what does C4 mean on a Daikin FTKZ09VV2S or FTKZ12VV2S?
C4 concerns the heat-exchanger temperature sensor in the documented Daikin FTKZ09VV2S and FTKZ12VV2S fault table. it does not show that replacing the sensor alone will solve the problem.
model scope: Daikin FTKZ09VV2S and FTKZ12VV2S.
record the confirmed code and full model for an air-conditioning technician. where a remote check is safe, use the linked model-specific reporting guide and distinguish its confirming long beep from unrelated codes passed during scanning.
stop operation rather than repeatedly resetting the warning. leave sensor access, connections and electrical tests to qualified service; removing a cover to locate the sensor is not a preliminary home check. do not substitute a generic sensor or infer a matching part from C4 alone.
for burning smells, water leakage or repeated breaker trips, do not run another scan. stop and isolate safely, then arrange qualified help. this is not all-model Daikin code guidance.
possible causes
- a heat-exchanger temperature-sensor fault indication; the cause needs service assessment
solutions
diy warning
working on appliances can involve mains electricity, water and moving parts. always disconnect power and water before you start. in Australia, gas work must be done by a licensed gasfitter, and fixed (hard-wired) electrical work by a licensed electrician. everything on this site is guidance only, and any repair you carry out is at your own risk. we are not responsible for any damage or injury caused by attempting a repair. if you are not confident, please use a qualified technician.
