Thermostat reports that a remote room sensor is not detected or shows 'N/A'

Safety: For wired sensors, turn off power to the furnace/air handler before touching any low-voltage wiring. Wireless sensors require no power-off.

• Step 1 – Identify sensor type: Determine if the missing sensor is a wired remote sensor (S1/S2) or a wireless SmartSensor.
• Step 2 – For SmartSensors: Replace the battery, ensure the sensor is within 45 feet of the thermostat, and re-pair it via Menu > Settings > Sensors.
• Step 3 – For wired sensors: Remove the thermostat and verify the sensor wires are firmly connected to the S1/S2 terminals. At the sensor location, check that the wires are secure.
• Step 4 – Continuity test: With power off, disconnect one end of the sensor wires and use a multimeter to check continuity between the two conductors. An open reading indicates a broken cable that must be repaired or replaced.
• Step 5 – Replace sensor: If wiring is intact but the sensor still reads open, replace the remote sensor with a compatible ecobee or OEM sensor.