The short answer
Before suspecting the control, establish three things: that the door latch has registered closed, that the machine has power, and that a delay-start or a child lock is not quietly holding the programme. Between them they explain most no-starts. On a B-Flasche dishwasher the order below is what makes this page worth reading — the causes are ranked for this kind of machine, not listed alphabetically.
The symptoms, and the near misses
- Lights are on but pressing start does nothing — Power and control are fine, so the machine is waiting for a condition — usually the latch.
- The door will not latch, or the latch feels loose — The switch inside the latch has to make before anything else happens, and it reports nothing when it does not.
- A delayed-start indicator is lit — The machine is doing exactly what it was told, several hours from now.
- The panel is completely dark — That moves the diagnosis to the supply, the plug and the door switch that cuts power on some designs.
- NEAR MISS — it starts and stops within a minute — A start-then-abort is a fill or a drain fault, and it belongs on the cycle page.
What it usually turns out to be
- Door latch or latch switch not making — First on this appliance class by a clear margin. The latch takes the full force of the door being pushed shut, the plastic hook wears, and a latch that looks closed can sit a millimetre short of the switch.
- Control locked, delayed or in a set mode — Second, and it costs nothing to rule out: child lock, delay start and demonstration mode all present as a machine that ignores the start button entirely.
- No power at the supply — Third. Dishwashers are often on a switched spur behind a cupboard door, and the switch gets knocked off during a kitchen tidy without anyone noticing.
- Water supply valve closed — Fourth. Some machines will not begin a cycle at all if they cannot confirm a fill, and the isolating valve under the sink is the usual reason.
The diagnostic order
- Look at the panel before touching anything — Lit versus dark decides whether this is a supply problem or a latch problem, and it takes one second.
- Open and close the door firmly and listen for the latch — A positive click means it made. A soft, vague close means it did not, which is the answer.
- Check the isolating valve under the sink — A quarter-turn valve left closed after plumbing work stops the machine before it starts.
What an owner can safely check
- Check the spur switch and the breaker — Find the switch in the cupboard or on the wall above the counter and confirm it is on. This is a genuinely common cause.
About 10 min
- Cancel any programme and clear delay or lock modes — Hold the cancel or start button as the panel legend indicates until the display clears, then look for a lock symbol.
About 10 min
- Close the door deliberately against the frame — Push at the latch height rather than the corner. A door pushed at the top can flex just enough to miss the switch.
About 5 min
- Inspect the latch hook and the strike for wear — Look for a rounded hook, a cracked housing or food debris in the strike. All three are visible.
Tools: flashlightAbout 15 min
- Open the isolating valve fully — Under the sink, usually a small lever or a screw-down valve on the machine feed.
About 10 min
- STOP before opening the door panel to test the switch — The latch switch is wired into the mains side inside the door skin.
Power, water and the limits of owner work
Safety
Turn the circuit off and confirm it, then close the supply valve. Anything you drain will come out faster than expected, so have a shallow tray ready. If water has reached the control board or the motor, stop there and call: a dried-out board can work for a week and fail closed afterwards.
The line between a fix and a call
Call when the supply is confirmed live, the controls are cleared and the door still will not bring the machine to life — at that stage it is the latch switch, the harness through the door hinge or the board, and the hinge harness in particular needs the door skin off to inspect. If the door has been slammed or forced, say so: a distorted door or a dropped hinge changes how the latch meets the strike and it will not be fixed by a new switch.
Related pages for this machine
Scope of this page
A note on scope. This page generalizes across B-Flasche dishwasher families rather than naming one, so nothing on it depends on a model number and nothing on it should be read as a service-manual figure. The family- and model-specific pages beneath this one carry that level of detail; they are linked here, and if one of them names your unit it is the more specific — and more useful — answer.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
