What are the symptoms of error code E18?

Dryer stops mid‑cycle with E18 displayed, Water collects in the base of the dryer, Dryer runs but clothes remain damp, Audible humming from the condensate pump, Dryer shuts off shortly after starting

What causes error code E18?

Blocked condensate pump filter, Clogged drain channel or internal hose, Failed condensate pump motor, Float switch stuck due to debris or water overflow, Kinked or obstructed external drain hose (if equipped)

How do I fix error code E18?

Restart the dryer to clear temporary pump faults., Empty the water tank (if using tank mode)., Clean the condensate pump filter and drain channel., Inspect internal hoses for blockages or kinks., If the pump does not activate, it may require replacement.

Bosch Dryer - E18 Error Code

Condensate pump or drain system malfunction.

Meaning

Condensate pump or drain system malfunction.

The E18 error indicates that the dryer is unable to pump out collected condensation water. Bosch explains that this code appears when the condensate pump is blocked, the drain path is restricted, or the pump motor fails to move water to the reservoir or drain hose. The dryer stops operation to prevent internal water buildup, overheating, or moisture damage.

Symptoms

Dryer stops mid‑cycle with E18 displayed
Water collects in the base of the dryer
Dryer runs but clothes remain damp
Audible humming from the condensate pump
Dryer shuts off shortly after starting

Causes

Blocked condensate pump filter
Clogged drain channel or internal hose
Failed condensate pump motor
Float switch stuck due to debris or water overflow
Kinked or obstructed external drain hose (if equipped)

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Step-by-Step Fixes

Restart the dryer to clear temporary pump faults.
Empty the water tank (if using tank mode).
Clean the condensate pump filter and drain channel.
Inspect internal hoses for blockages or kinks.
If the pump does not activate, it may require replacement.

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Safety Notes

Unplug the dryer before accessing internal components.
Expect water to spill when opening the pump area; keep towels ready.
Do not operate the dryer if water is pooling inside the unit.

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Applicable Models

Show Models

Serie 4 Condenser Dryers: WTN85201GB, WTN85202GB, WTN85280GB, WTN85290GB
Serie 6 Condenser Dryers: WTG86402GB, WTG86403GB, WTG86409GB, WTG86411GB, WTG86490GB
Serie 8 Heat Pump Dryers: WTW87560GB, WTW87561GB, WTW87564GB, WTW87568GB, WTW87660GB, WTW87661GB, WTW87680GB
Heat Pump Self‑Cleaning Condenser Models: WTW855R9SN, WTW855R8SN, WTW87NH1UC, WTW87NH2UC
Compact 24‑Inch Heat Pump Dryers: WTG86400UC, WTG86401UC, WTG86402UC, WTG865H2UC
Older Condenser Models: WTE84106GB, WTE86300GB, WTE86301GB, WTE86304GB

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Other Bosch Dryer Error Codes

Show All Error Codes

Model-Specific Notes

Many Bosch Serie 6 and Serie 8 dryers include an automatic pump‑priming cycle when E18 is detected, during which the controls may not respond until the internal float switch resets.

Disclaimer

The information provided on this page is for educational and informational purposes only. Repairs involve electrical, mechanical, and water-related risks. Always follow manufacturer instructions and consider contacting a qualified technician for diagnosis or repair.