Answer first
On a Wizard dishwasher, not draining usually comes down to a choked filter and sump, with a check valve letting water return next. Establish first whether the machine has ever drained properly, because a machine that never has is an installation fault rather than a failure.
What you actually observe
- Standing water in the bottom of the tub after a cycle — Usually with soil suspended in it.
- A smell when the door is opened — Water that never leaves the sump goes stale.
- NEAR MISS — the sink beside it also drains slowly — Then the house drain is the fault and the machine is doing nothing wrong.
Causes, most likely first on this platform
- A choked filter and sump — Standing water with food in it is the sump telling you it is full before it is telling you anything else. First on an older machine, where the screen and sump take years of soil and no one has ever taken them out. Standing water is the first and often the only symptom.
- A check valve letting water return — The tub empties and then refills itself from the hose while the machine sits idle. Second: a check valve of this age sticks, so the tub empties and then quietly refills itself from the hose.
- A kinked or crushed drain hose — Third. A hose that has been behind the same cabinet for decades has a permanent kink in it whether or not anyone put one there.
- A failed drain pump — Fourth, and the one that decides whether the machine is worth keeping: on a machine of this vintage a pump is both the likeliest wear item and the hardest part to source.
Check in this order, and why that order
- Lift the filter out and look into the sump — Standing water with soil in it is the sump telling you it is full before it tells you anything else. It goes first: top-ranked above, and free to rule out.
- Watch whether the tub refills itself while the machine sits idle — Water that comes back after a good drain is a check valve, not a pump. Second: the next cause in the ranking, and this check separates it from the first.
- Pull the machine forward and look at the drain hose — A hose crushed against the cabinet back has usually been that way since installation. Third, once both checks above come back clean.
What an owner can safely check
- Bail the standing water out, then remove and rinse the filter and screen — A jug and a sponge get the tub dry enough to see what is underneath.
Tools: jug, sponge, soft brushAbout 20 min
- Watch whether the tub refills itself while the machine sits idle — Water that comes back after a good drain is a check valve, not a pump. Note what you find.
About 5 min
- Ease the machine out and straighten the drain hose — Keep the door shut while you move it, and watch the supply line so it does not snag.
About 20 min
- STOP HERE if the next step needs the machine unplugged and a panel removed — Anything behind the outer panel of a machine holding water and mains wiring is a service call.
Before you take anything off
Safety
Unplug the machine or switch off its breaker before removing any panel; a capacitor can hold a charge after the power is off, and this machine holds water and mains wiring in one cabinet. Never defeat the door latch switch, and never reach into a sump or a drain pump that is still plugged in: broken glass goes through a rubber glove.
Where an owner check ends
Call once the filter, the hose and the air gap are clear and water still sits in the tub, because the pump is the next item and it is behind the panel. Call sooner if water is reaching the floor as well, because a machine that cannot drain will eventually overflow. On a machine of this age, ask what the repair costs against what the machine is worth before agreeing to it, and ask whether the part can still be sourced.
Where to go next in this class
What this page does not cover
This page is written for the Wizard dishwasher as a class, not for one family or model line. Where a family- or model-specific page exists for your unit it is linked here, and it is the more specific answer. Not here: part numbers, wiring colours, torque figures, panel sequences and component ratings, which differ by family.
Links: - [Wizard dishwasher leaking onto the floor: where it starts](/blog/wizard-dishwasher-water-leak) - [Wizard dishwasher leaving dishes dirty: what to check first](/blog/wizard-dishwasher-cleaning-performance) - [Willz dishwasher not draining: water left in the bottom](/blog/willz-dishwasher-drainage-failure)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
