Panasonic F11 error code: four-way valve switching fault

What Does Error F11 Mean?

Panasonic assigns F11 to a four-way valve switching abnormality. The system commanded the reversing valve to change between heating and cooling, then read the coil temperatures and did not see the change it expected, so it stopped. It points at the valve, its coil, the wiring, or the sensors used to confirm the switch. Applies to: Panasonic reverse-cycle wall split systems that report F11 in the self-diagnosis table This meaning follows Panasonic self-diagnosis literature for reverse-cycle wall split systems that list F11. Cooling-only models do not have a four-way valve, and other Panasonic ranges use different code tables, so confirm the model is a heat pump and check both model numbers. Owner-safe checks: Note which mode the unit was in or changing to when F11 appeared, and whether it had just come out of a defrost cycle. | Note whether the air was the wrong temperature for the selected mode before the unit stopped. Qualified technician: Testing the reversing valve solenoid, inspecting the valve, and reading pressures across it require a technician with gauges, and replacing the valve is sealed-circuit work.