Rittal air conditioner error codes

ACs’ sensors can help you find the cause of a malfunction. Systems notify users through error codes. They speed up the search time. Errors resulting from compressor issues and lack of Freon are considered the most serious ones and likely to affect a devices further operability.

Display screenSystem messagePossible causeMeasures to rectify the fault
A01Enclosure door openDoor open or door limit switch incorrectly positionedClose door, position door limit switch correctly, check connection if necessary
A02Internal temperature of enclosure too highCooling capacity inadequate/unit undersized. Error as a consequence of messages A03 to A17.Check cooling capacity
A03Filter monitoringFilter mat soiledClean or replace; reset the e-Comfort controller
A04Ambient temperature too high/too lowAmbient temperature outside of admissible operating range (+10?C to +60?C)Raise or lower the ambient temperature (e.g. heat or ventilate the room)
A05Icing hazardOperational display in case of icing hazard. Evaporator coil fan may be mechanically blocked, defective, or cold air outlet obstructed.Set the enclosure interior temperature to a higher value. Check the evaporator fan; release or exchange if necessary.
A06PSA pressure-operated switchAmbient temperature too highLower the ambient temperature; reset the e-Comfort controller
Condenser soiledClean the condenser; reset the e-Comfort controller
Filter mat soiledClean or replace; reset the e-Comfort controller
Condenser fan defectiveReplace; reset the e-Comfort controller
E-valve defectiveHave the sensor repaired by a refrigeration engineer; reset the e-Comfort controller
PSA pressure-operated switch defectiveHave the switch replaced by a refrigeration engineer; reset the e-Comfort controller
A07Evaporator coilLack of coolant; sensor in front of or behind condenser defective.Have the sensor repaired by a refrigeration engineer; reset the e-Comfort controller
A08Condensate warningCondensate discharge kinked or blockedCheck condensate discharge; repair any kinks or blockages in the hose as necessary
Only in units with optional condensate evaporationCheck the evaporation unit, exchange if necessary
A09Condenser fanBlocked or defectiveClear the blockage; replace if necessary
A10Evaporator fanBlocked or defective
A11CompressorCompressor overloaded (internal winding protection)No action required; unit switches back on automatically.
Defective (check by measuring the winding resistance)Exchange by refrigeration engineer
A12Condenser temperature sensorOpen or short-circuitReplace
A13Ambient temperature sensor
A14Icing temperature sensor
A15Condensate warning temperature sensor
A16Internal temperature sensor
A17Phase monitoringFor three-phase devices only: Incorrect rotary field/phase absentExchange two phases
A18EPROM errorNew board obstructedSoftware update needed (only following board installation with more recent software): Enter the programming level with Code 22; press button 1 and confirm with “Set” until “Acc" appears. Next, disconnect the unit from the mains and reconnect.
A19LAN/Master-SlaveMaster and slave not connectedCheck setting and/or cable
A20Voltage dropError display not shownEvent is stored in the log file
EODisplay messageConnection problem between the display and the controller boardReset: Switch power supply off, then switch on again after approx. 2 sec.
Cable defective; connection looseExchange the boards
b07Cooling circuit leakSensor B3 and B4 mixed upCorrect sensor position
rStResetManual device reset required
OLOverloadAmbient parameters or heat loss outside of the applicable limits