The short answer
Water at the front of the machine is usually the door seal, the door alignment or excess suds. Water appearing under or behind it is a hose, the sump or the pump, and that means isolating the machine and pulling it out - a job worth doing carefully or handing over.
Where the water is
- A trickle down the front of the door — Seal, alignment or suds.
- Water at the plinth only during the cycle — Something under the tub; isolate the machine.
- Damp or swollen cabinet floor beside the machine — A rear leak that has been running for a while.
- Foam escaping rather than water — Wrong detergent, or washing-up liquid used by mistake.
- A puddle only after a heavy wash — Overfilling or a sump seal.
- Not this fault: standing water inside the tub — That is the drainage page.
Ranked for a built-in machine
- Door seal perished, displaced or fouled — First for front leaks, and often just needs cleaning.
- Washing-up liquid or too much detergent creating suds — Second, and the easiest to prove by changing what you use.
- Door out of alignment after cabinet or worktop work — Third, and it leaks at one corner rather than across the door.
- Inlet or drain hose connection loose — Fourth, and it is behind the machine where nobody looks.
- Sump or pump seal weeping — Fifth, and it shows as water at the plinth during the cycle.
- Tub corrosion or a crack — Last, and it usually ends the machine.
Find it in this order
- Dry everything and run one cycle while watching the door — The front half of the diagnosis is free.
- Check what detergent has been used — Washing-up liquid in a dishwasher makes a spectacular mess.
- Inspect and clean the door seal and the door edge — Debris holds a seal open at a single point.
- Isolate water and power before looking underneath — Everything past this point needs the machine out.
Owner checks
- Dry the floor and lay paper towel at the plinth and beside the machine — It shows where the water arrives first.
Tools: paper towelAbout 10 min
- Run one cycle and watch the door and the plinth — Timing and location together place most leaks.
About 90 min
- Clean the door seal and check it is seated in its channel — Grease and debris hold it off the tub.
Tools: clothAbout 15 min
- Use only dishwasher detergent and reduce the dose — It removes the suds explanation entirely.
About 10 min
- Close the water supply and switch off the breaker before pulling the machine out — Both, not one.
Tools: adjustable wrenchAbout 20 min
- Stop before removing the pump or the sump — Those need the machine on its back and are service work.
Water, cabinets and mains
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Close the water supply before disturbing any hose, and dry the floor before pulling the machine forward, because worktop-fitted machines catch on the flooring and tip. Treat a wet cabinet floor beside a dishwasher as a leak that has been running for some time.
When to call
Call when the leak is under or behind the machine rather than at the door, because that means isolating the supply, drawing the machine out from under the worktop and working around the pump. Call promptly: a slow leak into a cabinet base damages the kitchen far faster than it damages the appliance, and the repair cost rarely reflects that.
Related pages
Scope of this page
Generalized across dishwasher families under this badge; where a family-specific or model-specific page exists it is the narrower answer. Not here: seal and pump part numbers, hose specifications, tub materials and the installation details that differ by kitchen.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
