Daikin · Mini-split
U0 Refrigerant shortage
What this code means
The system is detecting a low refrigerant charge, which can point to a leak.
Most likely causes
- Refrigerant leak somewhere in the line set
- Undercharged system from installation
What to try first
This requires refrigerant handling, which is federally regulated and needs an EPA 608-certified technician.
Safety first: stop using the appliance and shut off its gas or power until it has been inspected — this fault category is associated with fire or gas risk.
FAQ
What does Daikin error code U0 mean?
Refrigerant shortage. The system is detecting a low refrigerant charge, which can point to a leak.
Can I fix Daikin code U0 myself?
No — stop using the appliance and shut off its gas or power until it has been inspected. This fault category is associated with fire or gas risk.
What causes Daikin code U0?
The most common causes are: refrigerant leak somewhere in the line set; undercharged system from installation.
Other Daikin mini-split codes
All Daikin mini-split error codes →
Other mini-split brands: Mitsubishi · LG · Fujitsu · Gree · Carrier · Generic · Panasonic
This information may contain errors or not apply to your exact model — always double-check it against your appliance's own manual before acting. If there's any chance of a gas, fire, electrical, carbon monoxide, or other safety hazard, stop and call a licensed professional or the appropriate agency (e.g. your gas utility) instead of relying on this page alone.