Fujitsu Air Conditioner 63 Error Code

Inverter error on Fujitsu air conditioners.

Fujitsu All Fujitsu air conditioner codes

May need a pro

The outdoor inverter circuit, which drives the compressor, reported a fault. Loose board connections or a failed inverter board are the usual causes.

Compatible models

Fujitsu inverter outdoor units for its wall-mounted, RGLX and RLF lines, plus the LZAH series and AOU48RLXFZ (as E631).

Also shown as

Lamp pattern: Operation lamp 6 flashes, Timer lamp 3 flashes. Listed as 63.1 or 63.2 in FGLair. On AOU48RLXFZ outdoor units it appears as E631.

Difficulty

Try the basic checks, but the usual fix is a technician's job.

How to fix
When to call a pro
Parts
FAQ

Not sure you are reading the code right? See how to read Fujitsu air conditioner codes.

Safety first: unplug the air conditioner (or switch off its breaker) before touching filters, hoses or panels. If you smell burning or gas, or see water near the outlet, stop and call a professional.

How to fix Fujitsu 63

Reset once
Do a breaker reset.
Stop after one retry
If 63 reappears, leave the system off rather than cycling it again and again.

When to call a technician

Inverter faults involve high-voltage parts that stay charged after the power is off. Leave diagnosis to an HVAC technician.

Parts linked to 63

These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.

Outdoor control and inverter board

Order parts by your full model number so they fit.

Frequently asked questions

Which Fujitsu models show the 63 code?

Fujitsu inverter outdoor units for its wall-mounted, RGLX and RLF lines, plus the LZAH series and AOU48RLXFZ (as E631).

Can I fix Fujitsu 63 myself?

Only the basic checks. You can safely try the steps above, but 63 usually points to a part or fault that needs a technician.

Other Fujitsu air conditioner codes

Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.

Sources we checked