Siemens [E20] fault codewhat it means and how to fix it

Siemens give E20 as the appliance reporting an error with the rinsing circuit, and name a fault in the circulating pump as the possible cause. The first thing to get straight is which pump that is, because a dishwasher has two and confusing them wastes money. The drain pump empties the machine at the end of the cycle and is the one people meet, because it jams on broken glass and it is reachable from inside the tub. The circulation pump is the other one: it takes the water in the sump and drives it up through the spray arms under pressure, and it runs for almost the whole programme. It is the component that actually washes your dishes. Everything a dishwasher does to a plate is done by water arriving hard enough to knock food off it, and the circulation pump is what supplies that force.

So the symptom that goes with this code is not standing water — the machine will usually still fill and still drain perfectly well. It is a cycle that runs, or tries to, and leaves the load essentially untouched, sometimes with the detergent tablet still sitting undissolved in its compartment. That last detail is the useful one, because a tablet that has not dissolved is direct evidence that water was not being thrown around inside the cabinet.

There is one important caveat about this code specifically. E20 appears on the Siemens website and in no BSH manual we have read — the two-digit Bosch and Neff manuals stop at E:27 and dispose of everything else through a single catch-all entry covering E:01 to E:30, which is where E20 falls, and the long-form manuals do the same with a catch-all running from E:01-00 to E:90-10. So the code is real and the manufacturer describes it, but the description is a sentence on a web page rather than a documented fault table, and Siemens hedge it themselves with "could be caused by". Treat the circulation pump as the leading candidate rather than a diagnosis.

1. 1

   Switch off at the socket, then take out the bottom basket and twist out the filter assembly. Separate the coarse cup from the fine mesh and wash both under a hot tap.

   Let a machine that has just stopped mid-programme cool before you start. BSH warn that water inside can be hot enough to scald, and the residue standing over a blocked filter is strongly alkaline.
2. 2

   Take both spray arms off — they usually unclip or unscrew by hand — and hold each up to the light to check every jet is open. Clear any that are furred up with a cocktail stick, then check both arms spin freely.

3. 3

   Look into the sump recess with a torch before putting a hand near it, and remove anything hard you find. This is the only part of the circulation path an owner can reach.

   Broken glass is the commonest thing in there. Look first, and use a cloth rather than bare fingers.
4. 4

   Refit everything so the filter locks and the arms turn, then run a short hot programme with the machine empty and listen. A healthy circulation pump makes a steady rushing noise; near silence with the programme still counting down is the symptom that goes with this code.

5. 5

   If it comes back, stop and book someone. This is the point at which the remaining candidates are all behind the outer casing, and Siemens’ own position on a code that persists is to contact their service rather than continue.