The short answer
Water left in a Costway countertop or portable dishwasher is almost always the drain hose position or a blocked filter rather than a failed pump. These machines drain by pushing water up a hose into the sink, so where that hose sits decides everything. Check the hose and the filter and you have covered most of these.
What you are actually seeing
- Water stands in the machine at the end of every cycle — Means: on-page
- The machine drains and then water returns — Means: on-page
- Water drains into the sink and then back into the machine — Means: on-page
- A gurgling from the hose during the drain — Means: on-page
- The machine has never drained fully since it was set up — Means: on-page
- Water on the worktop rather than inside the machine — Means: different-fault — Go to: costway-dishwasher-water-leak
- The cycle stops early with a full tub — Means: different-fault — Go to: costway-dishwasher-cycle-fault
- Body: Match what you see before you take anything apart. Water stands in the machine at the end of every cycle. The machine drains and then water returns. Water drains into the sink and then back into the machine. A gurgling from the hose during the drain. The machine has never drained fully since it was set up. Some near-miss symptoms belong on a different page: Water on the worktop rather than inside the machine points at a leak, covered on costway-dishwasher-water-leak; The cycle stops early with a full tub points at a cycle fault, covered on costway-dishwasher-cycle-fault.
Causes, ranked for this machine
- The drain hose is lying in the sink, dropped to the floor, or hooked at the wrong height — Why this rank: First because on this class of machine the hose position is the drain design, and it is disturbed every time the machine is moved
- A blocked filter in the base of the tub — Why this rank: A compact machine has a small filter with no disposer of its own, so it fills quickly
- A kinked drain hose behind or under the machine — Why this rank: Countertop machines are pushed back against a wall, which is exactly where the hose kinks
- The sink itself draining slowly, backing water into the hose — Why this rank: Easy to overlook and it produces a machine that appears to fail intermittently
- A blocked or failed drain pump — Why this rank: Last because everything above it is free and because a genuinely failed pump is rarer than a hose problem
- Body: Ranked for a countertop or portable dishwasher that connects to the kitchen tap with a quick-connect adapter or fills from an internal tank, and drains through a hose into the sink. Most likely: The drain hose is lying in the sink, dropped to the floor, or hooked at the wrong height. First because on this class of machine the hose position is the drain design, and it is disturbed every time the machine is moved. Next most likely: A blocked filter in the base of the tub. A compact machine has a small filter with no disposer of its own, so it fills quickly. Third: A kinked drain hose behind or under the machine. Countertop machines are pushed back against a wall, which is exactly where the hose kinks. Fourth: The sink itself draining slowly, backing water into the hose. Easy to overlook and it produces a machine that appears to fail intermittently. Fifth: A blocked or failed drain pump. Last because everything above it is free and because a genuinely failed pump is rarer than a hose problem.
What to check, in order
- Reposition the drain hose hooked over the sink edge at the correct height
- Remove and clean the filter and look at what comes out
- Trace the hose for a kink where the machine sits against the wall
- Run the sink tap and confirm the sink itself drains freely
- Body: Each check rules out the causes above it. First, reposition the drain hose hooked over the sink edge at the correct height. Second, remove and clean the filter and look at what comes out. Third, trace the hose for a kink where the machine sits against the wall. Fourth, run the sink tap and confirm the sink itself drains freely.
Checks you can safely make yourself
- Hook the drain hose over the sink edge so its outlet is above the water level in the machine but below the worktop, and secure it — Tools: none — Time estimate: a few minutes
- Unplug the machine, bail out the standing water, lift out the filter and rinse it under a hot tap with a brush — Tools: cup, sponge, brush — Time estimate: half an hour
- Pull the machine forward and follow the drain hose along its whole length looking for a kink or a crush point — Tools: torch — Time estimate: a quarter of an hour
- Run the sink tap for a while and confirm the sink drains freely rather than filling — Tools: none — Time estimate: a few minutes
- Run a short cycle with the hose correctly positioned and watch the drain step from start to finish — Tools: none — Time estimate: one short cycle
- Body: Checks an owner can make with the machine unplugged or by watching a short cycle. Step one: Hook the drain hose over the sink edge so its outlet is above the water level in the machine but below the worktop, and secure it. Tools: none. Time: a few minutes. Step two: Unplug the machine, bail out the standing water, lift out the filter and rinse it under a hot tap with a brush. Tools: cup, sponge, brush. Time: half an hour. Step three: Pull the machine forward and follow the drain hose along its whole length looking for a kink or a crush point. Tools: torch. Time: a quarter of an hour. Step four: Run the sink tap for a while and confirm the sink drains freely rather than filling. Tools: none. Time: a few minutes. Step five: Run a short cycle with the hose correctly positioned and watch the drain step from start to finish. Tools: none. Time: one short cycle.
Safety first
Safety
Unplug the machine before bailing the tub or reaching into the base, and wear gloves against broken glass in the sump. Dry the worktop before restoring power. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. unplug-before-service
Where the owner fix ends
Call a technician, or claim under warranty, when the hose is correctly hooked and unkinked, the filter and sump are clean and the sink drains freely, and the machine still holds water. That leaves the drain pump, which is inside the machine.
Nearest pages of the same kind
Generalized information
This page is generalized across the Costway dishwasher line. Countertop machines with an internal tank, countertop machines on a tap adapter and rolling portable machines share the ranking above but not every part, and this page does not cover a specific model or control revision. Family- and model-specific pages, where they exist, are linked below.
Links: - [Common COSTWAY Dishwasher Problems](/blog/costway-dishwasher-problems) - [COSTWAY Dishwasher: Abnormal Noise or Vibration](/blog/costway-dishwasher-abnormal-noise) - [COSTWAY Dishwasher: Does Not Clean or Dry](/blog/costway-dishwasher-cleaning-performance) - [COSTWAY Dishwasher: Controls, Display or Error Code](/blog/costway-dishwasher-control-fault)
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
