Panasonic mini split error code H21

Common causes

• A blocked or kinked condensate drain.
• A drain line without continuous fall.
• A failed drain pump.
• A stuck float switch.

How to fix it yourself

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

1. Confirm water flows from the drain outlet while cooling.
2. Clear the drain with a wet/dry vacuum at the outlet.
3. Check the drain line for dips.
4. If a pump is fitted, check it runs and the float moves freely.

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 technician can replace a failed pump or float switch.

Which Panasonic units show H21

This page applies to Panasonic Exterios, ClimaPure and Multi-zone (CU-xE) units. Panasonic's own documentation lists H21 as "Indoor float switch operated (drain)", 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

All Panasonic error codes