Why is My Dishwasher Not Draining?

No-one wants to open their machine and discover it hasn’t drained fully but, don’t lose it just yet. You might manage solve the fault before you have to call a plumber or purchase a new machine.

Standing water in your dishwasher may be caused by any number of components a few of which can be straightforward to fix. Therefore, before you call a dishwasher repair service here is a lineup of probable things you can identify on your own. A few of which are not even caused by the dishwasher itself.

Check the dishwasher wasn’t stopped mid-cycle

It is probable that there is nothing preventing your dishwasher from emptying. Instead, the cycle might have been stopped mid-way.

The program might have been interrupted for a number of of reasons. Little fingers pressing buttons, accidentally pushing against the controls, a power cut or opening the dishwasher mid-program may all stop the cycle from completing and mean your machine doesn’t drain.

If you think this might be the case, or you think it could be a good idea to check start your machine again on a short program.

A proportion machines may have a drain cycle meaning it’s well worth consulting your owners manual or doing a quick internet search to check.

Check the garbage disposal

If your dishwasher is attached to the disposal inspect this first as an obstructed disposal will block your dishwasher from emptying. Turn on the waste disposal with plenty of water to make sure there are no blockages.

If you do uncover an issue drain un-blocker or a natural alternative may be used to remove the obstruction and this may deal with the fault.

Inspect the sink waste for issues

If you sink is draining inefficiently this might signify an issue with the drains rather than a problem with your dishwasher.

In the case that the kitchen sink is emptying slowly you can try putting some bicarb and vinegar down the plughole, leaving it for a few minutes and then flushing it away with hot water.

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

This might be all you need to do to allow the appliance to drain so start a quick rinse and empty cycle to check. If not you can remove the dirty water by hand using a jug and a towel and troubleshoot the next few possible issues.

At this point make sure you disconnect the machine to avoid electrocution.

If in the process of any one of these checks you believe you have found and fixed the fault there is no need to continue to the next issue. Just start an empty cycle to check your machine is repaired.

Inspect and wash the filters

Any number of things could block the filters including popcorn, paper from containers, plastic film covers and smashed glass. Clear plastic lids may also be difficult to spot if you aren’t looking for it.

Take out the filter and scrub it thoroughly before replacing it. Not all dishwashers have their filter in the same place so you might need to refer to the instructions for this.

Is the drain pipe obstructed?

The next area to examine is the waste water pipe. Stuck food, a kink in the hose or a crushed hose could all impede your machine from emptying.

Subject to the location of the waste pipe (generally the corrugated one) you may manage inspect it simply by lifting away the base alternatively you may be required to move the machine out from the wall.

Have a look at the pipe first to discover if there are any kinks or it’s been squashed. You might be able to fix these issues by hand which should deal with the issue, but it’s worth noting that once this has happened it is significantly more likely to happen again so you may wish to purchase a new hose.

If you are unable to find any obvious kinks or obstructions you could take off the waste pipe from the dishwasher and blow through it to discover any blockages. Make sure you line the floor with newspaper or towels before you remove the hose as even if you have emptied the machine there might still be water in the hose.

If you can’t blow air through the hose this may be the reason your machine isn’t emptying.

Take off the other end of the hose and give it a good clean to clear the blockage. If you can’t shift the obstruction or the waste pipe is slit or degraded purchase a brand-new one. If you may remove the blockage then re-attach the hose and start a quick cycle to check that you have solved the issue.

You may also inspect where the pipe attaches to the sink. This is a common point for debris to build up so if you do remove the waste pipe give this point a good scrub as well.

Check the drain valve

You could manually check the drain valve to check it hasn’t seized. The drain valve will most often be located at the base of the dishwasher on the valve bracket. Examine your instructions if you can’t see it.

Pushing down on the valve or giving it a jiggle should be sufficient to tell you if it’s stuck. If you can see anything stopping it from moving carefully extract this. If you can’t, this could be when you should ring a repair person unless you are confident in ordering and swapping out the valve yourself.

Examine your pump is not blocked

Your dishwasher pump uses impellers that could get obstructed by pieces of glass or other debris. Check your impellers aren’t obstructed by taking off the safety cover and ensuring that the impellers can rotate freely.

Listen to your dishwasher while it’s running

If the dishwasher is making funny noises your pump or motor might be faulty and need to be repaired.

Call a plumber

If you have been through the above list and the fault remains, or you suspect the pump, pump valve or motor are broken, it may be a good time to call in the professionals.

This way though you will at least have the means to give them more information and have prevented needing to pay a big call-out fee for a blocked drain.