Dometic ASCDU15HV 1161 Installation And Operation Manual page 27

Universal Air Conditioning Unit
Problem
The Q3 control is
erratically displaying
the temperature.
The unit is on however
there is no cooling or
heating.
There is no heat.
The evaporator coil is
iced.
The system runs
continuously.
"Ar/FL' is flashing
(Filter Reminder).
"HI / - -" is flashing.
"LO / - -" is flashing.
"HI / PS" is flashing
(High Pressure).
"LO / AC" is flashing
(Low Pressure).
Contact an authorized Dometic servicing dealer if the problem continues or for replacement parts.
I
EN
Possible Reason
A power surge or other event has caused
a processor glitch.
A power surge or other event has caused
a processor glitch.
There is a loose connection.
The inside temperature sensor is installed
incorrectly.
The temperature sensor is out of
calibration.
The unity circuit board is malfunctioning.
The wrong mode has been selected.
The wrong mode has been selected.
There is improper airflow through the
evaporator.
The Air Sensor has been installed in the
improper location.
The filter needs to be cleaned or
replaced.
The high-pressure switch is open (in
cooling) due to improper condenser air
flow.
The low-pressure switch is open due to
low Evaporator flow and/or low return-air
temperatures.
The low-pressure switch is open due to
loss of refrigerant.
The head pressure is above 575 PSI in the
system.
The supply voltage is too low.
Voltage is improperly calibrated.
Possible Solution
Shut the power to the unit off and then back on.
Perform the Restore Factory Default Settings routine and
reprogram the control for functions 19 and 23. Refer to
"Programmable Functions, Ranges, and Factory Defaults" on
page 18.
Check the sensor cables and connections. Refer to "Wiring
Diagram" on page 10.
Check the wiring. Refer to "Wiring Diagram" on page 10.
Calibrate the temperature. Refer to "9: Temperature
Calibration" on page 21.
Replace the unity circuit board. Contact a qualified service
technician to replace and retest the system.
Check the Programmable Functions. Ensure Programmable
Function 19 is set to "CL" and Programmable Function 23 is
set to "h1". Refer to "Programmable Functions, Ranges, and
Factory Defaults" on page 18.
Check the Programmable Functions. Ensure Programmable
Function 19 is set to "CL" and Programmable Function 23 is
set to "h1". Refer to "Programmable Functions, Ranges, and
Factory Defaults" on page 18.
Refer to "General System Troubleshooting" on page 25
before reprogramming the Q3 control.
Change Programmable Function 21 to increase the duration
of the Anti-Icing Routine. If the anti-icing cycle does not melt
the ice, switch the air-conditioning unit to Aux Heat/Heat
Mode until the ice melts or use a hair dryer to melt the ice.
Verify the Air Sensor location. Ensure the sensor is located
out of direct sunlight and away from open doors or hatches.
Clean or replace the filter. Reset and stop the flashing by
pressing the Fan, Up, and Down buttons simultaneously.
Verify the proper condenser fan operation. Check for
blockages in the condenser air flow.
Try restarting the air conditioning unit. The installed low-
pressure switch has a ten-minute shutdown time delay that
may be in effect.
Check the air conditioning unit for a refrigerant leak. If a leak
is found, call a service technician.
Check the head pressure.
Verify the power to the unit using a multimeter.
Verify that Programmable Function 8 matches the voltage
reading to the unit with a multimeter. Adjust Programmable
Function 8 if necessary. Refer to "Programmable Functions,
Ranges, and Factory Defaults" on page 18.
Troubleshooting
27