25
EN
Universal Air Conditioning Unit
Troubleshooting
10 Troubleshooting
Before you call for service, review this list. It may save you
time and expense. If you need service after trying these
procedures, call your nearest Dometic dealer.
10 .1 General System
Troubleshooting
This list contains common occurrences that are not a
result of defective workmanship or materials.
Problem
Possible Reason
Possible Solution
The system will not
start.
The air conditioner circuit breaker is off.
Turn the circuit breaker on at the panel.
The Q3 control is not turned on.
Press the power button on the Q3 control.
The system runs
continuously.
The set point temperature is improperly
set. It is either too low for cooling or too
high for heating.
Raise or lower the set point temperature.
The door is open.
Close the door.
The air sensor is in the improper location.
Refer to “Digital-Controls Troubleshooting” on page 26.
The outside temperature is too high for
efficient cooling.
The outside air temperature will directly affect the air
conditioning unit’s cooling efficiency. This air conditioning
unit can effectively cool outside air temperatures up to
95 °F (35 °C). It will operate at higher outside temperatures
however, the cooling capacity will be reduced.
There is low airflow
through the system.
The airflow through the evaporator is
blocked.
Inspect for and remove any obstructions in the return-air
stream.
Clean the return-air filter and grille.
Check for crushed or restricted ducting. The ducting must
be straight, smooth, and as taut as possible.
The fan coil is iced.
See below.
The fan speed is set to manual low.
If the fan speed is set to manual low, press and release
the Fan button until the desired fan speed and airflow are
reached. If you want automatic fan speed control, press and
release the Fan button until the letter “A” displays.
The fan is not running.
Refer to “Digital-Controls Troubleshooting” on page 26 .
The evaporator coil is
iced.
The Q3 control set point is too low.
Raise the set point.
There is improper airflow through the
evaporator.
Remove any obstructions in the return-air stream. Clean the
return-air filter and grille.
Check for crushed or restricted ducting. The ducting must
be straight, smooth, and as taught as possible. Refer to
“Digital-Controls Troubleshooting” on page 26 for
reprogramming options.
The supply air is short-cycling.
Redirect the supply air so that it is not blowing into the
return-air stream.
Seal any air leaks that may be present in the ducting.
The humidity level is too high.
Close the hatches and the doors.
When all else fails.
Switch the air-conditioning unit to Aux Heat/Heat until the
ice melts or use a hair dryer to melt the ice.
