Bosch Washer Not Draining: E18 Error & 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.
When your Bosch stops mid-cycle with a full drum, you're almost always looking at the coin trap filter or a drain hose issue. These pumps are quiet and efficient but they don't have the brute force to push through even a modest amount of debris. Ignore that E18 and you'll end up with standing water that turns sour fast, and that smell gets baked into the door gasket. What should cost you nothing turns into a $200 seal replacement.
Bosch Washer Not Draining: E18 Error & Pump Filter Fix
Here's the deal: most Bosch not-draining calls I go out on are a clogged filter. Full stop. Before you panic about a dead pump, spend five minutes at that little access door on the lower right. The other thing most people don't know is that Bosch is picky about drain hose height. The manual actually specs the standpipe insertion depth, and if your plumber put it in too far, you'll get siphoning that mimics a pump failure every single time.
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
Cycle stops mid-wash with a full drum of standing water and the E18 code flashing on the display.
Machine gets all the way through the wash phase and then just sits there humming for a few minutes before giving up with an error code.
You can hear the pump running during the drain phase but the water level never actually drops.
Laundry comes out completely soaking wet, not just damp, because the spin ran but the water never actually left the drum.
Door is locked and absolutely won't open because the control board thinks there's still water present.
Can you reset a Bosch washer to clear the NOT-DRAINING code?
Turn the dial to Off and unplug the machine. Leave it unplugged for a full 60 seconds, not 10 seconds, a full minute. This lets the capacitors drain and the control board fully reset. Plug it back in and dial straight to a Drain or Spin cycle. Don't run a full wash right away. Watch and listen. If you can hear the pump engage and water starts moving, the E18 clears on its own once the pressure sensor reads empty.
Tools Required for Diagnosis
Phillips #2 screwdriverFlathead screwdriverMultimeterFlashlightShallow baking pan or trayOld towels (at least 4)Needle-nose pliersWork gloves
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range5–15 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
Bosch Drain PumpModel-specific · $40–$80
Model-specific
$40 – $80
Frequently Asked Questions
How much does fixing a Bosch washer not draining actually cost?
If it's just the filter, this costs you nothing except 10 minutes and some wet towels. A replacement drain pump runs $60 to $120 for a genuine Bosch part, or $40 to $70 for a quality aftermarket. If you're hiring it out, expect $250 to $400 total depending on your area and what time of day you call. Honestly though, I've driven out to fix Bosch draining issues where the whole job was pulling a bra underwire out of the filter. Check the filter first and save yourself a service call.
Is my Bosch washer worth repairing?
Yeah, almost always if it's under 10 years old. Bosch front-loaders are genuinely built better than most domestic brands. The brushless motors and stainless drums on these things are built to last. A drain pump or a clogged filter is routine maintenance, not a death sentence for the machine. The only times I tell people to consider replacing is if the main control board fries, or if the outer tub bearings start making that jet-engine scream, because a bearing job on a Bosch usually runs $400 or more in labor alone.
Can I fix a Bosch not draining issue myself?
Cleaning the filter? Do it yourself, 100%. It's literally listed as required maintenance in your owner's manual. Replacing the pump is a step up in difficulty but still manageable if you're comfortable pulling a front panel and working around sheet metal edges. Those edges can be sharp, so wear work gloves. The hardest part is usually just getting the machine tilted or moved enough to access everything. Grab a friend for the heavy lifting part.
Why does my Bosch smell terrible after a drain error?
Standing water in the drum and pump housing goes bad fast, especially after a few hours. That water gets into the door gasket folds and the detergent drawer and starts growing mold and mildew. Once you've fixed the drain issue, run a hot maintenance wash with a cup of white vinegar or a washing machine cleaner tablet. Pull the rubber door gasket back and wipe it down with diluted bleach solution. If you still smell it after a couple of cleaning cycles, the gasket itself needs to come off for a deep clean or replacement.
How often should I clean the Bosch pump filter?
Bosch recommends every month or two, but honestly most people never do it until the machine breaks. If you've got kids, pets, or you wash a lot of athletic gear, aim for once a month. It takes 5 minutes and the access door is right there at the bottom front. I pulled a filter out last week that looked like it had never been cleaned in 7 years of use. Don't be that person. Regular filter cleaning is the single best thing you can do to keep these machines running long-term.
What's the part number for the Bosch drain pump?
The most common replacement pump for the 300 and 500 series is Bosch part number 00144978, which fits a wide range of models. But double-check your specific model number before ordering because Bosch has used a few different pump assemblies across their lineup over the years. The model number sticker is on the inside of the door frame. Cross-reference that with the Bosch parts site or a parts supplier before you buy anything.
Same Fix Works on These Brands
Bosch shares the same hardware platform with these brands. The diagnosis and repair steps are identical.