Daikin R71FUV1 Service Manual page 460

Troubleshooting by Remote Controller
Remote Controller Display
UF
Applicable Models
RZQ(S)-B/C
Method of Error Detection
Check the transmission between the indoor and outdoor
units with a micro-computer when the power turned ON.
Detect by checking the following temperature differences
during compressor operation.
A: Difference in temperature detected by the indoor
heat exchanger thermistor (R2T) and the indoor
suction air thermistor (R1T)
B: Difference in evaporation temperature (Te) (or
condensation temperature (Tc) during heating
operation) detected by the indoor heat exchanger
thermistor (R2T) and the compressor sensor
Error Decision Conditions
When the transmission wiring between the indoor and
outdoor units is incorrect
When the following conditions continue for 20 minutes
during compressor operation
A: R2T – R1T < 4ºC, and
B: R2T – Te (or Tc during heating operation) > 14ºC
(24ºC during heating operation)
Supposed Causes
Defective transmission wiring between the indoor and
outdoor units
Mismatching of wiring and piping
Refrigerant shortage
Clogged refrigerant piping system
Si20-701_B
453