Coleman RV rooftop air conditioner shows F7 and the heat pump or electric heat strip may not operate correctly (if equipped).

Safety: Disconnect RV power before accessing the rooftop unit or thermostat wiring.

• Verify thermostat settings: Ensure the thermostat is configured for heat pump operation if your Coleman-Mach unit is a heat pump. Incorrect configuration can cause F7.
• Check O/B wiring: Confirm the O/B (reversing valve) wire is connected at the thermostat and at the control board in the ceiling assembly.
• Inspect reversing valve coil: On the rooftop unit, locate the reversing valve and its solenoid coil. Check for loose connectors or burnt wiring.
• Coil resistance test: With power OFF, disconnect the coil leads and measure resistance. An open circuit indicates a failed coil that must be replaced.
• Board output test (technician-level): With power ON and a call for heat or cool (depending on system logic), measure voltage to the reversing valve coil. If no voltage is present and wiring is good, the control board may be defective.

Warning: Do not attempt to replace the reversing valve body yourself; this requires refrigerant recovery and professional tools.