Separate the fault before troubleshooting it: is the machine completely dead, or does it have power but refuse to begin? A dead machine is a power problem — socket, plug or breaker. A machine with lights or a display that will not start is almost always the door not latching properly, a delay setting left on, or a child lock enabled.
Dead, or powered but not starting?
- Completely dead — no lights, no display, nothing happens when you press start. The machine is not receiving power.
- Powered but inert — lights or a display work, buttons respond, but pressing start does nothing, or the machine begins then immediately stops.
If the machine is completely dead
Switch off at the wall before checking the plug, cable or the isolator switch some kitchens fit under the sink. Do not plug back in if you see scorching or melted plastic — that needs an electrician.
- Check the socket and any isolator switch
Many dishwashers are wired through a fused connection unit or a switched socket under the sink rather than a visible plug. Confirm that switch is on — it gets knocked off during other work under the sink more often than people expect.
- Test the breaker
Look at the consumer unit. Switch the relevant breaker fully off and back on rather than just glancing at it, since a partially tripped breaker can look on while still cutting power.
- Check the door is fully closed
Some machines show absolutely no sign of life at all if the door is not latched, which can look exactly like a power fault.
If it has power but will not begin
- Close the door firmly
Push it shut until you hear or feel the latch engage. A door that looks closed but has not fully latched is the single most common reason a powered machine will not start.
- Check for a delay start
If the display shows a countdown or a small clock icon, a delayed start has been set. Cancel it and start the cycle directly.
- Check for a child or control lock
Look for a padlock or key symbol. It is usually cleared by holding two buttons together for a few seconds — check the control panel or manual for the exact combination on your model.
- Confirm the water supply is on
Some machines will not proceed past the first fill if the water valve behind them is closed, and this can present as the machine simply doing nothing after you press start.
- Reset the machine
Switch off at the wall for a full minute, then power back up and try a short cycle. This clears a latched fault the control board may be holding even after the underlying cause has gone.
- Check the water level and float switch
Some models refuse to start if they detect too much water already sitting in the base — often connected to the same float switch used for flood protection. If you recently had a leak or standing water, clear it fully and dry the base before trying again.
Common causes
| Cause | How likely | Which symptom |
|---|---|---|
| Isolator switch or fused spur off | Common | Completely dead |
| Tripped breaker | Common | Completely dead |
| Door not fully latched | Very common | Powered, will not begin |
| Delay start set | Common | Countdown showing on the display |
| Child lock enabled | Common | Buttons unresponsive, padlock symbol |
| Water supply closed | Occasional | Starts then stalls at the fill stage |
| Float switch triggered by standing water | Occasional | Recent leak; machine refuses to start |
| Door latch or switch mechanism failed | Occasional | Door closes properly, machine still will not start |
| Control board fault | Uncommon | Everything else checks out |
When to call a professional
Call an electrician if the isolator and breaker are confirmed fine but the machine is still completely dead, or if you find any scorching or damage at the connection. Call an appliance engineer if the door latches correctly, the water is on, and there is no standing water, but the machine still refuses to start — that points at the door latch switch or the control board, both of which sit next to live components inside the door frame or the base.
Stop and call a qualified appliance technician or electrician if you find scorched or melted wiring, smell burning, see water that has reached electrical components, or if the fault returns immediately after a repair. Never bypass a safety device — thermal fuses, door interlocks and flood switches fail for a reason, and defeating one converts a broken appliance into a fire or flood risk.
