What this code means, briefly
The short reading of E03 on a Bosch dryer: the condensation drainage hose is blocked or kinked. It will run, but the water it condenses has nowhere to go, so stop until the hose is clear. Most of what follows is diagnosis rather than repair, and the repair end of it is a technician job.
Error codes
Reference| Code | Meaning |
|---|---|
| E03 | Error code E03 on Bosch dryers indicates that the condensation drainage hose is blocked or kinked. |
What you actually observe
- The water container fills although the machine is plumbed to drain — When the hose cannot take the water, the machine falls back on its reservoir.
- The pump runs on and on without the level dropping — The control is trying to drain and getting nowhere, which is what it eventually reports.
- NEAR MISS — the pump is silent and no water moves at all — That is a pump or its circuit rather than a restriction, and the checks below separate the two.
What triggers E03, most likely first
- A kink where the hose passes behind the machine — First because it is the commonest and it needs no tools: the hose is bent against the wall when the dryer is pushed back, and a bend that looks gentle from the front can be shut at the back.
- A blocked filter, trap or pump inlet — Debris collects at the narrowest point in the path, and the restriction grows until the control cannot empty within its time limit.
- A failing drain pump — Last of the likely causes: a pump that is worn moves water slowly, but the four cheaper causes above produce the identical code and have to be cleared first.
What to check first, second, third
- Pull the machine forward and look along the whole hose run — You are looking for a crush behind a foot and a tight bend against the wall.
- Look at the whole visible run of the hose — A kink behind the appliance is the single most common cause, and it is found by eye in a minute.
- Listen for the pump during the drain phase — A pump you can hear turns the problem into a restriction; silence points at the pump or its circuit.
What an owner can safely do
- Straighten the hose over its whole run and check the outlet height — Pull the dryer clear of the wall, remove every tight bend, and route the hose without a loop above the drain point.
About 20 min
- Clean the filter and trap and refit them squarely — Expect standing water: have a shallow tray and a towel ready before opening anything.
Tools: shallow tray, towelsAbout 20 min
- Test the drain point with a jug of water — A standpipe that backs up on a jug will certainly back up on a full appliance.
Tools: jugAbout 5 min
- STOP HERE if the path is clear and it still will not empty — The pump and its valve sit inside the machine, behind a panel and next to standing water.
Safety first
Safety
Switch the dryer off at its breaker before removing a panel; stored charge remains after the power is off. Keep the lint paths clear: restricted airflow plus heat is the one condition on a dryer that is a real fire risk. On a gas model, if you smell gas, leave and call the gas utility from outside.
When to call a technician
Call once the hose is straight, the filter and trap are clean, the standpipe takes water and the appliance still will not empty.
Nearby codes on the same appliance
Scope of this reading
What is written here is generalized to the Bosch dryer line rather than to a single family. Deliberately absent: connector positions, wiring colours, part numbers and the service sequences for your particular build, all of which vary across the line and belong in the manual for your model. If a model-specific page for this code has been published it is linked from the index below, and that page outranks this one for your unit.
Links: - [Bosch dryer error codes](/blog/bosch-dryer-error-codes)
The code index
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
