Daikin UAL-A Series, Engineering Data

Page: 46 / 52

45
8
The LED indicator
of the unit displays
ER20 and the wired
controller displays 20
High pressure of #1
The motor has broken down (cooling)
Check and troubleshoot
Circulatory air is shorted (cooling)
The heat exchanger needs cleaning
(cooling)
The fluorine-side filter is clogged up Check and replace.
The water temperature is too high
(heating)
Tune down the water temperature
The water flow is too small (heating) Check and troubleshoot
The water filter is clogged up (heating) Clean the water filter.
The ambient temperature is too high
(cooling)
OFF
Too much refrigerant
Release a proper amount of
refrigerant
Failure of high-voltage modular output
port
Replace the module.
The switch has broken down Replace the pressure switch.
9
The LED indicator
of the unit displays
ER21 and the wired
controller displays 21
Low pressure of #1
Malfunction of heat exchanger during
heating
Check and troubleshoot the
outdoor unit
Malfunction of motor during heating
Check and troubleshoot the
outdoor motor
Insufficient refrigerant or leakage Check and replenish refrigerant
Failure of low-voltage modular input
port
Replace the module
The low pressure sensor has broken
down
Replace the pressure sensor
10
The LED indicator
of the unit displays
ER24 and the wired
controller displays 24
High pressure of #2
The motor has broken down (cooling)
Check and troubleshoot
Circulatory air is shorted (cooling)
The heat exchanger needs cleaning
(cooling)
The fluorine-side filter is clogged up Check and replace.
The water temperature is too high
(heating)
Tune down the water temperature
The water flow is too small (heating) Check and troubleshoot
The water filter is clogged up (heating) Clean the water filter.
The ambient temperature is too high
(cooling)
OFF
Too much refrigerant
Release a proper amount of
refrigerant
Failure of high-voltage modular output
port
Replace the module.
The switch has broken down Replace the pressure switch.
11
The LED indicator
of the unit displays
ER25 and the wired
controller displays 25
Temperature of inlet/outlet water
is too low
The temperature of return water is set
too low
Change the temperature setting
for return water
The water flow is too small, resulting
in a large pressure drop
Check the water system (see item
7 in the table)
12
The LED indicator
of the unit displays
ER26 and the wired
controller displays 26
Overload of electric heater in
water system
Check whether the water system is
equipped with an electric heater
The heating wire of the electric
heater in the water system is
shorted
The heating wire of the electric heater
in the water system is shorted
Replace the electric heater of the
water system