This make publishes more than most
Seventy-two conditions on this site come from the manufacturer’s own support material, with the label it uses and the meaning it gives. That is unusual. Several makes we work on publish nothing at all for refrigeration, and the difference shows in how a call starts: with a Bosch, the number on the display is a real beginning rather than a rumor from a forum.
The same condition has more than one label
An older dishwasher shows a two-digit code, a newer one a four-digit code, and a machine with no display at all shows a pattern of lights. All three can describe the same thing – water not leaving the machine – and none of them names the part. E15 is the clearest example: it is the leak-protection system reporting water in the base pan, and the water is in the base pan for one of five ordinary reasons, only one of which is a broken component.
A code names a circuit, not a part
This is the half that gets lost. A code says which reading the control did not like. It does not say whether the sensor is wrong, the thing it is measuring is wrong, or the wiring between them is wrong, and those are three different repairs at three different prices. That is what the on-site diagnostic settles, and it is why we do not quote from a code alone.
What to do while the code is still on screen
Photograph the display, note the model number from the tag, and note what the machine was doing when the code appeared – part-way through a cycle, at the start, or after a power cut. Those three facts turn a code into a diagnosis. If the machine has no display, count the flashes: the pattern is the code, and we can read it.
When there is no code at all
Plenty goes wrong quietly. A refrigerator that cools unevenly, a dryer that takes two cycles, a hood that runs at one speed – none of that reports a number, and it is what the symptom pages are for. A machine behaving oddly with a clear display is not a machine with nothing wrong.