What this error means
The E18 error code on your Bosch washing machine means the machine cannot drain the water away — usually because the pump filter or drain hose is blocked.
When your Bosch washing machine displays the E18 error code, it has detected that water is not draining within the expected time. The machine monitors how long it takes to empty after a wash or rinse cycle — if it takes too long, it stops and shows E18 to protect itself and your home from a potential flood. In the vast majority of cases this is caused by a blocked pump filter (the small round access panel at the bottom front of the machine), a kinked or blocked drain hose, or a blockage further along the waste pipe under your sink. This is one of the most common Bosch washing machine faults and, reassuringly, it is also one of the easiest to fix yourself without any tools or specialist knowledge.
Also known as: E:18, e:18, e18, F18, f18, F:18, f:18
What you'll need first
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Step-by-step
Symptoms to look for
- Water sitting in the drum at the end of a cycle
- Machine stops mid-cycle and will not continue
- E18 displayed on the control panel
- Gurgling sounds from the pump area
- Machine door will not open (child lock triggered by standing water)
How to fix it
Before you do anything else, switch the washing machine off at the wall socket and unplug it. Pull the machine forward slightly so you can reach the back. Lay old towels on the floor around the front and back of the machine — you will be dealing with water and things can get messy.
On most Bosch washing machines the pump filter is behind a small flap at the bottom front of the machine, usually on the right-hand side. You can open it with your fingernails or a flat-head screwdriver. Inside you will see a round plastic cap and sometimes a small emergency drain hose with a plug on the end.
Place a shallow baking tray or lipped container directly under the filter cap. If there is an emergency drain hose, pull out the plug and let the water flow into the tray — empty and repeat until nothing more comes out. If there is no separate drain hose, slowly unscrew the filter cap anticlockwise by a quarter turn at a time to release the water gradually.
Once the water has drained, unscrew the filter cap fully and pull it out. Rinse it thoroughly under a running tap, removing all fluff, fibres, coins, hair clips, or any other debris. Also shine a torch into the filter housing and use your fingers or a cloth to remove any blockage sitting in the cavity itself.
Go to the back of the machine and follow the corrugated drain hose. Check the entire length for kinks, sharp bends, or crush damage. If it is connected to the standpipe under your sink, make sure the end of the hose is not pushed in more than 15 cm — pushing it in too far creates a siphoning effect that can cause drain faults.
If the drain hose feeds into the same waste pipe as your sink, run the sink tap and check that water flows away freely. A blocked sink trap can cause the machine to drain slowly and trigger E18. Remove and clean the sink trap if needed.
Screw the filter cap back in clockwise until it is snug. Do not overtighten — hand-tight is enough. Close the access panel. Plug the machine back in and select a short spin-only or rinse-and-spin programme. Watch the machine during the drain phase to confirm the water clears fully and the E18 error does not return.
When to call an engineer
- E18 returns within a few cycles of cleaning the filter
- Drain pump making a loud grinding or humming noise but water is not moving
- No blockage found in filter or hose but machine still will not drain
- Burning smell coming from the pump area
- Error persists after checking filter, hose, and waste pipe
Frequently asked questions
What does the E18 error code mean on a Bosch washing machine?
Is E18 on a Bosch washing machine serious?
Can I still use my washing machine if it shows E18?
How do I find the pump filter on my Bosch washing machine?
How often should I clean my Bosch washing machine filter?
Why does my Bosch washing machine keep showing E18 after I have cleaned the filter?
This video shows you how to resolve the Bosch E18 Error Code
- Possible Causes
- How to Clean the drain pump
- How to clean the drain hose
🎯 What is most likely causing your Bosch E18 error?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Drain pump | £20 - £25 | 🛒 Amazon UK → |
| Drain pump filter cap | £10 - £15 | 🛒 Amazon UK → |
| Drain Pump | £15 - £30 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.