E12
Bosch Dryer
Severity: ModerateWhat Does This Error Mean?
Error E12 means the drain pump on a condenser dryer has faulted or is blocked. Condenser dryers collect moisture from clothes into a water tank — some models have a drain pump to empty this automatically. Cleaning the pump filter and checking for blockages usually resolves E12.
Affected Models
- Bosch WTW87565GB
- Bosch WTH84000GB
- Bosch WQB145B0GB
- Bosch WTW876H0GB
- Bosch Serie 8 Heat Pump Dryer
Common Causes
- Drain pump filter is blocked with lint or debris
- Drain pump has failed electrically or mechanically
- Drain hose is kinked, blocked, or too high causing back-pressure
- Water container is full and the dryer cannot drain the condensed water
- Foreign object has lodged in the pump impeller and stopped it rotating
How to Fix It
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Check the water container — if it is full, empty it and restart the dryer.
Some models display E12 rather than E13 when the water container is full.
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Locate the drain pump filter (usually behind a small access panel at the bottom front of the dryer) and remove it.
Place a towel under the access panel before opening — residual water will drain out.
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Rinse the pump filter under warm running water to remove lint, debris, and any small foreign objects.
A toothbrush helps clear stubborn lint from the filter mesh.
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Check inside the pump housing for foreign objects — a coin or hair clip can jam the pump impeller.
Shine a torch inside the pump recess and use pliers or tweezers to remove any objects found.
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Check the drain hose (if connected to a drain outlet) for kinks, blockages, or excessive height.
The drain hose should not rise above 1 metre — excessive height creates back-pressure the pump cannot overcome.
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Reinstall the filter, close the access panel, and run a test cycle.
If E12 returns after a clean filter and unobstructed hose, the pump itself needs replacement.
When to Call a Professional
Contact a technician if E12 persists after cleaning the pump filter and checking the drain hose. A failed drain pump needs replacement — costs $80–$200 in parts and labor. If your model uses a removable water tank (not a drain pump), check E13 instead.
Frequently Asked Questions
Does every Bosch condenser dryer have a drain pump?
No — many Bosch condenser dryers collect water in a removable tank that you empty manually. Only models plumbed into a drain outlet have a drain pump that can trigger E12. If your dryer has a pull-out water drawer, see E13 (water container full) instead of E12.
How often should I clean the Bosch dryer pump filter?
Bosch recommends cleaning the pump filter every few months under normal use. If you notice dryer cycles taking longer or the dryer is not extracting moisture well, clean the filter sooner. Regular filter cleaning prevents E12 and extends the life of the pump motor.
Can I replace the Bosch dryer drain pump myself?
It is possible for an experienced DIY person, but it involves opening the dryer cabinet and disconnecting electrical connectors. Always unplug the dryer before starting any repair. If you are not confident with appliance repairs, a technician visit is safer and typically costs $80–$200 all-in.