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Error code reference

Ariston Dishwasher Error Code AL 03

Timeout draining

Ariston codesAriston dishwasher codes

Timeout draining - machine does not detect open pressure switch contacts within 4 minutes of starting the drain cycle.

First step from the service manual

Check drain pump connection, drain pump for clogs (toothpicks, bones), drain pipe position and height (0.4m to 1m from floor), and TRIAC timer.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What AL 03 means on a Ariston dishwasher

AL 03 is a drain timeout fault that triggers when the pressure switch contacts fail to open within 4 minutes of the drain cycle starting. In a properly functioning system, the drain pump removes water from the tub, causing the water level to drop. As the level drops, the pressure switch detects the change and opens its contacts, signaling the control board that the tub is empty. When this signal does not arrive within the 4-minute window, the machine logs AL 03 and halts operation.

The most frequent cause of this fault is a restriction somewhere in the drain path. The drain pump impeller can become jammed by small debris such as toothpicks, bone fragments, or broken glass, preventing the pump from moving water effectively. The drain hose position is also critical: the hose must rise to a height between 0.4 meters and 1 meter from the floor. If the hose is too low, water can siphon back into the tub, keeping the pressure switch closed and preventing the fault from clearing.

Electrical and control-side failures can also produce AL 03. A faulty TRIAC on the control timer board can prevent the drain pump from receiving the correct activation signal, meaning the pump never runs at full capacity or does not run at all. The drain pump's electrical connection should also be inspected for loose terminals or corrosion. If the pump and drain path are both clear and correctly installed, the TRIAC or control board is the next component to evaluate.

Source: manufacturer service documentation.

Common causes of AL 03

  1. 01

    Clogged drain pump impeller

    Wiring / connection

    Small objects such as toothpicks, bone fragments, or broken glass can jam the pump impeller, severely reducing or completely stopping water flow. Remove the pump cover and inspect the impeller for debris.

  2. 02

    Incorrect drain hose height

    Wiring / connection

    If the drain hose is routed below 0.4 meters or above 1 meter from the floor, water may siphon back or fail to discharge properly, keeping the tub water level elevated. Verify the hose rises to a point within the specified 0.4 to 1 meter range.

  3. 03

    Loose or corroded drain pump connection

    Wiring / connection

    A poor electrical connection at the drain pump can cause intermittent or total pump failure without any visible mechanical blockage. Inspect the pump connector and terminals for looseness, corrosion, or burnt contacts.

  4. 04

    Faulty TRIAC on the timer control board

    Part replacement

    The TRIAC is the switching component that sends power to the drain pump during the drain cycle. A failed TRIAC can prevent the pump from activating at all, even when the pump itself is mechanically sound.

  5. 05

    Failed drain pump motor

    Part replacement

    If the pump impeller is clear and electrical connections are solid but the pump still does not run, the pump motor itself may have failed. This requires replacing the drain pump assembly.

See the test procedure for each cause

Frequently asked questions about AL 03

What does AL 03 mean on a Ariston dishwasher?
AL 03 is a drain timeout error. It means the dishwasher started the drain cycle but the pressure switch did not detect an empty tub within 4 minutes. The machine stops to prevent potential issues and waits for the fault to be addressed. The cause is typically a blocked drain pump, an incorrectly routed drain hose, or a faulty TRIAC on the control board.
How do I fix AL 03 on my Ariston dishwasher?
Start by checking the drain pump for debris such as toothpicks or bone fragments that may be jamming the impeller. Next, confirm the drain hose is positioned between 0.4 and 1 meter above the floor. Inspect the pump's electrical connector for loose or corroded terminals. If those checks pass, the TRIAC on the timer board should be tested or replaced.
Will resetting the dishwasher clear the AL 03 error?
A reset may temporarily clear the fault code, but the error will return as soon as the machine attempts another drain cycle if the underlying cause has not been corrected. You need to resolve the drain restriction or electrical fault first. Once the repair is made, the code should not reappear.
Is it safe to use my dishwasher when AL 03 is showing?
It is not recommended to continue running the dishwasher while AL 03 is active. The machine has stopped because it could not drain properly, and forcing more cycles could leave standing water in the tub or stress other components. Address the drain fault before running additional wash cycles.
How much will it cost to repair an AL 03 error on an Ariston dishwasher?
If the fix is simply clearing a clog from the drain pump, the repair can cost very little beyond your time. Replacing the drain pump motor typically runs in the range of $50 to $150 for the part, plus labor if a technician is involved. A TRIAC or control board repair or replacement can range from $80 to $250 or more depending on parts availability and whether a full board replacement is needed.

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