Why is my Dishwasher not Draining

Just when you thought you would not have to read anything else about a dishwasher, you get this. See: How does a dishwasher work? and the ever popular cleaning strategies to improve the cleaning power of a dishwasher at: How to clean and maintain a Dishwasher?

Click Here to Be sure to follow safety precautions when working on appliances.

There are several possible casuses for water left in the dishwasher. Some simple, some not so simple.

• Full Garbage Disposal
  
• Clogged Drain
• Plugged Air Gap (this device prevents siphoning of sewer or drain water into the dishwasher)
  
• Plugged Anti-Siphon Device
• Bad Pump
• Bad Timer
  

The first order of business is to determine how much water is left in the dishwasher. It should be filled just below the door seal when it is full. That is about 3 inches of water. If part of the water is gone but not all of it at the end of a cycle, the problem most likely is a problem in the drain.

The waste water enters the pump through a screen and possibly though a soft food disposal. Then is pumped into a drain hose. The drain hose is most likely connected to a Air Break device located on the outside of the wall, just outside the kitchen, or under a slotted metal looking cup on the sink beside the faucet. There will be a drain hose going from the air gap to the drain, most likely a garbage disposal. If you do not have a garbage disposal, the it will be connected to the sink drain. Although I have seen a lot of goofy installations, these two scenarios would be the most likely.

If you run the dishwasher and water comes out of the air gap and pours into the sink or pour on the ground outside the kitchen, then the drain is plugged on the air gap or in the hose that goes to the drain or garbage disposal.

Start by checking the garbage disposal, is it filled with food? It might be blocking the dishwasher drain. Run the disposal and check to to see if the dishwasher is draining properly.

Remove the hose, it will be held on place by hose clamps from the drain or garbage disposal on one end and the air gap on the other end. Check the drain hose for a blockage, clean it thoroughly with a brush or rag n a coat hanger wire and wash it off with the hose. Check inside of the air gap outlet to see if something is stuck in there, I have found the most interesting things in the air gap. I am still scratching my head regarding a ring, a plastic bag, a hair scrunchie, and what looked like a part of a snake. EWWWWWWWWWWWW!

Make sure it is clear of debris. Replace the hose, Next remove the hose from the air gap that comes from the dishwasher. Place the end of the hose in a bucket. Turn the dishwasher on and let it drain into the bucket. The force of water coming out will be like a garden hose is all is working right. Let it drain into the bucket for a few seconds giving every opportunity for it to flush anything in the hose into the bucket. If the force of the water is good, then it is draining from the dishwasher correctly. Check the inlet side of the air gap and make sure that it is free of debris and other blockages.

If you found a clogged hose or air gap, it is now fixed. Run a cycle in the dishwasher to check to see if the water drains properly. If it does, then the problem is fixed.

If after cleaning the drain hoses, and the screens, a possible problem could be with an anti siphon device. Only some dishwashers are equipped with these, but they are a nuisance to get to. The anti siphon device is located where the drain hose connects to the pump. It normally looks like a small ball in a cage located in the end of the drain hose. How this works is that the ball is forced toward the drain hose when the pump is pumping water, this opens the drain and water flows freely. When the pump stops pumping water, the ball floats back to the pump drain an blocks it so that no water in the drain hose or from the drain can enter the dishwasher. If food or other debris gets lodged into this contraption, then the drain may be blocked. It has to come off and cleaned up.

If the anti siphon device is clear, then the problem at this point is solved.

If the problem persists, then the problem could be with the pump or the timer. If it is a poorly performing pump, only a small amount of water will pump out. If it is the timer it may not pump long enough. Does the pump make unusual noises or loud noises? If the pump is not working efficiently and making noises or not pumping at all, then it is probably a bad pump.

Does the timer stop before the end of the cycle or get stuck sometimes in the cycle? If the timer does not complete the cycle then it is probably a bad timer. Does the timer knob turn hard or skip? Time to replace the timer.

The pump is an easy job on some dishwashers and on others it is very difficult. You will need to use the model number to find the pump. Once you have located the pump, then based on that, you can determine the difficulty of the job. GE dishwashers are one of the easiest. At any rate, the dishwasher will have to come out.

To take the dishwasher out, turn off the power and water. Disconnect the water supply, electrical (quite often this is just a plug). and the drain. The dishwasher is normally held in place with a couple of screws driven into the bottom of the counter through brackets on the top of the dishwasher, remove those. The dishwasher should now slide out and you can gain access to it. I would use this strategy, take the dishwasher out and see if you can manage to get the pump out. If it seems easy enough and a job that you can do, then order the new pump. If you cannot figure it out and complete the job it may be time to get a new dishwasher. A pump assembly can be kind of expensive and with a service call and repair it is probably going to top $200. Maybe time to move on.

If you decided it is the timer, then you are in for a thrill.   Just kidding.  Changing the timer out can be daunting.     It is located in the door panel and is sometimes difficult to access.   You will have to open the door.   If it is held in place with a spring and pulley system where you have access to the springs in the front, it might help to unhook the spring so that the door does not keep closing.   If the spring is difficult to work with, then it would be a good idea to leave it alone.

Start by removing the hold down screws in the inside liner.   Removing the liner will give you access to most dishwasher timers.  Some dishwashers have conveniently located the timer in a separate enclosure.   With the liner removed, you will be able to see the timer.  It is fairly easy to remove the timer and replace it.   If you are confused at all along the way, take the time to sketch the assembly out.   BE cautious, some dishwasher have some of the mechanisms attached or held in by the front liner.