Troubleshooting guide
Onan generator exhaust smell, CO detector, or ventilation shutdown
Cummins Onan quick-start and handbook safety guidance treat carbon monoxide, exhaust leaks, blocked airflow, and unsafe ventilation as shut-down conditions that belong with qualified generator service.
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
- Shut the generator down immediately if a CO detector alarms, exhaust odor enters the RV, or exhaust damage is visible.
- Move people to fresh air and do not sleep with the generator running in unsafe ventilation conditions.
- Look only for obvious external blockage around the generator intake or exhaust outlet from safe ground access.
- Call qualified generator service before running again if any exhaust leak, CO detector event, soot, or ventilation concern remains.
Code tables for these appliances
- Cummins Onan QG gasoline generators (HGJAA, HGJAB, HGJBB) 32 codes
- Cummins Onan QG 2800i / 2500i LP inverter generators 29 codes
- Cummins Onan QG 2800 KV generators 4 codes
- Cummins Onan QG 4000 / 3600 LP generators 19 codes
- Cummins Onan QG 7000i dual-fuel inverter generators 25 codes
- Cummins Onan Quiet Diesel 5000-12500 generators 23 codes
- Cummins Onan Quiet Diesel 3200 generators 14 codes