The E18 error on a Bosch washer means the machine failed to drain water within the expected time window. In most cases, a clogged coin trap filter or a kinked drain hose is the culprit. Clean the filter behind the small access panel on the front lower left of the machine before anything else.
Bosch's E18 fault code signals a drainage failure, meaning water didn't exit the drum fast enough during the drain phase. The most frequent offenders are a packed pump filter full of lint, coins, or debris, and a drain hose that's either kinked or pushed too far into the standpipe. A seized drain pump motor or a failed pressure switch that falsely reports a full drum can also trigger this code without any visible water remaining.
BoschWasherSeverity: moderate87% DIY Success
Time to Fix
10–75 min
Difficulty
beginner
Parts Cost
$8 – $65
Tools Needed
Digital multimeter, Needle-nose pliers
What Does the undefined Code Mean?
When your Bosch washer throws an E18, the control board has detected that the water level sensor didn't confirm an empty drum within the programmed drain window. The machine halts to prevent flooding or motor damage. Nine times out of ten this is a maintenance issue, not a component failure. The drain pump filter, which Bosch recommends cleaning every three months, is the first thing any technician checks on a service call.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Clogged drain pump filter45%
Kinked or blocked drain hose20%
Failed or seized drain pump motor18%
Foreign object jamming pump impeller10%
Defective pressure switch or hose7%
Symptoms You May Notice
Washer stops mid-cycle with standing water visible in the drum
E18 displayed on the control panel, often accompanied by a flashing drum or drain indicator
Loud humming or grinding noise during the drain phase immediately before the error appears
Clothes come out soaking wet even when the spin cycle appears to complete normally
Cycle duration becomes noticeably longer than usual before the machine halts and displays the code
Can you reset a Bosch washer to clear the undefined code?
Unplug the washer from the wall outlet and wait a full 60 seconds. Plug it back in, then hold the Start button for 3 to 5 seconds to clear the fault memory. Alternatively, rotate the program dial to the Off position, wait 30 seconds, then select a new wash program. The reset clears the error display but won't fix the underlying drainage problem if it hasn't been addressed.
Tools Required for Diagnosis
Digital multimeterNeedle-nose pliersPhillips head screwdriverFlat-head screwdriverShallow drain pan (minimum 1 inch depth)Flashlight or headlampOld towelsWire brush for filter cleaning
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range5–30 ohms
ConditionIf Open (OL) or infinite, replace component.
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
Part Name
OEM Number
Estimated Price
Drain Pump Motor Assembly00144978 · $42–$65
00144978
$42 – $65
Drain Pump Filter Cap00421244 · $8–$15
00421244
$8 – $15
Water Level Pressure Switch00499070 · $22–$38
00499070
$22 – $38
Drain Hose Assembly00667851 · $18–$32
00667851
$18 – $32
Frequently Asked Questions
Can I reset the E18 error without fixing the underlying problem?
You can clear the E18 code by unplugging the washer for 60 seconds and plugging it back in. The error will disappear temporarily, but it will return the moment you run another cycle if the drainage problem hasn't been resolved. Don't treat resets as a fix. The machine stops draining for a real reason, and repeatedly ignoring it will eventually burn out the drain pump motor from overheating, turning a free filter cleaning into a sixty-dollar pump replacement. Fix the cause first, then reset.
How often should I clean the Bosch washer drain filter to prevent E18?
Bosch recommends cleaning the pump filter every three months under normal household use. If you're regularly washing towels, pet bedding, or heavily soiled work clothes, monthly cleaning is smarter. You'll know you're overdue when the machine starts taking noticeably longer to drain, or when you hear the pump straining with a low hum near the end of cycles. Filter cleaning takes about five minutes and prevents the vast majority of E18 calls I see in the field. It's the single best preventive maintenance you can do.
My Bosch washer shows E18 but the drum is already empty. What does that mean?
If the drum is empty and E18 still appears, the pressure switch is almost certainly misfiring. The pressure switch monitors water level through a small air-filled hose connected to the tub. If that hose is cracked, clogged with soap residue, or has come loose, the switch can incorrectly report that water is still present even after a successful drain. In this case, the drainage system is working fine but the sensor is giving false readings. Inspect, disconnect, and blow through the pressure hose as your first step in this scenario.
What does replacing the Bosch drain pump cost and is it worth doing?
The OEM Bosch drain pump assembly, part number 00144978, typically runs between forty-two and sixty-five dollars for the part alone. If you're comfortable removing a service panel and disconnecting wire harnesses, it's a manageable DIY repair that takes about forty-five minutes. Professional installation adds sixty to one hundred twenty dollars in labor on top of the part cost. On a washer that's less than eight years old and otherwise in good condition, replacing the pump is worth it. On a machine over ten years old with multiple issues, weigh the total repair cost against replacement first.
Does E18 always mean the drain pump itself needs to be replaced?
Definitely not. In my experience, roughly forty-five percent of E18 calls are resolved by cleaning the clogged filter, which costs nothing. Another twenty percent are fixed by correcting a kinked drain hose. Only about eighteen percent of cases actually require a pump replacement. Start with the free fixes first: clean the filter, check the hose, and look for anything jamming the impeller. You'll solve the problem without spending money more than half the time. Pump replacement should be your last diagnosis after ruling everything else out, not your first instinct.
Models Known to Experience Errors
This repair applies to most Bosch washers with this error code. Common model numbers include: