Panasonic mini split error code H99

Common causes

• Dirty filters or coil.
• Cooling with the fan on Low in a cold room.
• Low refrigerant charge.

How to fix it yourself

You can almost always clear this yourself with the steps below.

1. Pull the front panel and check the filters and the indoor coil. Dirty filters and a matted coil restrict airflow, and airflow problems trigger a surprising number of protection codes.
2. Run Fan-only until any ice is gone, then raise the fan speed and set temperature.
3. If it recurs with clean filters, have the charge checked.

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

A charge check if it persists.

Which Panasonic units show H99

This page applies to Panasonic Exterios, ClimaPure and Multi-zone (CU-xE) units. Panasonic's own documentation lists H99 as "Indoor freeze prevention (cooling)", 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 H99:

All Panasonic error codes