The outdoor unit does not operate correctly; H23 is displayed, often 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

Open or shorted outdoor coil thermistor, Damaged sensor wiring, Faulty outdoor PCB sensor input

Safety first: Turn off power at the outdoor isolator.

Steps:

1. Access the outdoor coil: Remove the front or side panel to expose the condenser/heat pump coil.
2. Locate the coil sensor: Find the thermistor clipped to the coil tubing or fins, usually near the middle of the coil.
3. Inspect and reseat: Check that the sensor is firmly attached and the wiring is intact. Reseat the connector on the outdoor PCB.
4. Resistance test: With power OFF, unplug the sensor and measure its resistance. Compare it to Panasonic specifications. Replace if open/shorted.

If the sensor is good but H23 persists, the outdoor PCB is likely at fault and should be replaced by a professional.

Hard 4/5

Outdoor Coil Thermistor

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