The short answer
On a built-in machine of this age the door seal has taken every knock from loading for decades, and it is where the water usually gets out. Ranked first on this platform: The door seal. The checks below follow that ranking, and the first of them need no tools and no panel removed.
What you observe
- Water at the front of the machine while it runs, and a dry floor at rest — Leaking only while running is a running-water path.
- A burst of water at the drain phase and nothing at other times — A leak tied to the pump-out is the drain path.
- The floor is wet even after the machine has been unused for a day — Water with the machine idle is water from the pressurised side.
- NEAR MISS — a puddle only after a very foamy cycle — Foam escaping the door is a detergent problem rather than a leak, and washing-up liquid in the dispenser is the usual reason.
Causes, most likely first on this platform
- The door seal — The seal runs round the door and takes every knock from loading. It ranks first on this platform because the seal runs round the door and is perished at the corners on most machines of this vintage, so water escapes during the wash only — which is why the puddle appears part way through and never when the machine is idle.
- The drain hose or its connection — The drain hose carries water only while the machine pumps, so its leaks are intermittent and easy to blame on something else. It ranks second here because a cabinet of this vintage has wear on everything at once, which changes the ranking: the parts that wear are far more likely than the parts that break.
- The fill connection — The inlet fitting is pressurised all the time. It comes third in the order — a genuine cause here, behind the ones above it on frequency alone.
- The tub, a seam or a component behind the panel — A leak from inside the cabinet — a heater seal, a pump housing or a corroded seam — reaches the floor from the centre or the back. It sits fourth because the causes above it account for more of these cases, not because it is unlikely.
Check in this order, and why
- Run a finger round the whole seal and look for splits, hardening and debris — Two minutes with a torch and it finds most door leaks. It leads because it tests the top-ranked cause.
- Lay dry paper along the hose run and start a drain — The first sheet to get wet names the spot. Tests the second-ranked cause.
- Shut the valve, dry everything, and look again an hour later — It separates pressurised from cycle-driven leaks definitively. Tests the third-ranked cause.
What an owner can safely check
- Clean the seal and its channel, and check the door closes evenly at top and bottom — A door that is not square loads one part of the seal and not the rest.
Tools: cloth, torchAbout 20 min
- Dry everything, lay paper along the hose, and run a short cycle to the drain step — Check the connection at the waste as well as at the machine.
Tools: clothAbout 20 min
- STOP here if the next step needs a meter on live terminals or a sealed panel off — That is where an owner check ends. Write down what each check showed and hand it to the technician.
Before you start tracing it
Safety
Unplug the machine or switch off its breaker before removing any panel, and close the supply valve. The fill connection is under mains pressure whether the machine is running or not, which is why the valve is shut before anything else.
When to call a technician
Call when the water is coming from the tub, from a seam, or from a component behind the panel, because those are strip-downs. Call immediately, having shut the supply valve first, if the leak is at the fill connection — that water arrives under pressure and does not stop when the cycle does.
Nearest pages of this class
What this page does not cover
This page is written for the Moffat dishwasher as a class, not for one family or one model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and the one to read first. Deliberately not here: part numbers, wiring colours and disassembly order, which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
