Bosch E03 fault codewhat it means and how to fix it
The condensate tank is full. Bosch attach their own scope warning to this one, which is unusual and useful.
Before you start
What E03 means
The simplest of Bosch’s five published codes, and the only one where they bother to tell you which machines it can apply to. Their wording is: "An E03 error suggests that the condensate tank is full. Emptying the condensation unit is essential after every cycle, so remember to do this before drying a new load." And then, unusually, a disclaimer on the page itself — "only for condenser and heat pump dryers."
That caveat is worth more than it looks. A vented dryer has no condensation container because it blows the moisture outside, so it cannot show this code, and a reader with a vented machine who lands here knows immediately they are in the wrong place. Very few manufacturers scope their code pages this way. The instruction to empty after every cycle is also worth taking literally rather than as a counsel of perfection.
A full load can put several litres of water into that container, all of it out of your washing, and a container that was fine yesterday may be full today if the washing went in wetter. The machine stops rather than overflowing, which is the behaviour you want, and emptying it is the entire fix.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| The container is full | The straightforward and overwhelmingly common reason. Not a fault at all — the machine has stopped rather than overflow, and emptying the container resolves it completely. | Common |
| The container is not pushed fully back in | A container sitting slightly proud does not register as seated, so the machine behaves as though it were still full. Push it until it stops rather than until it looks right. | Common |
| The washing went in wetter than usual | Not a fault either, but it explains a container that suddenly needs emptying more often. A lower spin speed on the washing machine sends more water to the dryer, and all of it ends up here. | Occasional |
| The container filter is soiled, or the drain hose is kinked or blocked | Bosch’s own troubleshooting row for the container symbol lists these alongside a full container: "The filter for the condensation tank is soiled", and, on a machine plumbed to a drain, a water outlet hose "not connected correctly, or is kinked or trapped" or blocked, which they say to rinse with tap water. | Occasional |
| The level sensor or the pump has failed | Where an empty, correctly seated container still produces the code, the machine has lost the ability to detect or move the water. This is the only version that needs an engineer, and it is uncommon. | Rare |
What to try yourself
Pull the condensation container out slowly, keeping it level and upright — Bosch warn there is no screw cap on it and the water may be warm — and pour it away in the sink.
Push it fully back in until it seats. Bosch’s own prompt for the container pictogram is to "Empty and insert the condensation container" — the inserting is half the instruction.
Restart the programme. On a machine that had simply filled up, that is the whole job.
Get into the habit of emptying it after every cycle. Bosch describe this as essential rather than advisable, and it prevents the code entirely.
If the code persists with an empty, properly seated container, check the two things Bosch list next: the filter in the container (on SelfCleaning models it is cleaned automatically when you empty the container, but Bosch say to check it regularly and clean it under warm running water if it is dirty) and, if the machine is plumbed to a drain, that the outlet hose is not kinked, trapped or blocked. Only after that does it point at the level sensing, and a call.
Get a qualified appliance engineer to look at your Bosch E03
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£160
Time on site
5 minutes
Nothing at all in nearly every case, since emptying a container is not a repair. A level sensor or pump with labour is the rare upper end. Bosch publish no dryer call-out charge.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Bosch fault codes
- E01Get it checkedA blockage in the filter or heat exchanger. Bosch publish an eleven-step fix for it that most of their current machines cannot accept.Related: same brand
- E06Get it checkedBosch say the lint filter is blocked. Their own page for this code then reprints the text for a different code, so their summary line is all the description that exists.Related: same brand
- E04Usually simple to fixYou have put too much in. Bosch give the most practical loading test in this whole category — a hand’s width above the washing.Related: same brand
- CrEUsually simple to fixNot a fault. The machine is asking you to run its care programme — and it is spelled two different ways depending on your model, which is why it is hard to look up.Related: same brand
- HotUsually simple to fixExplicitly not a fault. The machine is cooling your washing on purpose, and Bosch ask you not to interfere with it.Related: same brand
Own a Bosch tumble dryer? Save it and its codes come first next time.
Related guides
Common questions about Bosch E03
I have a vented dryer and I am seeing this code.
You should not be, and Bosch say so themselves — their page carries the disclaimer "only for condenser and heat pump dryers." A vented machine has no condensation container. If you are certain your machine is vented and certain of the code, check the code again, because one of the two is likely wrong.
How much water should it collect?
Several litres from a full load, which surprises people the first time they notice. All of it came out of your washing. If it is filling faster than it used to, the likeliest explanation is a lower spin speed on the washing machine rather than anything wrong with the dryer.
Can I plumb it into a drain instead?
On most models yes, and it saves the chore entirely. Keep the run short and avoid loops that hold standing water. Be aware it adds one winter failure mode a container does not have, which is the hose freezing if it runs somewhere cold.
Does the container have a filter?
On current SelfCleaning models there is a condensation container filter, and Bosch’s manuals describe it as cleaned automatically when you empty the container — so emptying it regularly does two jobs rather than one. They add: "Check the filter regularly and clean the filter if it is dirty", under warm running water, and a soiled container filter is one of the causes they list for the container symbol.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer support portal
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.