Wolf Fan-Only Cycling Without Heat

Furnace blower starts and stops repeatedly without burner ignition.

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

Fan-only mode enabled on thermostat, Control board fan test mode active, Faulty fan relay on Wolf control board, Miswired G (fan) terminal

Safety: Turn off power before adjusting wiring.

Thermostat settings: Confirm the thermostat fan setting is AUTO, not ON or CIRCULATE, if you expect normal heat cycles.
Reset control: Power cycle the furnace to exit any test modes.
Wiring check: Verify that the G wire from the thermostat is correctly connected and not shorted to R.
Control board: If the blower cycles erratically with thermostat wires removed, the Wolf control board fan relay may be defective and require replacement.

Medium 3/5

Wolf Integrated Furnace Control Board

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