Error code
18 Outdoor heat-exchanger or suction sensor fault
How it shows on the unit Shown on the remote control display in service-check mode (CHECK button); all indoor-unit lamps flash 5 times per second
Applies to 4 models
RAS-25G2KVP-ND, RAS-35G2KVP-ND, RAS-25G2AVP-ND, RAS-35G2AVP-ND
What this means
The outdoor heat-exchanger sensor (TE) or the suction-pipe sensor (TS) is out of place, disconnected or short-circuited. Everything stops.
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.
Using Claude Code or Meta Muse? Connect HeatPump AI and ask it about 18.