Fujitsu air conditioner 12 error code: wired remote not communicating with indoor unit
Also shown as E12
- Urgency
- Low
- Who can fix it
- Moderate DIY
- Time
- About 20 min
- Repair cost
- $150–$450
What the 12 code means
Error 12 on a Fujitsu mini-split means the indoor unit has not received a signal from the wired remote controller for more than a minute. The lamp pattern is 1 operation blink and 2 timer blinks, with the economy lamp flashing continuously.
A wired remote sends a steady signal to the indoor unit over a thin low-voltage cable. Fujitsu's troubleshooting guide says the indoor unit shows error 12 when it cannot receive that signal for more than 1 minute during normal operation.
Because the remote cannot talk to the indoor unit, the code may appear only on the indoor unit's lamps, as 1 operation blink and 2 timer blinks.
Common causes
Listed from most to least common.
- Loose wire at the wired remote or the indoor unit terminal
- Remote cable cut, pinched or damaged in the wall
- Wired remote controller failed
- Indoor unit controller board fault
How to fix the 12 code
Unplug the air conditioner or switch it off at the breaker before removing any panel or filter.
Step 1: Reset the power
Turn the system off at the breaker for 5 minutes and back on. The remote and indoor unit restart and try to reconnect.
Step 2: Check the remote is seated
If the wired remote clips onto a wall plate, make sure it is pushed fully onto the plate. Do not pull it off with the power on.
Step 3: Think about recent work
If someone has drilled, painted or hung pictures near the remote cable, the cable may be damaged. Tell your technician.
Step 4: Use the handheld remote if you have one
Some units also accept a wireless remote. If it still works, the indoor unit itself is likely fine and the wired remote or its cable is at fault.
How to reset the Fujitsu air conditioner
- Turn the system off with the remote or wired controller.
- Switch off the breaker for the system, and the outdoor disconnect switch if there is one. Leave the power off for at least 5 minutes.
- Restore power and turn the unit back on. The compressor normally waits a few minutes before starting, so give it time before judging.
- If the same code or blink pattern comes back, the fault is still there. Work through the fix steps above, or call a Fujitsu contractor or other licensed HVAC technician.
When to call a technician
If error 12 returns, have a technician check the remote cable and terminals and test the remote and indoor board. Fujitsu's check is the terminal connection and the cable between the remote and indoor unit.
A typical repair for this code costs $150–$450 in the US, including parts and labor. Prices vary by area and model.
Models this applies to
- Halcyon wall-mounted mini-splits (ASU indoor, AOU outdoor)
- Halcyon floor, ceiling cassette and slim duct units (AGU, AUU, ARU)
- Halcyon multi-zone systems (RLF series)
- Ducted and ceiling-suspended units (RGLX, RULX series)
Codes can differ slightly between models. Your owner's manual is the final word and is available from Fujitsu support.
Frequently asked questions
›Is error 12 serious?
Not usually. The refrigerant system is not involved. The problem is in the remote, its cable or the indoor board, which are cheaper to fix than outdoor faults.
›Can I replace the Fujitsu wired remote myself?
It is low-voltage wiring, but it must match your indoor unit and be wired and set up correctly. Most owners have a technician do it.
›Does error 12 mean the same thing on every Fujitsu?
On the wall, floor, ducted and cassette models in Fujitsu's US troubleshooting guide, yes. Some multi-zone and newer outdoor units use their own code tables, so check the manual for your model.