Indoor unit shows F3; heating performance is poor or unit stops in heating mode.

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.

Possible Causes

Failed outdoor coil sensor, Loose or corroded sensor connector, Sensor not in proper contact with coil, Faulty outdoor PCB

Safety: Turn off power at the disconnect.

Step 1 – Access outdoor coil sensor: Remove outdoor panel and locate the sensor on the condenser coil or refrigerant line.
Step 2 – Check attachment: Ensure the sensor is firmly clipped or strapped to the coil/line.
Step 3 – Inspect wiring: Look for damage or corrosion. Clean and reseat the connector.
Step 4 – Replace sensor: If faulty, install a new Senville outdoor coil sensor.
Step 5 – Verify operation: Run the unit in heating mode and confirm F3 does not reappear.

Medium 3/5

Condenser Temperature Sensor (T2)

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