Avanti Dishwasher: Will Not Drain
A dishwasher that will not drain has an obstruction far more often than a failed pump, and on a machine installed under a sink the obstruction is as likely to be in the household plumbing as in the appliance. This page takes the same fault from a different starting point: not which subsystem is likeliest on an Avanti dishwasher, but when the trouble started. This is a compact cabinet with very little air around its condenser, so clearance and ventilation outrank component failure. What ranks first here is something you can correct yourself in under an hour, which is the reason to work down the list in order rather than book a visit straight away.
What you are actually seeing
- Check your symptom against this list first.
- Dirty water sitting in the filter well.
- Water backing up into the sink when the dishwasher pumps.
- The machine drains slowly and leaves a film on everything.
- Not this fault: If dishes are dirty but the machine drains, the cleaning-performance page is the right one.
Causes, grouped by when it started
- One entry per onset pattern first — the strongest candidate for each way this fault can begin on an Avanti dishwasher — and the remainder after them. Read the label, find the pattern that matches yours, and start there rather than at the top.
- Air gap or high loop missing or blocked — Why: The drain hose must rise above the flood level of the sink, either through an air gap on the worktop or a high loop under it. Without it the machine siphons; with a blocked air gap it cannot drain at all. — Onset: Has been like this since the unit was installed or moved
- Blocked filter and sump — Why: The filter assembly in the base of the tub catches everything that comes off the dishes, and on many machines it is a manual-clean part that owners never learn about. — Onset: Got worse gradually over weeks or months
- Glass, label or bone fragment in the pump — Why: Small hard debris that gets past the filter jams the impeller. The pump then buzzes without moving water, which sounds different from a pump that is not running. — Onset: Started suddenly, between one use and the next
- Waste disposal not cleared, or the knockout plug never removed — Why: Where the drain hose connects to a disposal, the disposal has to be run and clear. On a new installation the disposal’s knockout plug is often left in, which blocks the drain completely from day one. — Onset: Got worse gradually over weeks or months
What to check, and in what order
- This order follows the onset groups above, so it is deliberately different from the companion page. Neither is wrong; they are two routes through one fault.
- Pin down when it started and whether it happens every time. — Why: A fault that appeared between one use and the next has a different cause set from one that crept up over months, and this answer alone removes most of the list.
- Lift out the filter assembly and look at what is under it. — Why: It is the most common cause, it is designed to be owner-serviceable, and it takes five minutes.
- Run the waste disposal, then start a drain cycle. — Why: It clears the most common shared-plumbing cause without touching the appliance.
Checks you can safely do yourself
- Stop at the first step that would put a meter on live terminals.
- Switch the machine off at the breaker and scoop the standing water out of the tub with a cup and a sponge. — Tools: Cup, sponge, towels
About 15 min
- Twist out the filter assembly, wash it under a running tap with a soft brush, and clear the sump beneath it. — Tools: Soft brush, gloves
About 20 min
- Run the waste disposal for thirty seconds with cold water, then run a rinse cycle on the dishwasher. — Tools: None
About 20 min
- Lift the cap off the air gap on the worktop and clear any debris inside it. — Tools: Torch, cloth
About 15 min
Before you touch anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. — Id: unplug-before-service
Switch off the dishwasher at its breaker before reaching into the sump or removing any panel; many machines are hard-wired with no plug to pull. The water in the tub can be hot after a cycle and can contain glass fragments — wear gloves and use a sponge rather than your fingers.
Where the owner checks end
Call a technician when one of these is true, and not before.
When the filter, air gap, disposal and hose are all clear and the pump is silent at the drain phase. When the impeller is damaged or jammed with glass. When water backs up into the sink, which is a plumbing job rather than an appliance one.
Sources
General guidance- 29 CFR 1910.147 — The Control of Hazardous Energy — US Occupational Safety and Health Administration, fetched 2026-09-06
Nearest pages of the same kind
What this page does not cover
Links down: - [Common Avanti Dishwasher Problems](/blog/avanti-dishwasher-problems-2)
This page is generalized: it covers the Avanti dishwasher line as a whole and does not narrow to a family, a model number or a serial range. The overview at avanti-dishwasher-problems-2 routes down to every problem class on this machine, including any family- or model-specific page beneath this one.
Other faults on this machine
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
