The short answer
A Bosch SMU-series dishwasher that will not start is usually not broken, and on this family the reason it looks broken is the panel: the controls sit on the face of the door and stay readable with the machine shut, so the panel is the first thing that reports a fault. That single fact reorders the whole check list, because it decides whether a dark machine means no power or just a closed door.
What you observe
- A single tone when the door is pushed shut — The latch is being asked to engage and is not quite making it.
- It runs the pump for a minute and stops — That is a protective drain, not a start, and it means the machine is checking its own base pan.
- The display shows a time that never counts down — A delayed start that was set and then forgotten is the commonest version of this.
- NEAR MISS - the cycle starts and stops a few minutes in — That is a fill or a heat problem rather than a start problem, and it belongs on a different page.
Likeliest causes here
- Child lock, control lock or a delayed start — Each of these makes the machine look dead or idle in a slightly different way, and all three are cleared from the panel. First on this family, and for a reason that belongs to the platform: this designation carries more lock-out modes than the ones before it.
- The supply - a switched outlet or a tripped breaker — A dishwasher is very often on a switch under the sink that somebody turned off while cleaning. Second here, and close enough behind the first to be checked in the same pass: a dark front panel here means exactly this and nothing else, which is why it leads.
- The door not quite latching — Nothing on this machine is allowed to happen until the latch confirms, and a rack that protrudes by a finger width stops it confirming. Ranked third on these models: the cheapest thing on the list to rule out.
- The cycle never actually started — A programme selected is not a programme running, and on these panels the confirmation and the selection are two different actions. Last, and the ranking is the point: obvious once the sequence is known.
- Where this ranking departs from the brand-generic page — The cause that moves is child lock, control lock or a delayed start. It leads on this family because this chassis carries a softener reservoir in the tub floor beside the filter. That is a property of the platform rather than of the brand, which is why the page above this one cannot rank it the same way.
Check in this order
- Hold the lock key until the display changes — Clear any delay while you are there, and look for a demo or showroom mode if the machine is recently installed. It leads on these models because the construction puts it within reach before anything else on the list.
- Find the switch under the sink and the breaker — A dishwasher circuit is a standard household branch circuit rated 15 A or 20 A; check both ends of it before suspecting the machine.
- Push the door firmly until it is definitely home — Then check nothing - a handle, a tall item, a rack corner - is holding it a few millimetres off.
- Select the programme, then confirm it, then close the door — On these panels the machine does not begin until the door shuts on a confirmed selection.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel - a capacitor can hold a charge after the power is off, and a machine that appears dead is not proof that it is. A dishwasher circuit is a standard household branch circuit rated 15 A or 20 A, so a breaker that trips again after being reset is reporting a fault and should not be held in.
When to call
The door, the panel, the lock-outs, the switch under the sink and the breaker are all owner ground on these models, and between them they account for most no-start calls. The line is the latch switch: a door that is definitely home and still ignored needs a meter on the switch and on the board supply.
Nearest pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
