Why is My Dishwasher Not Draining?

No-one wishes to open their machine and discover it hasn’t drained properly but, don’t panic just yet. You may have the means to fix the error by yourself, without having to call a plumber or invest in a new machine.

Standing water in your machine may be caused by a number of things some of which can be simple to figure out. Therefore, in advance of calling a dishwasher repair service here is a selection of possible things you can troubleshoot on your own. A proportion of which are not even a fault of the dishwasher itself.

Ensure the cycle wasn’t interrupted

It is possible that there is nothing preventing your machine from emptying. Instead, the cycle could have been cut short.

The program could have been interrupted for multiple of reasons. Kids pushing buttons, accidentally leaning against the control panel, a power outage or opening the machine mid-cycle might all prevent the cycle from completing and mean your machine doesn’t drain.

If you suspect this could be the circumstance, or you feel it could be a good idea to check run your machine again on a short cycle.

Some dishwashers might have a drain capacity meaning it’s worth checking your instructions or checking online to make sure.

Check the garbage disposal

If your dishwasher is plumbed into the disposal examine this before you do anything else as a blocked garbage disposal will prevent your machine from emptying. Turn on the garbage disposal using fast running water to make sure there are no blockages.

If you do find an obstruction drain un-blocker or a natural alternative could be used to clear the obstruction and this might solve the problem.

Check the sink for blockages

If you sink is draining reluctantly this might suggest a plumbing issue rather than a problem with your dishwasher.

If the sink is emptying slowly you may try putting some bicarbonate of soda and white vinegar down the drain, letting it sit for a while and then flushing it through with boiling water.

A plunger could also be employed to try and remove the obstruction.

This could be all you need to do to permit your machine to drain so start a quick rinse and drain cycle to check. If this hasn’t sorted the issue you can remove the water by hand using a cup and a sponge and have a look at the next few possible issues.

At this point make certain to unplug the machine to stay safe.

If during one of these investigations you think you may have discovered and solved the fault you don’t need to go through the remaining steps. Just run an empty cycle to check your dishwasher is now draining as it used to.

Check and scrub the filters

Popcorn, paper from tupperware, plastic film lids and broken glass, plus food debris, can all block the dishwasher filter. Clear plastic lids may also be difficult to spot if you aren’t looking for it.

Take out the filter then give it a thorough clean before replacing it. Not all machines have their filter in the same location so you could need to look at the owners manual for this.

Is the waste hose obstructed?

The next place to inspect is the drain pipe. Stuck food, a kink in the hose or a crushed hose could all impede your machine from draining.

Depending on the position of the waste hose (normally the ribbed one) you might be able to look at it simply by taking off the base or you may be required to move the dishwasher out from the wall.

Have a look at the hose in the first instance to discover if it has been crushed or kinked. You might manage manually remove any kinks which will most likely deal with the issue, but it’s worth noting that once this has occurred it is significantly more inclined to happen again so you may wish to buy a new hose.

If you are unable to find any obvious kinks or obstructions you can disconnect the waste hose from the pump and blow through it to discover any blockages. Be sure to line the floor with newspaper or towels before you remove the hose as even if you have emptied the machine there may still be waste water in the pipe.

If you can’t blow through the waste hose this could be the issue.

Take off the hose at the sink end and give it a good flush through to clear the obstruction. If you are unable to dislodge the obstruction or the pipe is cracked or worn purchase a new one. If you may remove the obstruction then put the hose back and run a short program to find out if you have solved the fault.

You may also inspect the point where the pipe attaches under your sink as well. This is a likely point for blockages to occur so if you do remove the pipe give this area a thorough scrub as well.

Check the drain valve

You can check the drain valve by hand to make sure it hasn’t seized. The drain valve will usually be located at the base of the machine on the valve bracket. Check your owners manual if you can’t see it.

Depressing the valve or wiggling it a bit will likely be adequate to tell you if it’s seized. If you can see anything blocking it remove this. If you are unable to, this might be when you should ring a repair person unless you are happy in ordering and replacing the component yourself.

Inspect your pump is not broken

Your appliance pump uses impellers that could be blocked by broken glass or other debris. Check your pump isn’t broken by removing the safety cover and making sure the impellers can be easily rotated.

Listen to your dishwasher while it’s running

If it doesn’t sound normal your pump or motor could be broken and need to be repaired.

Call a plumber

If none of the above examinations has repaired the problem, or you suspect the pump, pump valve or motor are not working, it might be the moment you need to get the professionals.

At least having done your best to fix the problem yourself you have managed to avoid needing to pay a hefty call-out charge for a blocked hose.

More Dishwasher Problems:

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