Wet Alarm - Daikin REYQ-TA Series Service Manual

Troubleshooting by Error Code

3.34 Wet Alarm

F4
Error Code
Applicable
All outdoor unit models
Models
Method of Error
In cooling operation, detect the condition under which liquid refrigerant returns to the compressor,
according to the temperature and pressure of each part.
Detection
Error Decision
When the following wet state continues for a period of 90 minutes, an alert is issued.
An error is defined for 120 minutes.
Conditions
When the following wet state continues for a period of 45 minutes, an alert is issued.
Supposed
Causes
Troubleshooting
221
Wet state in outdoor units
Wet state in some of indoor units
Defective suction pipe thermistor
Defective discharge pipe thermistor
Defective high pressure sensor
Defective indoor unit electronic expansion valve
Dirty air filter
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Connect the Service Checker.
Mount a pressure gauge on the
high pressure service port.
Reset the operation, and then
restart the operation.
Are the
characteristics of the
accumulator inlet thermistor and
the suction pipe thermistor
normal?
YES
Are the
discharge pipe
thermistor characteristics
normal?
YES
Are the
high pressure sensor
characteristics
normal?
YES
Service Checker
Use the Service Checker to find indoor units operating under the following conditions:
• Gas pipe temperature – Liquid pipe temperature < 2.5˚C (4.5˚F)
&
• Electronic expansion valve opening < 300 pulses
Stop the relevant indoor units while the
system is in cooling operation, and then
check for the liquid pipe temperature of these
indoor units after the system is stabilized.
The liquid pipe
temperature is low
(equivalent to the evaporating
temperature).
NO
NO
NO
NO
YES
SiUS371614E
Replace the relevant
thermistor.
Replace the discharge
pipe thermistor.
Replace the high
pressure sensor.
Replace the indoor
unit electronic
expansion valve.
Clean the air filters
of the indoor units.
Service Diagnosis