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Bosch Washer Not Draining: E18 Error Code and Pump Filter Fix

Quick Answer

Bosch E18 is the drain error and the most common Bosch washer complaint. The filter is behind the small door on the lower-right front panel - Bosch designed a quarter-turn cap with a built-in drain flap so you can drain slowly without a bucket flood. Turn slowly, let it drain, then unscrew and clean. This fixes E18 in about 70% of cases in under 5 minutes.

Bosch washer E18 is THE drain error code and the most common Bosch washer complaint. The pump filter on Bosch front-load washers is behind a small door on the lower right front panel. Bosch's filter design is particularly easy to access - a quarter-turn cap with a built-in drain flap. Turn the cap slowly and water drains through the flap into a pan below. Once drained, unscrew completely and remove debris. Bosch uses a uniquely shaped pump impeller that is less prone to sock jams than other brands, but coins and small items still clog it. If E18 persists after cleaning the filter, the drain hose may have a restriction. Bosch drain hoses use a specific internal diameter that is narrower than some competitors - lint and debris can accumulate at the wall connection.

BoschWasherSeverity: mediumDifficulty: intermediate75% DIY Success
Time to Fix
15–90 min
Difficulty
intermediate
Parts Cost
$40 – $80
Tools Needed
Multimeter, Screwdriver

What Does the NOT-DRAINING Code Mean?

Bosch not draining: E18 error.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Pump filter clogged (coins, debris)40%
Drain hose lint buildup at wall connection24%
Pump motor failed14%
House drain clogged12%
Drain hose kinked10%

Symptoms You May Notice

  • Appliance not draining
  • Performance issue
  • May show error code

Can you reset a Bosch washer to clear the NOT-DRAINING code?

Unplug 60 seconds. Plug in and test.

Tools Required for Diagnosis

MultimeterScrewdriverFlashlight

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

1

Check the most common cause described in the guide above.

Check the most common cause described in the guide above.

2

Check secondary causes and error codes if displayed.

3

If basic checks fail, consult a professional or run manufacturer

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
Bosch Drain PumpModel-specific · $40–$80

Repair vs. Replace Calculator

Appliance Age (Years)7 Yrs
Labor Approach
Our Verdict
REPAIR
Estimated Cost: $60 (Parts) vs $1400 (New Machine)

Frequently Asked Questions

How much does Bosch washer not draining repair cost?
Most repairs cost $100-400 depending on the component. Simple fixes like cleaning or resetting are free.
Is my Bosch washer worth repairing?
If under 10 years old and repair is under 50% of replacement cost, repair is worthwhile.
Can I fix this myself?
Many fixes are DIY with basic tools. Gas and sealed-system repairs need a professional.

Same Fix Works on These Brands

Bosch shares the same hardware platform with these brands. The diagnosis and repair steps are identical.

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Models Known to Experience NOT-DRAINING Errors

This repair applies to most Bosch washers with this error code. Common model numbers include:

WAW285H2UC, WAT28402UC, WGA12400UC

Last verified for technical accuracy on March 15, 2026