ACiQ mini split error code EF
2 meanings on ACiQ, depending on which series you have. Check the model number on the indoor unit's label.
If yours is a standard single-zone and multi-zone (ACiQ-09Z-HP…, Midea-built) unit
Intelligent eye (occupancy sensor) module error.
- TypeFault
- SystemControl board
- Can I fix it?Usually a homeowner fix
What EF means on a ACiQ
On units with an occupancy sensor (the 'intelligent eye' that sets back the temperature when the room is empty), the sensor module failed its self-check. Heating and cooling keep working.
On this platform, EF is a fault: something has failed or is disconnected and needs diagnosis.
Common causes
- A loose sensor module plug.
- A dirty or blocked sensor window.
- A failed sensor module.
How to fix it yourself
You can almost always clear this yourself with the steps below.
- Turn the follow-me / intelligent-eye function off from the remote to keep using the unit normally.
- 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.
- With power off, reseat the sensor module plug behind the front panel.
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
Optional repair; the unit works without the sensor.
If yours is a K-series (ACiQ-K09W-HP…, TCL-built) unit
Outdoor DC fan motor fault.
- TypeFault
- SystemFan motor
- Can I fix it?Homeowner checks, then maybe a tech
What EF means on a ACiQ
The outdoor fan is not reaching or reporting the commanded speed. The compressor stops because it cannot reject heat.
On this platform, EF is a fault: something has failed or is disconnected and needs diagnosis.
Common causes
- Ice, snow, leaves or debris blocking the fan.
- Worn bearings or a failed motor.
- A loose fan connector or damaged wiring.
- A failed fan drive on the board.
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.
- 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.
- 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.
- With power off, spin the outdoor fan by hand; it should turn freely.
- Reseat the fan motor connector.
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
Fan motors are replaceable but sit next to the inverter; call a technician if the fan spins freely and the plug is tight.
Which ACiQ units show EF
ACiQ sells Standard single-zone (ACiQ-09Z-HP…B / W-HP) and multi-zone and K-series (ACiQ-K09W-HP…, SZDM / WHP / KZHP) units, and this code carries more than one meaning across them: on the standard single-zone and multi-zone (ACiQ-09Z-HP…, Midea-built), EF means intelligent eye (occupancy sensor) module error; on the K-series (ACiQ-K09W-HP…, TCL-built), EF means outdoor DC fan motor fault. The model number on the indoor unit's label, and which display you are reading, tell you which applies.
Where ACiQ shows this code
standard single-zone and multi-zone (ACiQ-09Z-HP…, Midea-built): The code appears on the indoor unit's LED display in place of the set temperature. Some models also blink the indicator lamps in a pattern that matches the code. E codes are faults in the indoor unit or its communication link, F codes are faults on the outdoor side, and P codes are protections: the outdoor unit has stopped itself to prevent damage. EC is the refrigerant leak check.
K-series (ACiQ-K09W-HP…, TCL-built): The indoor display shows the code in place of the set temperature. E codes are faults: something has failed and needs diagnosis. P, H, d and F codes are protections: the system stopped or throttled itself to prevent damage, and many clear on their own once conditions return to normal.
Other ACiQ codes
Same part of the system as EF:
EF on other brands
The same characters do not always mean the same thing. Check the brand on your unit.
- Pioneer EF Intelligent eye (occupancy sensor) module error
- Zone Air EF Outdoor DC fan motor fault
Questions people ask
Why does EF have more than one meaning on a ACiQ?
ACiQ sells units built on more than one control platform, and each platform has its own code table. The model number on the indoor unit's label tells you which series you have: standard single-zone and multi-zone (ACiQ-09Z-HP…, Midea-built) units read EF as intelligent eye (occupancy sensor) module error; K-series (ACiQ-K09W-HP…, TCL-built) units read EF as outdoor DC fan motor fault.
Can I reset a ACiQ EF code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If EF comes back, the fault is real and needs the checks above.
Is it safe to keep running a ACiQ showing EF?
The unit will usually refuse to run, or run with reduced output, until the fault is cleared. Repeated resets do not fix anything and can mask a problem that is getting worse.
Sources
- ACiQ Standard Single-Zone Mini Split Service Manual (SZ-Z-HP / W-HP), Quick Maintenance by Error Code
- ACiQ Mini-Split Air Handler and Condenser Service Manual (MS-SZDM / WHP / KZHP), error code table
Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.