Dometic rooftop air conditioner · 1 model line
Dometic rooftop air conditioner code P3: Overvoltage protection
Dometic documentation lists P3 as “Overvoltage protection”.
What code P3 means by model
| Model line | What the manufacturer says | Source |
|---|---|---|
| Dometic FreshJet Series 4 / Series 7 (FJX) | The Dometic FreshJet FJX operating manual lists P3 as overvoltage protection. | Dometic FreshJet Series 4, FreshJet Series 7 Operating Manual |
What you can safely check
- Record P3, selected mode, setpoint, and whether the code appeared after a campsite power change.
- Ask campsite management whether campsite power is sufficient and stable for air conditioner operation.
- Stop FreshJet operation from normal controls if the code returns.
Stop and call a technician for
- Overvoltage protection, current sensor, converter, internal electrical protection, and rooftop compartment diagnosis should be handled by authorized Dometic service or qualified RV HVAC personnel.
Disconnect power before any FreshJet service. Refrigerant-circuit, sealed-system, sensor, fan, drive, electrical protection, roof seal, and internal component work is for authorized Dometic service or qualified RV HVAC personnel.
Write this down before you call
- Full FreshJet model and serial number from the data label
- Wall control or display code photo
- Shore-power or campsite voltage context and active loads
- Recent service history and prior recurring codes
Other codes on Dometic FreshJet Series 4 / Series 7 air conditioners
Full table: Dometic FreshJet Series 4 / Series 7 air conditioners
- P0 Over temperature or over current on the IPM module
- P1 Under voltage protection
- P2 Unit AC over-current protection
- P4 Discharge tube overheat protection
- P5 Evaporator coil protection in cooling mode
- P6 Condenser coil protection in cooling mode
- P7 Evaporator coil protection in heating mode
- P9 Compressor drive abnormal or compressor does not start
- E0 Communication failure
- E1 Room temperature sensor fault
- E2 Evaporator coil temperature sensor fault
- E3 Condenser coil temperature sensor fault
- E7 Outdoor temperature sensor failure
- E8 Discharge tube temperature sensor failure
- E9 Compressor drive or IPM module fault
- EA Current sensor fault
- EE Outdoor EEPROM fault
- EL LIN-BUS/CI-BUS communication failure
Related troubleshooting guides
- Dometic FreshJet FJX constantly switches itself off
- Dometic FreshJet FJX low air output
- Dometic FreshJet FJX not cooling within temperature limits
- Dometic FreshJet FJX not heating within temperature limits
- Dometic FreshJet FJX voltage protection and campsite power
- Dometic FreshJet FJX water enters the vehicle
- RV appliance low-voltage warning