Panasonic mini split error code H12

Common causes

• An unsupported combination of indoor units.
• An indoor unit not communicating so the total looks wrong.

How to fix it yourself

Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician.

1. Confirm every indoor unit has power and shows no code of its own.
2. Check the combination against Panasonic's table.

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

Installer correction.

Which Panasonic units show H12

This page applies to Panasonic Exterios, ClimaPure and Multi-zone (CU-xE) units. Panasonic's own documentation lists H12 as "Indoor and outdoor capacity mismatch (multi-split)", 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 H12:

All Panasonic error codes