What the symbols on your dishwasher mean
Most lights on a dishwasher fascia are not faults. Two of them are asking to be topped up, and mistaking those for a breakdown is the commonest error here.
What it usually means
The lights on a dishwasher panel fall into three groups, and knowing which group you are looking at answers the question before you have identified the symbol.
The first group is consumables, and it accounts for most of the searches that bring people here. Every dishwasher with a built-in water softener has a salt indicator, and almost all have a rinse aid indicator, and both exist to tell you a reservoir is empty. Nothing is wrong. The salt one matters more than people think: in most of England the water is hard, the softener is what stops limescale coating the element and the inside of the machine, and it does nothing at all once the salt has run out. Use dishwasher salt specifically, because table and cooking salt carry anti-caking additives that damage the softener unit, and that is a repair rather than a refill. Rinse aid is the difference between glasses that dry clear and glasses that dry spotted, and on machines with an adjustable dose the setting is worth a look before you blame the machine.
The second group is state. A padlock is a child lock or a control lock, switched on and off by holding a button rather than by any repair. A clock or a number followed by an h is a delay start, which is why a machine can sit apparently dead for hours after you pressed go. A programme number or a duration in minutes is exactly that and nothing more. And Bosch, Siemens and Neff machines project a light onto the kitchen floor while running, so a beam that has gone out means the cycle has finished, not that anything has failed.
The third group is faults, and they look different: a tap symbol, or a letter and a number. The tap is the one worth learning because it has a single clear meaning across every make — the machine asked for water and did not get enough of it — and its causes run from a turned-off isolating valve under the sink to a blocked inlet filter, most of which you can check yourself. Anything with a letter and a number in it is a code, and the page for that code will tell you what your manufacturer actually publishes about it, which varies enormously between makes.
How to narrow it down
Work through these in order.
Is it a tap symbol?
That means water is not arriving in the quantity the machine wanted. Check the isolating valve on the pipe under the sink is fully open, then unscrew the inlet hose at the tap end and look for the small mesh filter inside the connector, which silts up over years. Both are owner checks and both are free.
Is it the salt or rinse aid indicator?
Neither is a fault; both are refill prompts. Salt goes into the reservoir in the floor of the tub under the bottom basket, and must be dishwasher salt rather than any other kind. Rinse aid goes into a small capped well inside the door. A machine that has run without salt for years in a hard water area will also need descaling.
Is it a padlock?
A child lock or control lock, which freezes the buttons so a cycle cannot be interrupted or started by accident. It is cleared by holding one button — often the one marked with the padlock — for several seconds. Some machines also lock the door itself during a hot programme, and that releases on its own as it cools.
Is it a clock, or a number with an h after it?
A delay start, and the number is how many hours until the machine begins. It is the answer to a dishwasher that seems to have died the moment you closed the door, and it is cancelled either by pressing the delay button round to zero or by switching the machine off and on again.
Has a light on the floor gone out?
On Bosch, Siemens and Neff machines a beam projected onto the floor is how a very quiet appliance tells you it is running. It changes or goes out when the programme ends. A dishwasher with no light on the floor and a closed door has almost certainly finished rather than stopped.
Is it a letter with a number?
Then it is a fault code and worth looking up rather than guessing at, because the same-looking code means different things on different makes and manufacturers publish very different amounts about them. Some have a named part and a full owner procedure behind them; others have nothing published at all.
Are all the lights flashing at once?
On machines with no display, several lights flashing together, or a pattern of beeps, is how a fault is reported — and the number of flashes or beeps is the code. The manual for your model maps them, and it is worth counting carefully, because two flashes and three mean entirely different things.
Codes commonly shown with this
- E27BoschThe mains voltage is too low. Bosch state plainly that this is not a fault on the appliance — you want an electrician, not an appliance engineer.Get it checked
- F52MieleA sensor has detected too much foam and stopped the programme. Nothing is broken — the machine is protecting itself from suds.Usually simple to fix
- F86MieleThe salt reservoir flap in the door is not closed. On Miele machines with the salt container in the inner door, a lid left open after a refill stops the programme. Ten seconds to fix.Usually simple to fix
- IELGWater inlet problem. It is IE with a letter I, not 1E — the washing machine convention does not apply here.Get it checked
- 4CSamsungWater supply check. Samsung’s checks are the valve, the supply and a frozen or clogged inlet, and their manuals give the pressure and temperature the supply has to meet.Get it checked
- No water supplyLamonaE:02, with the tap symbol lit. Howdens give two checks and, in two of the four manuals read, the only reset they publish — press start twice.Get it checked
When it is urgent
Take care
What it costs
Typical repair cost
£0–£180
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Get an engineer to look at this
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.