Dishwasher not draining - any ideas?

Why Is My Dishwasher Full of Water After a Cycle?

If your dishwasher isn’t draining and you’re left with standing water at the bottom, the most common causes are a blocked filter, clogged drain hose, or a blockage in the sink waste pipe. Cleaning the filter and checking the hose will often solve the problem. If the issue persists, you may need to look into dishwasher repair to repair the drain pump or another internal component.

If your dishwasher has just gone out of warranty and suddenly isn’t draining, of course the worry is that it needs replacing. However, in many cases, the problem is simply a blockage in the drainage system, which can often be resolved with a few quick checks.

Check the Filter and Sump

A blocked dishwasher filter is one of the most common reasons a dishwasher stops draining properly.

To unblock your dishwasher filter, start by switching off the appliance and unplugging it. Remove the lower basket so you can access the bottom of the dishwasher, where the filter is located.

Twist and lift the filter out, then rinse it under hot running water. Food debris, grease and detergent residue can easily collect here and restrict the flow of water.

While the filter is removed, check the sump, which is the small well beneath the filter where water collects before being pumped out. Carefully wipe away any visible debris so water can drain freely.

Inspect and Clean the Drain Hose

The next step is to remove and clean your dishwasher's drain hose, which carries wastewater from the dishwasher to the sink waste pipe.

Pull the dishwasher forward slightly and make sure the hose isn’t kinked, bent or crushed behind the appliance. Even a small kink can stop water draining properly.

T, disconnect the hose from the sink waste and flush it through with water. Grease or food particles can sometimes build up inside the hose and cause a blockage.

It’s also important that the hose loops upwards before connecting to the waste pipe, as this prevents dirty water from flowing back into the dishwasher.

Check the Sink Waste or Trap

If your dishwasher drains into the same pipe as your kitchen sink, the blockage may actually be in the sink waste or U-bend rather than the appliance itself.

Cleaning the trap under the sink can often resolve drainage problems if grease or food debris has built up in the pipework.

If the dishwasher connects to a waste disposal unit, make sure the unit is clear and working correctly.

When to Call a Professional

If you’ve cleaned the filter, checked the hose and inspected the sink waste but the dishwasher still isn’t draining, the problem may be caused by a faulty drain pump, sensor or another internal component.

At that point it’s best to contact a qualified appliance engineer who can diagnose the issue and replace any faulty parts.

If you need help, you can find trusted local domestic appliance repair specialists by using the search bar at the top of this page.