Daikin Mini-Split Code UF
Soft lockout
System is not set yet. During the check operation, the number of indoor units communicating did not match the number that actually changed temperature - meaning the refrigerant piping and the wiring do not run to the same zones.
Manual wording: “UF System is not set yet”
Documented for: RMXS and other multi-zone systems
Likely causes, most common first
- Stop valve is left closed
- Improper connection of transmission wiring between indoor unit and outdoor unit
- Failure to execute check operation
- Defective indoor unit PCB
When to call a technician
UF means the installation is crossed or incomplete - piping to one zone with wiring to another, or stop valves still closed. This has to go back to the installer.
A Daikin mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Service Manual - Multi-Split Type Air Conditioners RMXS-L Series (SiUS181631EA) (Daikin, RMXS48LVJU outdoor, BPMKS048A2U/049A3U branch provider, CTXG/CTXS/FTXS/CDXS/FDXS/FVXS/FFQ indoor units) · checked 2026-08-25