Bosch Washer Error Code E18 (Step-By-Step Guide to Fix It)

The Bosch washing machine error code E18 indicates a water blockage or water drainage issue with your appliance. 

There are several causes for the error to display on your washing machine. I looked into the issue when I had the same problem. Here is what I found about the error code E18.

Bosch Washing Machine Error Code E18

The Bosch washing machine error code E18 revolves around water blockage or drainage issues. When the tank does not have enough water to perform its regular functions, that’s when the code pops up on the display. 

It’s usually one of several pieces of equipment that cause the water issue. A temporary blockage is the likely reason. However, a part failure is possible, too. 

Here is a list of the 4 potential causes of the E18 error code: 

  1. Drain hose blockage.
  2. The drain pump is blocked up.
  3. The drain hose is kinked or broken.
  4. Sump hose pipe obstruction.

Drain Hose Blockage

A blocked drain hose occurs due to blocked filters in the hose. Various debris gets inside hoses and blocks up the siphon. The number of buttons, coins, and other debris trapped inside is amazing!

Fortunately, Bosch makes it easy to access and clean them out. 

How to fix – Disassemble the Drain Hose to Unclog it

Follow these 8 steps to clear a blocked drain hose:

  1. Put on a pair of rubber gloves for heat protection. 
  2. Turn off the appliance and unplug it.
  3. Slide an empty tray or food container below the hose as a water collector. 
  4. Loosen the siphon spigot’s hose clip.
  5. Slide the drain hose off it and let it drain into the container. Be careful, because the water is likely hotter than expected. 
  6. Check both the drain hose and siphon connection for blockages. Remove any found using a flathead screwdriver. 
  7. Reattach the siphon to the hose and reinstall the drain hose.
  8. Select the “Drain” test program to verify if the hose and assembly are watertight.

Blocked Drain Pump

A blocked appliance pump happens in life. It is accessible enough to clean it and it’s housing too. 

How to fix – Drain the Hose and Clear the Drain Pump Interior

There is no other way but to fix the clogged drain pump by hand.

Resolving a drain pump blockage is a two-part process.

First, handle the drain hose:

  1. Power off the appliance and unplug it.
  2. Open the service flap. It’s found at the front of the Bosch washing machine in the bottom-right corner. Then remove it.
  3. Slide a container or tray in front of the service flap area to capture any water release.
  4. Put on rubber gloves to protect from the hot water. 
  5. Gently pull out the drainage hose.
  6. Remove its cap and let the water drain from it. Beware, it’s sometimes hot!
  7. Replace the cap at the end of the hose.
  8. Refit the hose back into position, secured by two fixed-position clips. 

Second, remove the drain pump cover:

  1. Place a microfiber cloth beneath the area to capture water release.
  2. Grip the gray-colored pump cover. Rotate it approximately 2 cm counterclockwise. 
  3. Pull the cover apparatus outward and lay it to one side.
  4. Let the water drain out fully.
  5. Clean the remaining residue found. 
  6. Clean the housing interior and thread (be careful not to lose them).
  7. Rotate the impeller inside the revealed internal apparatus to confirm it is functional and not impinged.
  8. Replace the components and fit the pump cover back into position.
  9. Check for leaks: Fill a water jug with 1 liter of H2O. Now pour it through the detergent drawer. Monitor for leaks. 
  10. Once the seals look watertight, run a pumping program cycle (or another one) to check it fully.

Drain Hose Kinked or Broken

A drainage hose splits or has a kink. These cause blockages, resulting in the error code E18 displaying until resolved. 

Replacing a broken hose is important, instead of attempting to reseal it. Water leaks risk damaging important electrical connections. Drain hose kinks typically aren’t hard to resolve. 

How to fix – Straighten Out the Hose and Check for Hose Damage

Resolving a drainage hose kink, or twist is easy enough. Untwist the hose so it lays flat. 

If the kink was present too long, a hose crack is possible. If so, tape or superglue may work temporarily. However, it’s best to replace the hose with a new or moderately used one from an identical Bosch washing machine model ASAP. 

If the blockage was simply a kink in the hose, unkinking the hose to fix that and running a new wash cycle is sufficient. The washing machine display should return to normal and the E:18 error code vanishes. 

Sump Hose Pipe Obstruction

You can find the sump hose pipe inside the washing machine. The manufacturer fits filter balls to the end of sump pipes to stop larger debris from entering. It’s a larger diameter than most pipes inside washing machines, so this does a good job. 

It’s possible for minor items – from a small washcloth to drier sheets – to find their way inside the pipe. A blockage triggers the same E18 error code and regularly trips people up who don’t know about it. 

How to Fix – Tilt the Washing Machine Back and Carefully Clear Obstructions

The sump hose pipe is located inside the machine, between the drain pump housing and the drum itself. 

Here are the steps to follow:

  1. Lift and angle the washing machine backward.
  2. Prop it up at the front to maintain the angle.
  3. A metal band holds the sump pipe in position. Use a crosshead screwdriver to unscrew the metal band to release the sump pipe. 
  4. Look for tiny pieces of tissue paper, cleaning cloths, and other items that have found their way inside. Remove them. 
  5. Double-check that the hose is now all clear. 
  6. Rescrew the metal band back in place to secure the sump hose pipe back into position. 

Wrapping Up

The Bosch washing machine error code E18 has 4 likely causes. Sometimes, it’s necessary to run through more than one to be sure. Re-test after each applied solution to see if that fixed the error code. 

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