Fujitsu Mini-Split Code 24
Soft lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 4 times, ECONOMY lamp blinking continuously
Number of indoor units error or number of branch boxes error. The total number of connected indoor units is outside the allowed range of 2 to 8, or the two branch boxes report a different number of units.
Manual wording: “Number of Indoor Units Error / Number of Branch Boxes Error - When the total connection number of indoor units is outside of range between 2 and 8.”
Documented for: RLF / RLF1 multi-zone indoor units on branch-box (HFI Flex) systems
Likely causes, most common first
- Too many or too few indoor units connected for the outdoor unit
- A branch box not powered up
- Mismatch between branch box 1 and branch box 2 unit counts
What you can safely check yourself
- Confirm the branch boxes still have power at their breakers or disconnects
- Turn the whole system off at the breaker for about 5 minutes and back on
When to call a technician
Branch box configuration and unit counts are set at install. A technician has to verify the branch box power and the connected unit count.
A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- 410A Mini-Split Troubleshooting Guide (Part # 6-26-FG2020 Rev. 5/2019) (Fujitsu General America, Inc., All R410A Halcyon mini-splits: RGLX, RL2/RLS3/RLS3H/RLS3Y/RLB/RLXB/RLXEH wall mounted, RLF/RLF1 multi-zone indoor units, RLXFZ multi-zone outdoor units, RML/RMLQ, RULX/RSLX universal-mount, RCLX cassettes) · checked 2026-08-25