MRCOOL air conditioner F5 error code: outdoor fan speed out of control
Also shown as EC 07
- Urgency
- Medium
- Who can fix it
- Moderate DIY
- Time
- About 20 min
- Repair cost
- $200–$700
What the F5 code means
F5 on a MRCOOL mini-split means the outdoor fan is running outside its normal speed range. Gen 4 and Gen 5 units show it as EC 07. MRCOOL says it usually points to the outdoor fan or a loose connection on the outdoor control board.
The outdoor fan is a DC motor whose speed the board checks. If the fan runs too slow, too fast or not at all for a set time, the board stops the system.
A seized fan usually means the motor needs replacing. A fan that spins freely but still trips F5 usually points to the board or its wiring.
Common causes
Listed from most to least common.
- Leaves, snow, ice or debris blocking the outdoor fan
- Fan motor bearings seized or stiff
- Loose wire on the outdoor control board
- Fan motor failed
- Outdoor control board fault
How to fix the F5 code
Unplug the air conditioner or switch it off at the breaker before removing any panel or filter.
Step 1: Turn off the power
Switch off the breaker and the outdoor disconnect before touching the fan.
Step 2: Clear the fan
Remove leaves, snow or ice from around the fan grille. Wear gloves.
Step 3: Spin the fan by hand
With the power off, give the blades a gentle spin through the grille with a stick. MRCOOL says a stiff fan points to the motor, while a free fan points to the board.
Step 4: Reset and test
Restore power and watch the fan start. If F5 returns, book a repair and tell the technician what you found.
You'll need: Work gloves, flashlight.
How to reset the MRCOOL air conditioner
- Turn the mini-split off with the remote.
- Switch off the breaker for the system and the outdoor disconnect switch. MRCOOL suggests leaving the power off for 15 minutes so the boards fully reset.
- Restore power and turn the unit back on. The compressor normally waits about 3 minutes before starting, so give it time before judging.
- If the same code comes back straight away, the fault is still there. Work through the fix steps above, or call a technician.
When to call a technician
If the fan is clear and F5 returns, a technician needs to test the fan motor and outdoor board. Do not open the outdoor electrical box yourself.
A typical repair for this code costs $200–$700 in the US, including parts and labor. Prices vary by area and model.
Models this applies to
- DIY Series ductless mini-splits (Gen 1 to 5), single-zone and multi-zone
- Advantage Series mini-splits
- Olympus Series mini-splits
- EZ-PRO mini-splits
Codes can differ slightly between models. Your owner's manual is the final word and is available from MRCOOL support.
Frequently asked questions
›Can snow or ice cause F5?
Yes. Ice can lock the fan blades. Clear it gently and keep the unit raised above the snow line.
›What is E3 on a MRCOOL?
E3 (EH 03 on Gen 4 and 5) is the same fault for the indoor fan. MRCOOL lists debris, loose wires, a failed motor or a board fault.
›Can I run the AC with F5?
No. Without the outdoor fan the unit cannot shed heat, so it shuts down. Leave it off until fixed.