Indoor display shows F1 and unit stops or runs erratically

Safety first: Turn OFF power before removing the indoor cover.

• Step 1 – Locate the room sensor: On TCL wall splits, the ambient sensor is usually near the air intake grille or behind the front panel, connected by thin wires to the PCB.
• Step 2 – Check connection: Ensure the sensor plug is firmly seated on the indoor PCB. Reseat it if loose.
• Step 3 – Inspect sensor body and wires: Look for cuts, crushed insulation, or corrosion. Replace the sensor if physically damaged.
• Step 4 – Replace sensor: If F1 persists, replace the ambient temperature sensor with the correct TCL part. This is usually a simple plug-in replacement.
• Step 5 – PCB check: If a new sensor does not clear F1, the indoor PCB may have a defective sensor input and will need replacement.

Warning: Use only OEM or equivalent NTC sensors with the correct resistance curve; incorrect parts will cause inaccurate temperature control.