Troubleshooting guide
Coleman-Mach fan runs but compressor does not start
Coleman-Mach Mach 8 service guidance lists fan runs/no compressor as a qualified-service condition that can involve insufficient voltage, thermostat, capacitors, relay, overload, freeze switch, compressor, or sealed system faults.
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
- Confirm thermostat mode, setpoint, fan setting, and any built-in short-cycle delay from normal controls.
- Record whether the indoor fan runs, whether the compressor ever starts, and whether freeze shutdown happened first.
- Stop repeated retries if the fan runs but cooling never starts.
- Use qualified RV HVAC service for electrical parts, sealed cooling circuit, or repeated no-compressor operation.