Tumble Dryer Door Switch or Interlock Failure
The door switch (interlock) tells the control board the door is closed and safe to run. When it fails, the dryer may refuse to start even with the door firmly shut, or it may stop mid-cycle if the switch is intermittent.
Common causes
- A worn switch contact inside the door frame that no longer registers reliably
- A broken actuator tab on the door itself that fails to press the switch
- Corroded or loose wiring at the switch connector
- General age-related wear, since interlock switches see thousands of open-close cycles over a machine's life
How to check it
- Unplug the dryer and locate the door switch, typically mounted just inside the door frame on the cabinet side.
- Press the switch by hand with the door open and listen or feel for a distinct click.
- Use a multimeter to test continuity across the switch terminals as you press and release it manually.
- Inspect the wiring connector for corrosion or a loose crimp.
Fixing it
Door switches are inexpensive and typically held in place with one or two screws, with a simple plug-in wiring connector. Confirm the replacement part matches your model, since switch designs vary between brands even when they look similar.
When to call a technician
If the switch tests fine but the dryer still won't recognize the door as closed, the fault may be upstream in the control board's wiring harness, which is worth having traced by someone familiar with your model's wiring diagram.
Prevention tips
Door switches wear out from repeated use over years, so a switch that finally fails after a decade of service isn't unusual and isn't a sign of a wider problem. Keep the switch area free of lint and avoid forcing the door shut if it feels like it's resisting, since that resistance often means the latch and switch aren't aligning properly and forcing it can snap the actuator tab.
Quick questions
Can a door switch fail intermittently rather than completely? Yes — a worn switch can work sometimes and not others, which is often more frustrating to diagnose than a switch that's failed outright, since the fault won't show up every time you test it.
Is the door switch the same part as the door latch? No — the latch is the mechanical part that holds the door shut, while the switch is the electrical component that tells the control board the door is secured; both can fail independently.
Parts and repair notes
Door switches are compact, inexpensive, and among the more commonly replaced electrical parts in a tumble dryer, so this repair is typically completed quickly once diagnosed. The main variable is diagnosis time itself, since an intermittent switch fault can take longer to confirm than one that fails consistently — a technician may ask you to describe exactly when the fault tends to occur to help narrow it down faster.
Related issues to watch for
Door switch failures are sometimes triggered by a latch that isn't engaging the switch actuator precisely, so it's worth checking latch alignment even after confirming the switch itself has failed, to avoid the replacement switch wearing out prematurely from the same misalignment.