U0 " Low Pressure Drop Due To Refrigerant Shortage Or Electronic Expansion Valve Failure - Daikin ALTHERMA HT Service Manual

Troubleshooting by Indication on the Remote Controller
3.53 "U0 " Low Pressure Drop Due to Refrigerant Shortage or
Electronic Expansion Valve Failure
U0
Remote Control
Display
ER*Q 011~016*
Applicable
Models
Short of gas malfunction is detected by discharge pipe temperature thermistor and low pressure
Method of
saturation temperature.
Malfunction
Detection
Microcomputer judge and detect if the system is short of refrigerant.
Malfunction
Malfunction is not decided while the unit operation is continued.
Decision
Conditions
 Out of gas or refrigerant system clogging (incorrect piping)
Supposed
 Defect of pressure sensor
Causes
 Defect of outdoor unit PC board (A1P)
 Defect of thermistor R3T
194
ESIE09-08B
Troubleshooting