DIY HVAC Tools

Daikin mini split error code E3

High pressure protection (high-pressure switch).

  • TypeProtection
  • SystemRefrigerant circuit
  • Can I fix it?Homeowner checks, then maybe a tech

What E3 means on a Daikin

Head pressure exceeded the limit and the high-pressure switch opened. The compressor stops.

On this platform, E3 is a protection: the system stopped or throttled itself to prevent damage; many clear on their own once conditions return to normal.

Common causes

  • A dirty or blocked outdoor coil.
  • The outdoor fan not running.
  • A service valve not fully open.
  • A refrigerant overcharge.
  • In heating, badly restricted indoor airflow.

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. Look at the outdoor unit: clear leaves, cottonwood fluff, snow or ice from the coil and make sure the fan can spin freely and nothing is stacked against the cabinet.
  2. Confirm both service valves are fully open.
  3. 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.
  4. 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.
  5. Anything inside the refrigerant circuit (sensors are fine, but valves, compressors and leaks are not) needs EPA-certified refrigerant handling. That is a technician job.

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 needs gauges to check the charge and the switch.

Which Daikin units show E3

This page applies to Daikin Aurora, 19 Series, Atmosphera, Emura, Quaternity and MXS multi-zone units. Daikin's own documentation lists E3 as "High pressure protection (high-pressure switch)", the same definition used across the Daikin 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 Daikin shows this code

Most Daikin wall units do not show the code on the unit; the operation lamp blinks. To read the code, point the remote at the unit, hold CANCEL (or Timer Cancel) for about 5 seconds until 00 shows, then press CANCEL repeatedly. Each press shows a code; when the unit gives a long continuous beep instead of two short beeps, the code on the remote is the stored fault. Units with a wired controller show the code directly. A and C codes are indoor-unit faults, E, F, H, J, L and P codes are outdoor-unit faults and protections, and U codes are system-level problems such as communication, power supply and refrigerant shortage.

Other Daikin codes

Same part of the system as E3:

A5Freeze-up protection (cooling) or high-pressure control (heating)A9Indoor electronic expansion valve (EEV) faultE4Low pressure protectionEAFour-way (reversing) valve switching faultF6High pressure in cooling (refrigerant overcharge)U0Refrigerant shortage
00No fault stored (normal)A1Indoor unit control board (PCB) failureA3Drain water level abnormal (float switch)A6Indoor fan motor fault (locked or abnormal)C4Indoor heat exchanger (liquid pipe) temperature sensor fault (open or short circuit)C5Indoor heat exchanger (gas pipe) temperature sensor fault (open or short circuit)C7Front panel (open/close) drive faultC9Indoor room (suction air) temperature sensor fault (open or short circuit)

All Daikin error codes

E3 on other brands

The same characters do not always mean the same thing. Check the brand on your unit.

  • Pioneer E3 Indoor fan speed out of control (indoor fan motor fault) / Communication error between outdoor main board and IPM board (outdoor display)
  • Blueridge E3 Low pressure protection (refrigerant shortage or blockage) / Indoor fan speed out of control (indoor fan motor fault)
  • Gree E3 Low pressure protection (refrigerant shortage or blockage)
  • Zone Air E3 Outdoor fan coil (condenser) temperature sensor fault (open or short circuit)
  • Mitsubishi Electric E3 Remote controller signal transmitting error
  • Carrier E3 Indoor fan speed out of control (indoor fan motor fault)
  • Trane E3 Outdoor fan coil (condenser) temperature sensor fault (open or short circuit) / Remote controller signal transmitting error
  • Heil E3 Indoor fan speed out of control (indoor fan motor fault) / Low pressure protection (refrigerant shortage or blockage)
  • ACiQ E3 Indoor fan speed out of control (indoor fan motor fault) / Outdoor fan coil (condenser) temperature sensor fault (open or short circuit)
  • Goodman E3 High pressure protection (high-pressure switch)

Questions people ask

Can I reset a Daikin E3 code myself?

Yes. Turn the system off at the breaker for five minutes, then restart it. If E3 comes back, the fault is real and needs the checks above.

Is it safe to keep running a Daikin showing E3?

Not repeatedly. A protection code means the unit stopped itself to prevent damage, and resetting it over and over can turn a cheap repair into a compressor failure. Reset once, check the basics, and stop if it returns.

Do I need a technician for Daikin E3?

Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician. A technician needs gauges to check the charge and the switch.

Sources

  • Daikin residential (RA) service manuals (error code tables)
  • Daikin operation manuals (remote controller self-diagnosis)

Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.