Ariston Fan Stuck On

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 control board, Faulty fan limit switch, Incorrect thermostat wiring, Control board fault

Safety: Isolate power before accessing the control compartment.

Check thermostat fan setting: Ensure the thermostat is set to AUTO, not ON.
Power cycle: Turn off power for a few minutes, then restore. If the fan starts immediately without a heat call, a relay or limit switch may be stuck.
Inspect fan limit (warm-air models): Some units use a fan/limit control that can stick. A technician should test and replace if necessary.

Medium 3/5

Control Board (PCB)

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