Error code
24 Unit-number connection fault
How it shows on the unit OPERATION 2 blinks, TIMER 4 blinks (each 0.5 s on/0.5 s off) while ECONOMY flashes rapidly (0.1 s on/0.1 s off)
Applies to 2 models
What this means
Connection-number fault for a secondary indoor unit in Simultaneous Multi, or an indoor or branch unit in Flexible Multi.
When to call a technician
This fault involves refrigerant, pressure, or electrical work that must be handled by a certified technician under EU F-gas rules. Do not attempt to open the refrigerant circuit, access mains wiring, or adjust pressure components yourself. Contact a qualified installer or servicer for this one.
See the Fujitsu manual (hosted by an authorized distributor)Hosted by an authorized distributor rather than by the manufacturer. We link to manuals, we never host them.
Using Claude Code or Meta Muse? Connect HeatPump AI and ask it about 24.