Troubleshooting guide
RV rooftop air conditioner is not cooling enough
Use this when a Furrion, Dometic, or Coleman-Mach rooftop air conditioner runs but does not cool well, switches off on freeze protection, or has blocked airflow symptoms.
Use this atlas to identify likely meaning and prepare for service. Shut off power, LP gas, fuel, or water when a listed appliance condition involves flame, gas smell, exhaust, generator shutdown, high temperature, moving jacks/slides, refrigerant, 120 VAC, control boards, repeated ignition failure, or a persistent lockout. Call the appliance maker, RV dealer, or a qualified RV technician for repair.
Owner-safe checklist
- Clean or replace return-air filters if the owner manual allows it.
- Confirm cooling mode, lower set temperature, and open supply nozzles or vents.
- Remove visible leaves or dirt from exterior grilles only from normal safe access.
- Record whether the compressor delay, freeze sensor, or fan state changed before calling service.
Related fault codes
- Dometic thermostat code E5
- Dometic rooftop air conditioner code P4: Discharge tube overheat protection
- Dometic rooftop air conditioner code P5: Evaporator coil protection in cooling mode
- Dometic rooftop air conditioner code P6: Condenser coil protection in cooling mode
- Dometic rooftop air conditioner code P9: Compressor drive abnormal or compressor does not start
- Dometic rooftop air conditioner code E2: Evaporator coil temperature sensor fault
- Dometic rooftop air conditioner code E3: Condenser coil temperature sensor fault
- Dometic rooftop air conditioner code E9: Compressor drive or IPM module fault
Official sources
FurrionFurrion Rooftop HVAC Units Troubleshooting and Service ManualFurrionFurrion Rooftop Air Conditioner with Manual Control User ManualColeman-MachColeman-Mach Frequently Asked QuestionsColeman-MachColeman-Mach Cooling Performance WorksheetColeman-MachColeman-Mach Rooftop Air Conditioner Operation and Maintenance InstructionsColeman-MachColeman-Mach ComfortGuard Cab Air System Service ManualColeman-MachColeman-Mach 6633 Series Package Air Conditioner Service ManualDometicDometic Comfort Control Center 2 Thermostat Operating InstructionsDometicDometic Single Zone LCD Thermostat Operating InstructionsDometicDometic FreshJet Series 4, FreshJet Series 7 Operating ManualDometicDometic 3316420.XXX Bluetooth CT Thermostat Operating InstructionsDometicDometic Brisk Air Conditioner Return-Air Filter Efficiency Support
Plus 12 more official sources.