Dishwasher leaking onto the kitchen floor

What it usually means

Do this before reading any further: turn off the tap feeding the dishwasher, usually under the sink and often a small lever valve on the flexible hose, and switch the machine off at the wall. A dishwasher is plumbed into the mains and normally runs unattended, which is why a leak here does more damage than a leak from almost any other appliance in the house.

Once it is safe, the useful question is where the water is coming from, and the puddle is a poor guide. An integrated machine sits in a sealed box under a worktop, so water follows the path of least resistance and appears at the front long after it started somewhere at the back. Water on the floor at the front of the plinth can equally well be a split inlet hose behind the machine.

Most leaks come from one of five places. The door seal, which perishes and goes hard with age. The door itself, if the machine is not level, so water sits against one side of the seal instead of being held evenly. The inlet hose, particularly at the connections. The waste hose, especially where it clips into the sink waste. Or the tub and pump, which is the most serious and the least common.

There is one specific cause worth ruling out first because it is free and extremely common: too much detergent, or the wrong detergent. Washing-up liquid in a dishwasher produces an enormous volume of foam, and foam escapes past a door seal that handles water perfectly well. If anyone has put washing-up liquid in the machine, that is almost certainly your answer and there is nothing wrong with the appliance.

Also worth knowing: most dishwashers have an anti-flood system with a float in a base tray under the tub. If that has triggered, the machine will show a code and refuse to run. That is the system working. The widely shared advice to tip the machine over and drain the tray clears the code without touching the leak, and it disables the protection that is currently containing the problem.