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Error code reference

Ariston Dishwasher Error Code AL 01

Overflow alarm

Ariston codesAriston dishwasher codes

Overflow alarm - water detected in base pan by float switch, signalled 9 seconds after base pan float switches from normally open to closed.

First step from the service manual

Check for leak from water line; inspect all pipes, sleeves, and water line components for leaks.

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

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What AL 01 means on a Ariston dishwasher

AL 01 is the overflow alarm for Ariston dishwashers. It activates when water accumulates in the base pan, the drip tray located at the bottom of the appliance beneath the wash tub. A float switch mounted in this pan monitors water level. Under normal dry conditions, the switch sits in an open state. When enough water collects to lift the float, the switch closes, and the control board registers this change. The alarm triggers 9 seconds after the float switch transitions from normally open to closed, giving the system a brief delay to prevent false trips from minor condensation or vibration.

The most common cause of base pan flooding is a leak somewhere in the water delivery or circulation system. This includes the inlet hose, internal supply lines, hose sleeves, pump housing seals, door gasket, or any threaded fitting that has loosened or degraded over time. The water does not necessarily come from a dramatic failure. Even a slow drip from a cracked hose sleeve or a worn door seal can gradually fill the pan to a level that trips the float switch.

Once AL 01 is active, the dishwasher will typically halt its cycle and may engage the drain pump to remove water from the tub. The base pan itself does not drain automatically in most configurations, so water that has collected there must be removed manually after identifying and correcting the source of the leak. Simply resetting the control board without addressing the root cause will not clear the condition permanently, as the float switch will trip again if water continues to enter the pan.

Source: manufacturer service documentation.

Common causes of AL 01

  1. 01

    Leaking water inlet hose or connections

    Part replacement

    The inlet hose or its fittings can develop cracks, loose connections, or deteriorated seals that allow water to drip into the base pan. Inspect the full length of the supply line and all connection points for moisture or mineral buildup indicating a slow leak.

  2. 02

    Damaged or worn door gasket

    Part replacement

    A torn, compressed, or misaligned door gasket allows water to escape around the door perimeter during the wash cycle and run down into the base pan. Visually inspect the gasket for cracks, gaps, or sections that no longer press firmly against the tub rim.

  3. 03

    Leaking internal hose sleeve or spray arm supply line

    Part replacement

    Internal hoses connecting the pump, spray arms, and sump can develop splits or loose clamps over time. Check all internal sleeves and connections for signs of moisture or water tracks leading toward the base pan.

  4. 04

    Pump housing seal failure

    Part replacement

    The circulation or drain pump seals can wear and allow water to seep out around the pump body, particularly during high-pressure wash phases. Look for water residue or corrosion near the pump assembly.

  5. 05

    Float switch fault or debris obstruction

    Part replacement

    In rare cases, the float switch itself may be stuck in the closed position due to debris accumulation or a failed switch component, triggering AL 01 even when the base pan is dry. Inspect the float for free movement and confirm the pan is actually dry before suspecting switch failure.

See the test procedure for each cause

Frequently asked questions about AL 01

What does AL 01 mean on a Ariston dishwasher?
AL 01 is the overflow alarm, indicating that water has been detected in the base pan, the drip tray located beneath the dishwasher tub. A float switch in the pan transitions from open to closed when water lifts the float, and the alarm is signaled 9 seconds after that transition occurs. This is a safety feature designed to stop the appliance and alert you to a leak before water damage spreads.
How do I fix AL 01 on my Ariston dishwasher?
Start by pulling the dishwasher out enough to inspect the water inlet line, all visible hoses, and their connection points for any signs of leaking. Check the door gasket for tears or compression failure as well. Once you locate and repair the leak, the water in the base pan must be removed manually since the pan does not self-drain. After the pan is dry and the leak is corrected, the float switch will return to its open position and the alarm should clear.
Is it safe to use my Ariston dishwasher when AL 01 is showing?
No, you should not continue running the dishwasher while AL 01 is active. The alarm indicates water is present in the base pan, which means there is an active or recent leak. Running the appliance without addressing the leak risks additional water damage to the floor or cabinetry, and continued operation could stress other components.
Will resetting the dishwasher clear the AL 01 error?
A control board reset will not permanently clear AL 01 if the underlying leak has not been repaired. As soon as the dishwasher runs again, water will continue to enter the base pan, the float switch will close again, and the alarm will return within 9 seconds of that transition. The float switch must physically return to its open position, which requires the pan to be dry and the leak source to be corrected.
How much does it cost to repair an AL 01 error on an Ariston dishwasher?
Repair costs vary depending on the source of the leak. Replacing a door gasket or an inlet hose is generally a lower-cost repair, typically in the range of $20 to $80 for parts, plus labor if a technician is involved. A pump seal or internal component replacement can cost more, potentially ranging from $100 to $300 or higher depending on parts and labor rates in your area.

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