Ferroli Fan Stuck On / Post-Purge Fault

Ferroli furnace fan runs continuously even when there is no call for heat.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Stuck fan relay on Ferroli PCB, Faulty flue gas sensor requiring extended purge, Incorrect wiring from external controls

Safety: Continuous fan operation is usually not dangerous but indicates a control fault.

Steps:

Check thermostat: Ensure all external controls are set to OFF and there is no call for heat.
Power reset: Turn off power for 30 seconds, then restore. If the fan starts immediately with no demand, the issue is internal.

Professional help: PCB relay testing/replacement and sensor diagnostics should be performed by a technician.

Hard 4/5

Main Control Board (PCB)

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