--- title: "Dishwasher not draining" description: "Bosch dishwasher not draining — water standing in the bottom of the tub after a cycle." url: "https://boschmiami.support/symptoms/dishwasher-not-draining/" date_modified: "2026-08-18" Appliance type: "Dishwashers" --- # Bosch dishwasher not draining ### The fastest diagnosis is the code This condition is published under three different labels depending on how old the machine is — a two-digit code, a four-digit code, or a pattern of flashing lights on a model with no display. All three mean the same thing, and all three have the same list of causes. ### What it usually turns out to be - **The filter.** Unscrews by hand, and the most common single answer on this page - **The drain pump cover,** blocked or simply not clicked back after somebody cleaned it - **The hose or the air gap,** kinked or packed with debris - **A disposal knockout plug** never punched out — an installation problem rather than a repair - **The pump,** jammed or failed, which is the only one on this list that needs us ### The three names for one condition The manufacturer has labelled this differently across three generations of machine, and all three are in South Florida kitchens: a two-digit code in the twenties on older units, a four-digit code on newer ones, and on a machine with no digital display, a pattern of flashing lights above the door. They are the same condition with the same causes, and the flashing lights are not a lesser signal — they are how that machine was designed to say it. The filter in the floor of the tub It unscrews by hand. Food, seeds and grease build a mat across it and the machine cannot pull water through. The single most common answer on this page. The drain pump cover, loose or blocked Beside the filter, lifts straight out. A cover not clicked fully back after a previous clean produces exactly the same symptom as a blocked one. The hose, the high loop or the air gap Kinked behind the machine, or an air gap on the counter packed with debris. Common after a machine has been pulled out and pushed back. A new disposal with the plug still in it If the dishwasher has never drained since a disposal was fitted, this is almost certainly it. The knockout plug has to be punched out and frequently is not. The drain pump itself Jammed or failed. A pump that hums without moving water is usually jammed, which is a clean rather than a part. Bail out the standing water A cup and a towel. You cannot see anything under three inches of water and you cannot open the pump cover without emptying it first. Twist out the filter It comes out by hand. Rinse it under a tap with a soft brush. Look at what came off it — that is your answer as often as not. Lift the drain pump cover Beside the filter. Clear anything in there and click the cover firmly back until it seats. A cover left proud stops the machine draining. Then run a cycle and watch If it drains, you are finished. If it does not, photograph the code and book — you have already ruled out the two cheapest causes. The most common call What it usually means Standing water after every cycle A code in the twenties, or four flashing lights Dishes clean on top, wet and gritty below The fastest diagnosis is the code This condition is published under three different labels depending on how old the machine is — a two-digit code, a four-digit code, or a pattern of flashing lights on a model with no display. All three mean the same thing, and all three have the same list of causes. What it usually turns out to be The filter. Unscrews by hand, and the most common single answer on this page The drain pump cover, blocked or simply not clicked back after somebody cleaned it The hose or the air gap, kinked or packed with debris A disposal knockout plug never punched out — an installation problem rather than a repair The pump, jammed or failed, which is the only one on this list that needs us The three names for one condition The manufacturer has labelled this differently across three generations of machine, and all three are in South Florida kitchens: a two-digit code in the twenties on older units, a four-digit code on newer ones, and on a machine with no digital display, a pattern of flashing lights above the door. They are the same condition with the same causes, and the flashing lights are not a lesser signal — they are how that machine was designed to say it. --- **[Read full article: Dishwasher not draining](https://boschmiami.support/symptoms/dishwasher-not-draining/)**