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Error code reference

Bosch Washer Error Code Er:12

Water supply time exceeded

Bosch codesBosch washer codes

Water supply time exceeded — faulty inlet valve, wire harness, or hose.

First step from the service manual

Run tests P8/P9/P13; check water inlet valve, wire harness, and hoses.

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

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What Er:12 means on a Bosch washer

Er:12 on a Bosch washer indicates that the machine was unable to fill with water within the expected time window. The control board monitors how long the inlet valve has been open versus how much water has actually entered the drum. When fill time exceeds the programmed threshold, the board logs Er:12 and halts the cycle to prevent the pump and motor from operating without adequate water present. This is fundamentally a water supply fault, but the root cause can originate from several different points in the fill circuit.

The fill circuit includes the household water supply, the inlet hoses, the inlet valve assembly, and the wiring harness connecting the valve to the control board. If the inlet valve solenoid coil is open or has drifted out of specification, it may not open fully or at all, restricting flow. A kinked, clogged, or improperly connected supply hose can produce the same symptom. The wire harness between the control board and the valve is also a known failure point, as corrosion or a broken conductor will prevent the solenoid from receiving its activation signal.

Diagnosis begins with running tests P8, P9, and P13 in the machine's service test mode, which exercise the inlet valve directly and allow a technician to observe valve response independent of the main wash program. Visually inspect both supply hoses for kinks and verify that the household shutoff valves are fully open. Check the inlet valve solenoid coils for continuity and confirm the harness connectors are fully seated and free of corrosion before condemning any component.

Source: manufacturer service documentation.

Common causes of Er:12

  1. 01

    Faulty water inlet valve

    Part replacement

    The inlet valve solenoid coil can fail open-circuit or become mechanically stuck, preventing water from entering the drum. Running service test P8 or P9 will activate the valve directly so you can verify whether it opens and allows flow.

  2. 02

    Kinked or blocked supply hose

    Wiring / connection

    A kinked inlet hose or a clogged inlet screen at the back of the machine can severely restrict flow without triggering a complete no-fill condition. Straighten hoses, remove them, and inspect the mesh screens at both the hose fitting and the valve inlet for debris.

  3. 03

    Household water supply issue

    Wiring / connection

    If the shutoff valves behind the washer are partially closed or water pressure is unusually low, fill time will exceed the allowable limit. Confirm both hot and cold shutoff valves are fully open and that other fixtures in the home have normal pressure.

  4. 04

    Damaged or corroded wire harness

    Part replacement

    The harness connecting the control board to the inlet valve solenoid can develop broken conductors or corroded terminals, preventing the solenoid from receiving its activation signal. Inspect the harness connectors at both ends and test for continuity through each wire.

  5. 05

    Control board not signaling the valve

    Part replacement

    If the inlet valve and harness both test good during P8, P9, and P13 service tests but the error persists, the control board may not be outputting the correct signal to open the valve. This is the least common cause and should be ruled out only after all other components have been confirmed functional.

See the test procedure for each cause

Frequently asked questions about Er:12

What does Er:12 mean on a Bosch washer?
Er:12 means the washer was unable to fill with water within the time limit set by the control board. The machine stopped the cycle automatically to protect internal components from running dry. The fault points to the water inlet valve, the supply hoses, or the wiring harness connected to the valve. Service tests P8, P9, and P13 are used to isolate the specific cause.
Can I fix Er:12 on my Bosch washer myself?
Some causes of Er:12 are straightforward to address without professional help. Check that the water supply shutoff valves behind the washer are fully open, and inspect the inlet hoses for kinks or a clogged filter screen at the valve connection. If these checks do not resolve the error, testing the inlet valve solenoid and wiring harness requires a multimeter and some comfort with appliance diagnostics, so a technician may be appropriate at that point.
Is it safe to continue using my washer when Er:12 is displayed?
You should not attempt to run wash cycles while Er:12 is active. The washer has halted the cycle because it detected insufficient water, and forcing operation without adequate water in the drum can damage the pump, motor bearings, and other components. Resolve the fill issue before resuming normal use.
How much does it cost to repair a Bosch washer showing Er:12?
Repair cost depends on the failed component. If only the supply hose needs replacement or a clogged screen needs cleaning, costs are minimal, typically under $30 for parts. A replacement water inlet valve usually runs between $40 and $120 for the part alone, plus labor if a technician performs the work. Control board replacement, if required, is the most expensive outcome and can range from $150 to $350 or more for parts.
Will resetting my Bosch washer clear the Er:12 error code?
Resetting the washer may temporarily clear the error code from the display, but the code will return as soon as the machine attempts to fill again if the underlying problem has not been corrected. A reset is useful for confirming a repair was successful, but it is not a fix on its own. Address the root cause in the fill circuit before relying on a reset to resume normal operation.

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