Do this first
- Electrics before water. Switch the machine off at the socket or the fused spur, usually in the adjacent cupboard, and pull the plug if you can do it with dry hands and without standing in water. If not, switch the circuit off at the consumer unit.
- Close the inlet valve under the sink. It is normally a small lever or screwdriver-slot valve on the branch feeding the machine.
- Cancel the cycle and let it drain if it will, then open the door and sponge out any standing water in the base.
- Look before you pull it out. Note whether the water is at the front under the door, at the back, or spreading from under the middle, and note where in the cycle it appeared.
- Check the cupboard next door and the plinth line. An integrated dishwasher leaks sideways into the carcass of the neighbouring unit before it reaches the room.
- Photograph it before mopping, particularly if you are above another flat.
Mid-cycle puddle, or water before you started
Timing separates the two families here, and they have different owners.
| When it appears | Cause | Whose job |
|---|---|---|
| Part-way through a cycle, at the front under the door | Door seal perished, or the door is not closing squarely | Appliance engineer, or a new seal |
| Part-way through a cycle, from under the machine | Internal hose clip, sump or pump seal | Appliance engineer |
| Before the machine has been started, or overnight | Inlet valve or the connection under the sink: mains pressure, leaking continuously | Plumbing |
| Only as it pumps out | Waste hose, its clip at the trap spigot, or a restricted waste | Plumbing |
| Foam escaping the door | Washing-up liquid used instead of dishwasher detergent | Nobody. Rinse it out. |
The dangerous version is the one that leaks when the machine is not running, because it is at mains pressure and it does not stop. An integrated dishwasher sits in a sealed run of units, so a slow inlet leak fills the void behind the plinth, soaks the carcass of the units either side, and comes out at the front of the kitchen weeks later as a lifting floor. By the time it is visible it has usually been running for a long time, which is also why so many of them show up first as a stain on a downstairs ceiling.
The other quiet cause is the waste. A hose pushed too far into the trap spigot, or a waste branch with a poor fall, makes the machine work against back-pressure, which pushes water out at the weakest connection. Correcting that is what stops it recurring. If other things under the sink are wet too, read a leaking pipe under the sink.
What the repair involves
On the supply side, the inlet valve and the flexible connection are replaced with new seals and the joint is tested under full pressure with the machine reconnected. On the waste side, the hose, the clip, the trap spigot and the standpipe or branch arrangement are corrected so the fall and the height are right rather than simply refitting what was there.
Then the kitchen. This is the part that decides the cost of a dishwasher leak. Swollen carcass panels, a delaminated plinth, a lifting floor and a soaked substrate all get lifted, dried and reinstated, and where water has gone through to a room below, the ceiling is cut back, dried, reboarded, skimmed and painted. That is the whole of water leak repair here, and the rate is on the pricing page.
When it is not us
- Foam everywhere. Washing-up liquid in the dispenser. Run an empty rinse cycle and use the right detergent.
- A perished door seal, a failed sump or a pump fault. Appliance engineer. On a machine in warranty, the manufacturer's.
- Water only when overloaded or when a tall item blocks the door. Load it differently.
- A blocked filter in the base making it back up. Take the filter out, clean it, refit. Two minutes, and it is routine maintenance rather than a fault.
- The machine is old and this is one of several faults. Price the repair against a replacement before spending anything.
- You rent and the appliance is the landlord's. Report it in writing, and be clear about whether it is the machine or the plumbing, because those are two different responsibilities.