In short
When a Bosch WAT machine does nothing, start at the socket and the door rather than at the control board. Those two cost nothing to check.
What you observe
- A delay-start time is counting down — The machine is doing exactly what it was asked. It is worth checking before anything is opened.
- The drum hums but does not turn — Power is reaching the motor and something is stopping the drum, so this is a jam or a motor fault rather than a no-start.
- It starts only after being switched off and on — A control that needs a power cycle to accept a start is a real fault, but an intermittent one rather than a dead machine.
- The machine beeps when start is pressed and then stops — An input was accepted and a check failed straight afterwards, which usually means a lock or a level condition.
- A padlock or key symbol is showing — Child lock is engaged. It is designed to be non-obvious and it stops every input until it is cleared.
Likeliest causes first
- Child lock or delay start engaged — Ranks high because it produces an apparently dead machine with nothing wrong, and because it is easy to set by accident.
- No supply at the socket — Second and free to test: a tripped breaker, a failed socket or a plug that has worked loose behind the machine.
- Water not arriving so the first gate never passes — The machine accepts the start, waits for its fill, and appears to be doing nothing at all. Closed taps are the usual reason.
- Programme not actually started — On machines with a separate selection and start step it is common to leave a cycle selected and never started, especially after a power interruption.
What to check first, second, third
- Switch off at the wall for a minute and try again — Clears a control that has hung after a power interruption, and a machine that then runs has told you the fault was transient.
- Test the socket with a lamp or another appliance — It separates the dead-machine branch from the waiting-machine branch instantly, and it needs nothing you do not already own.
- Press the door firmly until it latches and listen for the lock — The lock is the first gate the machine checks.
- Listen for the lock click with the door held closed — A lock that never clicks with a properly closed door has earned suspicion; one that clicks moves the diagnosis downstream.
Power down first
Safety
Disconnect power and close the inlet taps before starting. A machine that has stopped mid-cycle may still be holding a tub full of water, and that water leaves through the drain filter whether you are ready for it or not.
Models in the WAT family
Reference| Model number | Family key |
|---|---|
| WAT28400UC | bosch:washer:wat |
| WAT28401UC | bosch:washer:wat |
| WAT28402UC | bosch:washer:wat |
Where the owner fix ends
Stop and call if the machine has already been part-dismantled and will not go back to a known state. A half-assembled drum machine is the one situation where a service call actually gets cheaper by being made earlier.
