26
EN
Troubleshooting
Universal Air Conditioning Unit
Problem
Possible Reason
Possible Solution
There is no cooling or
heating.
The temperature set point is satisfied.
Lower or raise the set point using the Q3 control.
The condenser air flow is obstructed.
Check for any obstructions at the condenser. free the
condenser of any obstructions and clean the condenser if
necessary.
There has been a loss of refrigerant gas.
Check the air conditioning unit for refrigerant leaks. If leaks
are found, call a service technician for repair.
The outside temperature is too high for
efficient cooling.
The outside air temperature will directly affect the air
conditioning unit’s efficiency. This air conditioning unit can
effectively cool temperatures up to 95 °F (35 °C).
The evaporator coil is iced (in cooling).
Refer to “Troubleshooting” on page 25.
The fan is not running.
• Refer to “Digital-Controls Troubleshooting” on page 26.
• Check the capacitor, connections, and motor.
• Call a qualified Dometic service technician.
The control is in fan-only mode.
Set the system for Cool Mode or for Aux Heat/Heat Mode.
The digital control is programmed for
Cool or Aux Heat/Heat only.
Refer to “Digital-Controls Troubleshooting” on page 26.
The high-pressure switch is open (in
cooling) due to improper air flow.
The intake may be plugged. Verify the condenser fan
operation.
The compressor’s thermal overload is
open due to lack of air flow though the
condenser.
Allow the compressor to cool. Turn the system off for a while
(it may take up to three hours to reset the thermal overload).
10 .2 Digital-Controls Troubleshooting
WARNING: ELECTRICAL SHOCK HAZARD .
The control board operates at 115 VAC or 230 VAC.
Ensure the power is off before removing the cover
of the control box. Failure to obey this warning
could result in death or serious injury.
Use this table to troubleshoot problems with the Q3
control. Refer also to “General System Troubleshooting”
on page 25.
Problem
Possible Reason
Possible Solution
The evaporator fan is
not running when the
Compressor shuts off.
The Q3 control is programmed for fan
cycling with the compressor.
Change Programmable Function 7. Refer to “Programmable
Functions, Ranges, and Factory Defaults” on page 18.
The evaporator fan runs
continuously at various
speeds.
The Q3 control is programmed for
continuous operation which is the
preferred factory default.
Change Programmable Function 7. Refer to “Programmable
Functions, Ranges, and Factory Defaults” on page 18.
The evaporator fan is
not running but the
Compressor is running.
The circuit board failed.
Send for repair or call a local service technician.
The Q3 control
display panel is not
illuminated.
There is no power to the Q3 control.
Turn the circuit breaker on.
Check the control and temperature
sensor cables and connections.
Replace the digital or temperature sensor cables if necessary.
The Q3 control failed.
Contact an authorized Dometic servicing dealer for
replacing the Q3 control.
