Washer-dryer combo displays F40 and will not start or may stop mid-cycle.

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

Faulty temperature control circuit, wiring issue between sensor and control, main control board failure

Safety first: Unplug the unit before accessing controls or sensors.

Step-by-step checks:

1. Verify water supply temperature: Ensure hot and cold hoses are not reversed and that both supplies are present.
2. Inspect temperature sensors: Check NTC sensors on the tub and dryer duct for secure connections and correct resistance.
3. Wiring inspection: Trace sensor wiring back to the control board and repair any damage.
4. Control board: If sensors and wiring are good, the ATC function on the control board may be defective and require replacement.

Hard 4/5

Main Control Board (CCU)

Check Price on Amazon

We may earn a commission from links on this page.