Why is My Dishwasher Not Draining?

No-one wants to open their machine and discover it hasn’t emptied properly but, try not to panic just yet. You might have the means to rectify the issue by yourself, without having to call a plumber or purchase a brand-new machine.

Your machine failing to empty can have multiple of causes a proportion of which are easy to rectify. So, before you call a dishwasher repair service try this list of probable components you may identify yourself. A proportion of which are not even related to the dishwasher itself.

Ensure the dishwasher wasn’t stopped mid-program

It is possible that there is nothing preventing your machine from draining. Rather, the cycle might have been interrupted.

The cycle might have been stopped mid-way for a number of of reasons. Little fingers pressing controls, mistakenly pushing against the controls, a power cut or opening the machine mid-program might all prevent the program from completing and mean your dishwasher doesn’t empty.

If you suspect this might be the situation, or you think it may be worthwhile checking run your dishwasher again on a short program.

A few machines might have a drain capacity so it’s well worth having a look at your instruction manual or consulting google to find out.

Check the waste disposal

If you have a disposal inspect this before you do anything else as an obstructed disposal will stop the machine from draining. Turn on the disposal using fast running water to ensure there are no obstructions.

If you do find a blockage drain unclogger or a natural alternative could be used to unclog the obstruction and so this could resolve the error.

Inspect the plumbing for clogs

If you sink is emptying slowly this might signify a plumbing issue as opposed to a problem with your dishwasher.

If the sink is emptying reluctantly you can attempt putting a little bicarb and vinegar down the plughole, letting it sit for a while, then washing it away with hot water.

A sink plunger might also be employed to try and dislodge the obstruction.

This could be enough to permit the dishwasher to work again so start a short cycle to check. If not you could remove the standing water by hand using a cup and a towel and check a few more possible issues.

Make sure you unplug the dishwasher to stay safe.

If in the process of any one of these investigations you believe you may have discovered and fixed the issue you don’t need to go through the rest of the steps. Just complete an empty cycle to check the dishwasher is now draining as it should.

Check and clean the filters

Popcorn, paper from tupperware, plastic covers and broken glass, plus food debris, may all block the machine filter. Clear film may also be difficult to see if you don’t look closely.

Take out the filter then wash it thoroughly before replacing it. Not all dishwashers have their filter in the same place so you could need to refer to the instruction manual for this.

Is the waste pipe blocked?

The next component to inspect is the waste water pipe. Many things could cause a blockage including a build up of food debris, a kink in the hose, or a crushed hose. All of which could all stop your machine from draining.

Subject to the location of the waste pipe (normally the corrugated one) you may manage inspect it by removing the base or you may need to move the machine away from under the counter.

Have a look at the hose first to see if there are any kinks or it’s been squashed. You may have the means to manually straighten out any kinks which will most likely solve the issue, however, it’s worth noting that once this has occurred it is much more inclined to happen again so you might need to order a new hose.

If you can’t see any obvious kinks or obstructions you can remove the drain hose from the pump and blow through it to check for any blockages. Be sure to line the floor with newspaper or towels first as there might still be dirty water in the hose.

If you can’t blow through the hose this might be the problem.

Take off the other end of the hose and then give it a good flush through to get rid of the obstruction. If you are unable to get rid of the blockage or the waste hose is split or worn invest in a new one. If you can remove the blockage then put the hose back and start a quick program to double check that you have repaired the error.

You may also examine the point where the hose connects to the sink as well. This is a common spot for a build-up of gunk so if you happen to take off the pipe give this area a good scrub as well.

Examine the drain valve

You could examine the drain valve by hand to ensure it hasn’t stopped working. The drain valve will generally be found in the bottom of the dishwasher on the valve bracket. Check your manual if you’re unsure.

Pushing down on the valve or wiggling it a bit should be adequate to let you know if it’s seized. If you are able to see an object blocking it remove this. If you can’t, this might be the right time to ring a plumber unless you are confident in procuring and replacing the part yourself.

Inspect your pump is not blocked

Your water pump uses impellers that can be blocked by pieces of china or other debris. Check your impellers aren’t obstructed by removing the safety cover and ensuring that the impellers can be easily rotated.

Listen to your dishwasher while it’s on

If the dishwasher doesn’t sound right your dishwasher pump or motor might be damaged and need to be repaired.

Call a plumber

If you have been through the above list and the fault persists, or you think the pump, pump valve or motor are not working, it might be a good time to call a plumber.

At least having attempted to troubleshoot you have avoided having to pay a big call-out charge for a blocked drain.

More Dishwasher Problems:

  • Dishwasher Being Loud
  • Dishwasher Not Turning On
  • Dishwasher Leaking
  • Dishwasher Not Drying