Why Won’t My Dishwasher Drain?

Why Won't Your Dishwasher DrainWithin the first two of our “customer questions” posts, we’ve looked at “How to Change a Vacuum Drive Belt” and “How to Change a Cooker Hinge”. Now, in the final part we look at why your dishwasher won’t drain.

If your dishwasher won’t drain water during the cycle it doesn’t mean your appliance is destined for the scrap heap. Instead, there are a few quick and easy checks you can make to repair your appliance and bring it back to its former glory.

These checks include:


The filters within your dishwasher may only be a small component, but they play a big part in helping to prevent debris from being washed into the pipes, causing blockages. Unfortunately, failure to regularly clean the filters in your dishwasher can cause them to become blocked, which in turn can prevent water from draining away.

If your dishwasher has stopped draining, we would recommend removing the dishwasher filters from the appliance and giving them a thorough clean. This should hopefully result in the dishwasher once again being able to freely drain water.

Water Hose:

If the filters are clean and free from debris, then we would recommend checking the water hose, at the back of the machine.

When checking the hose you should first check there are no kinks within it, and that there is enough room behind the dishwasher for the hose, without it being squashed.

If after checking the hose there are no obvious signs of kinks or it being squashed, then we would recommend disconnecting it from the appliance and the sink drain, enabling you to check for any blockages. Whilst the hose is disconnected, it’s also a good idea to run water through it, if the water can flow easily through the hose then it is highly unlikely that this is the cause for your dishwasher not being able to drain water.

Check Valve:

The check valve is what stops the water from coming back into the dishwasher during its cycle; but if it’s stuck in position then it can also prevent water from being drained from the appliance. The check valve can normally be found in the outlet to the pump which is attached to the drain hose. And it is important, if your dishwasher isn’t draining, to check that the valve is not stuck in the closed position.

Along with the check valve, it’s also important to make sure the check ball is not stuck. The check ball is a small plastic ball, within the check valve. If the check ball gets stuck, water will not be able drain away from the appliance.

If after checking these three components of your dishwasher it is still failing to drain, then the fault may lie with the drain pump. The pump is made up of several other parts, making the detection of a defective element difficult and often involving the disassembling of the entire pump or replacing the whole unit, which is a difficult repair and should really only be carried out by an experienced DIY-er.

For more tips and advice on how to keep your dishwasher running, visit our blog and advice centre.

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