Bosch Dryer E03 — What It Means & How to Fix It
E03 is a drainage warning: condenser water can't get away, usually because the condensate hose is kinked or blocked, or the siphon is clogged.
What this code means
Ventless Bosch dryers condense moisture and pump it down a small water hose, either into a condensate container or a floor drain. E03 means that path is struggling — the classic causes are a kinked or blocked drain hose and a clogged siphon, which the dedicated official guide walks through as the first checks. Clearing the path usually clears the code.
The US support page lists E03 as a blocked or kinked drain hose, while Bosch's dedicated E03 guide adds the siphon check and the European table covers the condensation hose — slightly different details across pages, same family of fixes, which is why the checks below cover both.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Condensate hose kinked or pinched | Very common | Yes — straighten it |
| Drain hose blocked where it exits the dryer | Common | Yes — clear it |
| Clogged siphon or drain connection at the sink or floor trap | Occasional | Partly — visible checks |
| Drain pump fault | Less common | No — technician job |
What you can try yourself
- Unplug the dryer before touching hoses.
- Find the condensate water hose (the manual shows its route) and look for kinks, pinches, or anything crushing it.
- Detach the outlet end into a bucket and check for blockage; flush the hose gently.
- If the dryer drains to a sink or floor trap, check that siphon or connection for lint.
- Refit the hose without kinks, plug back in, and run a short program. E03 returning with a clear path points to the pump — a technician job.
When to call a technician
- Water pooling around the dryer — turn it off and get a towel.
- E03 returns after the whole hose path is verified clear and straight.
- The dryer trips the breaker or hums loudly during the drain phase.
Typical professional repair cost: Clearing a kink or blockage is free. A persistent E03 with a verified-clear hose path usually means the drain pump — a parts-and-labor repair quoted by an authorized Bosch service partner.
Frequently asked questions
Why would a dryer show a drain error when there's no water anywhere?
Condenser dryers collect water internally and pump it out continuously. If the pump can't push water, the machine reports the drainage problem even when the floor around it is dry — the failure is inside the hose run or the pump itself.
Can I pull the condensate container out to clear E03?
On models that use a container, an unseated or full container can contribute. Re-seat it properly as part of the hose check — it's on the same water path.
Sources checked
Error meanings can vary by model. This guide was checked against the documentation above; use the manual for the model number on your own appliance when it differs.
Related Bosch codes
- Bosch Dryer E01 E01 and E02 are your dryer telling you the fluff filter needs attention — almost always lint buildup or the filter not fully seated, occasionally residue left by liquid fabric softener.
- Bosch Dryer E04 E04 is the overloading warning — too much laundry for the drum to process. Split the load into smaller batches and it usually clears.
- Bosch Dryer E12 E12 is the tricky one: official US text links it to heat-pump limescale buildup on condenser models, and to overheating from restricted airflow on others. Start by cleaning the airflow path.
- Bosch Dryer E16 E16 is the door message — the machine believes the door opened mid-cycle. Close it firmly, make sure nothing's caught in the seal, and start again.
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