Dishwasher says "AL03"

There is an apparently quite large family of dishwashers that signal a problem with the water outlet with the code "AL03". My Ariston LD87 is one of them, and one fine day, it said "AL03", and refused to work.

After I started to run out of kitchen space for dirty dishes, I began to investigate the problem. Fortunately, a search quickly turned up plenty of evidence that I wasn't the first to experience that problem, and that this usually didn't involve major repair. In particular, this discussion thread was very useful, but there are still several details worth knowing, and a few pictures wouldn't hurt either.

So here we go ...

What does "AL03" mean ?

When the dishwasher begins or ends operation, it pumps out the used (dirty) water. If it detects that, after a few minutes, there is still water left, it shows the dreaded "AL03" and stops. There are many things that can prevent the dishwasher from successfully removing water, from the inside to the outside: There is of course little we can do if some complex component, such as the drain pump, is truly broken. But in all discussions I've found on the topic, the causes of "AL03" were far more benign.

Diagnosis

Conceivably, the sensor that detects the presence of water could be broken as well. This possibility is quickly ruled out by checking the water level in the dishwasher. There should be several liters left. (But it's still safe to open the door.) The next thing to check would be the filters. There's a roughly triangular metal plate with a short plastic tube in the middle, and under that, there is another tube and a filter ring. I'm not quite sure how one would manage to get enough dirt into the dishwasher to block these filters, but it seems to be possible.

Anyway, let's assume the filters have been cleared but we still get "AL03". It's now worth trying to clear the outlet with a plunger. This may or may not remove objects stuck in the pump. Be warned that plunging may just dislocate the offending object without completely removing it, and "AL03" will return once the object has settled in a suitable spot again.

Before plunging, the water level should be lowered. A quick way to accomplish this is to remove the filters and to scoop out the water with a cup or similar. Leave a bit of water in the filter hole for the plunger, or, to make the work more pleasant, remove all the dirty water with a sponge, and add a bit of fresh water. The goal of plunging is to remove the object that is blocking the pump, not to remove some large obstacle clogging a pipe, so successful plunging will not announce itself by the water vanishing with a gargling sound. Instead, one has to check whether things work by starting the dishwasher and letting it go through a short cycle.

If the problem persists, the next step would be to check the outlet hose. Detaching that one from the fixed pipes can sometimes be quite messy, but if this is possible, it's worth the effort to check. Detach the exit hose from the piping and put it into a bucket. (There will be some water spills.) Then start the dishwasher. If the water now rushes into the bucket, the piping is the culprit.

Alas, normally, nothing promising happens at this stage. So the next step is to work on the pump.

Preparations

The drain pump is roughly in the center of the bottom of the dishwasher. To get at it, we have to lay the dishwasher on one of its sides (left or right, not front not rear). Putting it upside down should given even easier access, but will certainly spill even more water, and may cause other problems. (I haven't tried the upside-down approach yet.)

Before doing anything else, disconnect power. The components inside the dishwasher operate at mains voltage, and there's plenty of humidity to make any involuntary electrocution a smashing success.

When tilting the dishwasher, most of the remaining water will run out. If you haven't done so already, you should first pump or scoop out as much water as possible (e.g., with a cup), and take care of the rest with a sponge. Even when the inside appears completely dry, there will still be a liter or so left, so prepare to deal with this.

Going in

Our goal is to remove the bottom plate, extract the pump, and then open it and see if there's anything stuck inside.

Access to the bottom plate

The bottom plate is held by six screws, three at the front and three at the rear. The ones in the front corners are hard to reach, because the decorative plastic "bumper" gets in the way. So we remove this bumper first.

The following pictures show one corner of the "bumper", with the screw already removed, and the screws that hold it in place:

 

There is one screw for each corner. After removing the screws, the bumper can be pulled towards the front. I found it impossible to get it off while the dishwasher was lying on its side, so I put it back in an upright position, cleaned up the spills, pulled the bumper/cover, and turned it over again.

Unscrewing the bottom plate

The bottom plate is held by short Phillips screws:

On the front and rear side, there is one at each corner and one in the middle. The following two pictures show the front and rear:

 

To remove the screws in the front corners, a screwdriver with a long shaft is necessary, as shown here:

Removing the bottom plate

After removing the screws, the bottom plate can be pulled off easily. In fact, it may just fall off. This is a first peek inside:

There is a leak sensor at the bottom that is connected with a cable to the main assembly:

After disconnecting the cable, the bottom plate can be put away. We now have a clear view of the dishwasher's innards:

Getting our bearings

The drain pump is the white thing in the middle of this picture. It's easily identified because that's what the exit hose connects to:

We will now extract the pump. First, disconnect the cable from the motor.

Disconnecting the drain hose

We need to separate the pump from the drain hose not only because it ties the pump to the dishwasher, but also because the pump needs to be rotated in order to detach it from the water outlet of the inner chamber of the dishwasher, and the drain hose prevents this rotation.

The drain hose is held in place by a quite sturdy clamp. Fortunately, not too sturdy to resist the application of pincers:

 

Once the clamp is loose, it can be pulled onto the hose:

The hose can now be pulled away. As usual, water will spill. It may be a good idea to put some receptacle under the inner end of the hose, and raise the outer part of the hose, to drain it completely.

At this moment, it's also easy to verify if the drain hose itself is clogged.

Detaching the pump

We're now close to our goal. The pump must be turned counter-clockwise. Yet another Phillips screw prevents it from doing so:

Now the pump can be turned and then pulled out of the machine:

And here we have the object of our desire:

Opening the pump

The pump is held by three T15 torx screws:

Any reasonably well-equipped hardware store should have a suitable screwdriver. Torx screws can be handled with a regular screwdriver, but it's awkward at best, and will probably damage the screw. Now we can open the pump:

With a little luck, the offending object will now be in plain view. In my case, it was a piece of plastic that's been broken off the bottom of the cutlery basket.

Putting it back together

Before doing a test run, the pump should be installed and the bottom plate attached. Make sure that the leak sensor is properly connected, or the dishwasher will do more complaining. My LD87 has a short 12 minutes program which only rinses the plates. This is perfect for testing.

Werner Almesberger, 16-JUN-2007.