HVAC Code Lookup

Fujitsu Mini-Split: 2 Flashes

A Fujitsu mini-split LED pattern starting with 2 flashes matches 6 documented codes: 21, 22, 23, 24, 26, 29. Watch the full pattern (short vs. long flashes) to tell them apart — all 6 are explained below.

Code 21: Number of wires and pipes error on a multi-zone system

Soft lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 1 time, ECONOMY lamp blinking continuously

Number of wires and pipes error on a multi-zone system. The number of wired zones does not match the number of piped zones, or wiring and piping have been crossed between rooms.

Manual wording: “Number of Wires and Pipes Error - When the operation command is inputted by the remote controller without check operation completion.”

Documented for: RLF / RLF1 multi-zone indoor units on RLXFZ multi-zone outdoor units

Likely causes, most common first

  1. Crossed wiring or crossed refrigerant piping between indoor units and the branch box or condenser
  2. An indoor unit that is piped but not wired (or wired but not piped)
  3. Operation command sent before check-run was completed

When to call a technician

This is an installation error. The wiring and piping between the outdoor unit, branch box and each indoor head must be traced and corrected by the installing contractor.

A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Fujitsu code 21

Code 22: Indoor unit capacity error on a multi-zone system

Soft lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 2 times, ECONOMY lamp blinking continuously

Indoor unit capacity error on a multi-zone system. The total capacity of the connected indoor units is above the maximum or below the minimum the outdoor unit will accept.

Manual wording: “Indoor Unit Capacity Error - The total capacity of the indoor units has been exceeded or is under the minimum acceptable range.”

Documented for: RLF/RLF1, LPAS and LUAS1 multi-zone indoor units; AOU48RLXFZ shows E221

Likely causes, most common first

  1. Too much or too little total indoor capacity connected to the condenser
  2. Broken field wiring so the condenser cannot see one or more indoor units
  3. Failed indoor controller PCB on the missing zone

What you can safely check yourself

  • Check that every indoor head still has power (breaker and any zone disconnects on)
  • Turn the system off at the breaker for about 5 minutes, then back on

When to call a technician

Fujitsu notes that on multi-zone systems this code usually means the condenser has lost communication with one or more heads. Tracing that takes meter work on field wiring, so call a technician.

A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Full page for Fujitsu code 22

Code 23: Combination error

Hard lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 3 times, ECONOMY lamp blinking continuously

Combination error. The outdoor unit has detected that the indoor unit connected to it is not a matching model - for example a multi-zone indoor head wired to a single-zone condenser, or an unsupported condenser on a multi-zone system.

Manual wording: “Combination Error - The outdoor unit received a signal that the applied indoor unit is that of a multi type.”

Documented for: RGLX, RL2/RLS3/RLB/RLXB wall mounted, RLF/RLF1 multi-zone

Likely causes, most common first

  1. Mismatched indoor and outdoor unit models
  2. Incorrect wiring between the indoor and outdoor units
  3. An unsupported multi-zone condenser installed for the indoor units fitted
  4. Failed outdoor main PCB (after the model match is confirmed correct)

When to call a technician

This means the equipment pairing or wiring is wrong. Only the installing contractor can verify model matching and correct the connection.

A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Fujitsu code 23

Code 24: Number of indoor units error or number of branch boxes error

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

  1. Too many or too few indoor units connected for the outdoor unit
  2. A branch box not powered up
  3. 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

Full page for Fujitsu code 24

Code 26: Address setting error in the wired remote controller system

Soft lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 6 times, ECONOMY lamp blinking continuously

Address setting error in the wired remote controller system. Auto-set and manually-set controller addresses are mixed in one remote controller group, or the same address number is duplicated in one group.

Manual wording: “Address Setting Error in Wired Remote Controller System - When the address number set by auto setting & manual setting are mixed in on RC group.”

Documented for: RGLX, RL2/RLS3/RLB/RLXB, RLF/RLF1 with UTY-series wired remote controllers

Likely causes, most common first

  1. Wrong wiring connection within the remote controller group
  2. Auto address (00) and a manual address mixed in one remote controller group
  3. Duplicate remote controller addresses in one group
  4. Damaged indoor controller PCB

When to call a technician

Remote controller addressing is a commissioning setting done through the wall controller's service menus. Call the installing contractor.

A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Fujitsu code 26

Code 29: Connection unit number error

Soft lockoutShown as: OPERATION lamp blinks 2 times, TIMER lamp blinks 9 times, ECONOMY lamp blinking continuously

Connection unit number error. The number of indoor units connected in the remote controller group is outside the rule the control allows.

Manual wording: “Combination Unit Number Error - When the number of connecting indoor units are out of a specified rule.”

Documented for: RGLX, RL2/RLS3/RLB/RLXB, RLF/RLF1 with wired remote controllers

Likely causes, most common first

  1. Wrong number of indoor units wired into the group
  2. Damaged indoor unit controller PCB

When to call a technician

The unit count is set by field wiring and controller addressing. This has to be corrected by the installing contractor.

A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Full page for Fujitsu code 29

Other Fujitsu codes