Panasonic mini split error code F99

Common causes

• A shorted or failing compressor winding.
• A failed inverter module.
• Loose compressor terminals.

How to fix it yourself

Do the reset and the visual checks, but the underlying repair needs a technician with a meter and the service manual.

1. Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
2. With power off, check the compressor terminals.
3. Do not keep resetting.

Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.

When to call a technician

Technician diagnosis of compressor windings and the inverter.

Which Panasonic units show F99

This page applies to Panasonic Exterios, ClimaPure and Multi-zone (CU-xE) units. Panasonic's own documentation lists F99 as "Outdoor DC peak detection (inverter over-current)", the same definition used across the Panasonic it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where Panasonic shows this code

The indoor unit blinks its Timer lamp when a fault is stored. To read the code, point the remote at the unit and hold the CHECK button (on the back of the remote, under the flap on most models) for about 5 seconds until -- shows, then press the temperature up or down button; each press shows a code, and the unit beeps continuously (not a short beep) when the code shown is the stored fault. H codes are faults (a sensor, motor or board that needs attention). F codes are protections: the outdoor unit stopped itself because of pressure, temperature or current.

Other Panasonic codes

Same part of the system as F99:

All Panasonic error codes