Dometic RV air conditioner fault codes
RV roof air conditioners and their thermostats show codes for communication faults, sensor failures, or freeze protection.
How to read the code
Codes usually appear on the wall thermostat. Note whether the code clears when you cycle power, which often points to a communication issue.
All documented codes
E0 / EA / EE warning
Electronics and drive faults on the FreshJet inverter board. E0 = communication failure be… E1 warning
The thermostat has lost its communication link with the air conditioner/heat pump control … E2 warning
The indoor (return-air) temperature sensor is reading open-circuit or out of range. The sy… E3 warning
The indoor (return-air) temperature sensor is reading as shorted. As with E2, all heating … E4 warning
The outdoor temperature sensor (fitted on select heat-pump models) is reading open-circuit… E5 warning
The freeze sensor is reading open-circuit or out of range (documented on the Single Zone L… E6 warning
The CCC2 thermostat reads an open circuit on the optional humidity sensor (only fitted on … E7 warning
The CCC2 has lost 120 VAC line power to all of the air conditioner power module boards, so… E8 warning
Invalid zone configuration: the heat pump and electric heat strip DIP switches are both se… E9 warning
Invalid zone configuration: the dehumidifier DIP switch and either the heat pump or heat s… EL warning
LIN-BUS / CI-BUS communication failure. The air conditioner has lost the data-bus link it … P0 warning
The inverter control module (IPM) has detected an over-temperature or over-current conditi… P1 warning
Under-voltage protection. The unit has detected the incoming supply voltage is too low to … P2 / P3 warning
P2 is AC over-current protection (the unit is drawing more current than allowed). P3 is ov… P4 / P5 / P6 / P7 warning
Refrigerant-circuit temperature protections. P4 = discharge tube (compressor outlet) overh… P9 warning
Compressor drive abnormal, or the compressor fails to start. The inverter drive cannot bri…
Electronics and drive faults on the FreshJet inverter board. E0 = communication failure be… E1 warning
The thermostat has lost its communication link with the air conditioner/heat pump control … E2 warning
The indoor (return-air) temperature sensor is reading open-circuit or out of range. The sy… E3 warning
The indoor (return-air) temperature sensor is reading as shorted. As with E2, all heating … E4 warning
The outdoor temperature sensor (fitted on select heat-pump models) is reading open-circuit… E5 warning
The freeze sensor is reading open-circuit or out of range (documented on the Single Zone L… E6 warning
The CCC2 thermostat reads an open circuit on the optional humidity sensor (only fitted on … E7 warning
The CCC2 has lost 120 VAC line power to all of the air conditioner power module boards, so… E8 warning
Invalid zone configuration: the heat pump and electric heat strip DIP switches are both se… E9 warning
Invalid zone configuration: the dehumidifier DIP switch and either the heat pump or heat s… EL warning
LIN-BUS / CI-BUS communication failure. The air conditioner has lost the data-bus link it … P0 warning
The inverter control module (IPM) has detected an over-temperature or over-current conditi… P1 warning
Under-voltage protection. The unit has detected the incoming supply voltage is too low to … P2 / P3 warning
P2 is AC over-current protection (the unit is drawing more current than allowed). P3 is ov… P4 / P5 / P6 / P7 warning
Refrigerant-circuit temperature protections. P4 = discharge tube (compressor outlet) overh… P9 warning
Compressor drive abnormal, or the compressor fails to start. The inverter drive cannot bri…