors with a multimeter. Compare to the Schneider Electric remote sensor spec (typically 10kΩ NTC at 25°C, but confirm in manual). Infinite or near-zero resistance indicates a bad sensor or shorted cable.
• If resistance is correct at the sensor head but not at the thermostat, the cable is damaged; inspect for staples, cuts, or crushed sections and replace the cable if needed.
• If the sensor itself is faulty, replace it with a compatible Schneider Electric remote room sensor and reconnect to the same terminals.
• Restore power and confirm that E02 clears and the room temperature reading is reasonable.