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Error code reference

AEG Washer Error Code C1

Water tap closed, valve does not open/interrupted, valve flow too low, or air trap system leaking.

AEG codesAEG washer codes

Water tap closed, valve does not open/interrupted, valve flow too low, or air trap system leaking.

First step from the service manual

Open water tap; replace valve; clean filter; replace air trap.

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

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What C1 means on a AEG washer

The C1 error code on an AEG washer indicates a water inlet problem. The machine's control system has detected that insufficient water is entering the drum within the expected timeframe. This code covers several related failure points: the household water supply tap being closed or restricted, a faulty inlet valve that fails to open or opens only partially, a clogged inlet filter screen, or a leak in the air trap (pressure sensor) system that prevents the machine from accurately detecting water fill levels.

The inlet valve is an electrically operated solenoid component. When energized by the control board, it should open fully to allow water flow. If the valve coil is damaged, if the valve body is clogged with mineral deposits, or if the electrical connection to it is interrupted, flow will be inadequate or absent entirely. The machine monitors fill progress through an air trap system, which uses a sealed air chamber and pressure hose connected to a pressure switch. If this hose is cracked, disconnected, or the air trap chamber itself is leaking, the pressure switch receives inaccurate readings and may report a no-fill condition even when water is actually entering.

Diagnosis should begin with the simplest causes first. Confirm the water supply tap behind the machine is fully open and that household water pressure is adequate. Next, remove and inspect the inlet hose filter screens for sediment or debris blockage. If supply and filters are clear, test the inlet valve for continuity and proper operation. Finally, inspect the air trap chamber and its connecting hose for cracks, loose fittings, or blockages that could cause a pressure sensing fault.

Source: manufacturer service documentation.

Common causes of C1

  1. 01

    Water supply tap closed or restricted

    Wiring / connection

    The tap connected to the inlet hose at the wall may be fully or partially closed. Check that it is turned completely open and that household water pressure is normal.

  2. 02

    Clogged inlet filter screen

    Wiring / connection

    Small mesh filter screens sit inside the inlet hose connection at the back of the machine and can become blocked with sediment over time. Remove the hose, inspect the screens, and clean or replace them as needed.

  3. 03

    Faulty or stuck inlet valve

    Part replacement

    The solenoid inlet valve may fail to open due to a burned coil, internal mineral buildup, or an interrupted electrical connection. A valve that does not open fully will restrict flow below the level the machine requires to proceed.

  4. 04

    Air trap system leak or blockage

    Part replacement

    The air trap chamber and its pressure hose relay water level information to the pressure switch. A cracked hose, loose connection, or blocked chamber can cause the machine to incorrectly report a fill failure even if water is flowing in.

  5. 05

    Interrupted wiring to the inlet valve

    Wiring / connection

    A broken wire or corroded connector between the control board and the inlet valve can prevent the valve from receiving the signal to open. Inspect the harness and connectors at the valve for visible damage or corrosion.

See the test procedure for each cause

Frequently asked questions about C1

What does C1 mean on a AEG washer?
C1 on an AEG washer signals a water inlet fault. The machine has detected that water is not entering the drum correctly, which can be caused by a closed water tap, a blocked inlet filter screen, a faulty inlet valve, or a leak in the air trap pressure sensing system. The washer will not proceed with a cycle until the fault is resolved.
How do I fix the C1 error on my AEG washer?
Start by making sure the water supply tap behind the machine is fully open. Then disconnect the inlet hose and clean the mesh filter screens at the connection point. If the error persists, the inlet valve may need to be tested and replaced. Also inspect the air trap hose for cracks or loose connections, as a faulty pressure sensing system can produce this code.
Will resetting my AEG washer clear the C1 error?
A reset may temporarily clear the C1 code, but it will return at the start of the next cycle if the underlying cause has not been corrected. The machine needs to detect proper water flow before it will run normally. Fix the supply, filter, valve, or air trap issue first, then restart the machine.
Is it safe to use my AEG washer when it shows a C1 error?
The washer will typically stop the cycle and not operate normally when C1 is active, so there is no immediate safety hazard from attempting to run it. However, you should not force repeated cycle attempts without addressing the fault, as running without proper water flow could stress components. Resolve the water supply or valve issue before regular use.
How much does it cost to repair a C1 error on an AEG washer?
If the fix is simply opening the tap or cleaning the filter screens, there is no parts cost involved. Replacing an inlet valve typically runs in the range of $25 to $80 for the part, depending on the model. If the air trap or pressure hose needs replacement, parts costs are generally in the $10 to $40 range. Professional labor charges will add to these figures if a technician is hired.

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