Bosch E79 fault codewhat it means and how to fix it
The i-DOS automatic dosing pump is blocked. Only machines with i-DOS can show this, and you can switch the feature off and carry on meanwhile.
Take care
What E79 means
E79 only exists on machines fitted with i-DOS, Bosch’s automatic dosing system, which is a Series 8 and upper Series 6 feature rather than something every Bosch has. Instead of you putting detergent in the drawer for each wash, i-DOS holds a reservoir of liquid detergent and a small pump metres out the right quantity for the load it has weighed. E79 is that pump reporting itself blocked.
What makes this code worth a page rather than a line is the remedy BSH publish alongside it, because it is one of the very few places in this corpus where the manufacturer offers a genuine workaround rather than a repair. They tell you to clean the detergent drawer, and then they say something more useful: you can deactivate intelligent dosing and dose manually until it is fixed. That turns a machine with a broken feature into a machine that works normally while you wait for a part, which is a materially different situation from most codes.
The blockage itself is what you would expect from a small pump handling liquid detergent. Concentrated detergent dries to a gum, and thickened residue in the dosing channels and around the pump is what stops it. It is a maintenance fault more than a component failure, and it responds to cleaning.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Dried detergent in the dosing channels | Liquid detergent thickens as it dries and gums the narrow passages of the dosing system. The commonest cause and the one cleaning fixes. | Common |
| Wrong product in the i-DOS reservoir | The system is designed for liquid detergent. Powder, gel capsules emptied in, or thick softener sit in the channels and set. | Occasional |
| Dosing pump failed | Where the channels are clean and the code persists. A part, and the reason BSH tell you how to keep washing meanwhile. | Occasional |
What to try yourself
Deactivate intelligent dosing in the machine’s settings and dose detergent by hand for the time being. BSH publish this as part of the remedy, and it means you are not without a washing machine while you sort the rest out.
Switch off at the socket, then take the detergent drawer out completely — most pull out and release with a catch once fully extended.
Wash the drawer and its inserts in hot water and dry them. Look particularly at the narrow channels rather than the visible bowls, because that is where thickened detergent sets.
With the drawer out, look into the housing with a torch and clean the visible passages. Do not push anything rigid into the dosing outlets — a soft brush and hot water only.
Refit the drawer, re-enable i-DOS and run a short programme. If the code returns immediately, leave i-DOS off and book it. BSH tell you to contact service at that point rather than offering a second thing to try.
Get a qualified appliance engineer to look at your Bosch E79
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–£190
Time on site
35 minutes
Nothing if cleaning clears it. A replacement dosing pump is roughly £90 to £190 fitted, and the option of running with i-DOS switched off means it is not an urgent booking.
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
- E33Usually simple to fixToo much foam. Bosch tell you to reduce the detergent, and on a machine with i-DOS automatic dosing that advice needs adapting.Related: detergent and foam
- E18Get it checkedThe machine could not pump out in the time allowed. Bosch point at the filter and the drain hose, and warn that the water you are about to release may be scalding.Related: same brand
- E17Get it checkedProblems with the water connection: tap, kinked hose, blocked inlet filter or low pressure. Bosch’s AquaStop hose has a filter at the tap end most owners do not know about.Related: same brand
- E23Stop — call an engineerWater has been detected in the base of the machine and the AquaStop system has cut in. Bosch say to turn the tap off immediately and stop using it until it is repaired.Related: same brand
- E32Usually simple to fixAn unbalanced load, and Bosch headline it as the machine flashing "end" at the end of the programme. They state outright that this is not a fault.Related: same brand
- E06Get it checkedThe pump is blocked by something that got into it, or the outlet hose was kinked when the machine was last moved. Both are owner jobs.Related: same brand
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Related guides
Common questions about Bosch E79
Can I keep using the machine?
Yes, and BSH say so. Turn intelligent dosing off in the settings and put detergent in the drawer yourself as you would on any other machine. It is one of the only codes in the Bosch set with a published workaround that leaves you with a fully working appliance.
Does my machine even have i-DOS?
Only some do. It is a Series 8 feature and appears on part of the Series 6 range, and it is obvious when you have it — there are large refillable reservoirs for liquid detergent and softener rather than a simple drawer, and the machine doses itself. If yours does not have that, E79 is not your code and something has been misread.
What detergent should go in the reservoir?
Liquid detergent, and nothing thicker. The system meters small quantities through narrow channels, so anything that sets or has undissolved solids in it will eventually block it. This is the cause of the code far more often than the pump itself failing.
How do I stop it happening again?
Clean the drawer and the reservoirs periodically rather than waiting for a code, and do not top a reservoir up with a different product without rinsing it first. Mixing thickened detergents is a good way to end up with something in the channels that neither product would have produced alone.
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
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.