Anyone with a Bosch dishwasher will at some point experience a problem. Fortunately, Bosch self-diagnostics are accurate, and most times once we address the error, you won’t see the alarm again for some time! I like to think the error codes point to a single problem, but experience has taught me to think differently. You may find that after you repair one problem, another one follows. Don’t be discouraged because it happens like that when a problem with, say, your drain pump, causes a backup of debris in the drain hose that you weren’t aware could cause a problem.

Let’s also say you have a drain problem and you find the drain pump failed and no longer drains. During the time the pump gradually fails, debris begins to build up inside the drain hose, and eventually prevents wastewater from passing through. The drain pump continues to work hard and do its job until it finally stops. Let’s say you discover the pump is worn-out, so you replace it with high expectations, only to realize the water still isn’t pumping out like it should.

Scenarios like that are why when you’re troubleshooting, consider every possibility for accurate problem solving. In that scenario, the drain pump is slowly failing (which they do from time to time) and can’t drain the wastewater, but also debris is building up inside the drain hose, which makes the problem even worse!

When the pump fails, if I know Bosch, then you’ll probably received a few error codes related to a drain issue, which is great! However, it’s possible the codes may take you in another direction, veering away from the real problem. When this happens, it’s good to know how your machine works and why you might see erroneous codes, because your machine is doing what it does and doing its hardest to help you. Learning about the most common Bosch dishwasher error codes is good and it’s where we’re going to start today.

Note: use the codes here as a guide only. They should get you close to the cause of the problem, but troubleshooting is the best way to know for sure. Also, keep in mind that depending on your model, some codes won’t apply to your machine as they change from time to time without notice.  

If your machine doesn’t use a full LCD display and can’t display alphanumeric codes, find the single letter fault codes at the end of this list.

E01 – There’s a heating issue detected, and most likely caused by a bad internal heater. Also check for correct water level. If it’s too low, the control locks out the heater to protect it.

E02 – Temperature Sensor (thermistor)

E03 – Not sensing water fill (water inlet valve)

E04 – Water switch faulty (water level switch)

E05 – Water overflow (flood mode) (float switch or water inlet valve)

E06 – Aqua sensor fault (aka Turbidity Sensor)

E07 – Not drying (vent fan or heater/fan)

E08 – Water level issue at heater (water inlet valve)

E09 – Flood mode (not draining, check drain pump and filters)

E10 – Lime scale built-up on heater surface (try Dishwasher Magic to clean or replace heater)

E11 – Thermistor fault (this is an error code for an older Bosch dishwasher)

E12 – Lime scale built-up on heater surface (try Dishwasher Magic to clean or replace heater)

E13 – Water temperature error (most commonly occurs if water temperature exceeds 75C or 167F)

E14 – Water flow meter failure

E15 – Leak detected (float switch at bottom near sump is activated)

E16 – Uncontrolled water flow (water inlet valve stuck open)

E17 – Water pressure too high (flow meter error, water inlet valve)

E18 – No water flow detected flowing into machine (water supply, kinked hose)

E19 – Recirculation valve failure inside heat exchanger (found in European units with cold water supplied at inlet)

E20 – Wash motor failure (circulation pump or clogged system at sump)

E21 – Drain pump failure (clogged pump or filter, impeller damage)

E22 – Dishwasher filter in sump is blocked (clean and check operation)

E23 – Drain pump is blocked or clogged (drain pump failure)

E24, E25 – Not draining (drain hose clogged or kinked, drain inlet in sump, drain pump)

E26 – Reserved

E27 – Improper input voltage to unit (usually caused by a voltage drop)

E28 – Turbidity sensor (see E06)

LETTER FAULT CODES

A or B – Water leak detected (check float and bottom near sump for water)

C – Circulation pump error (wash motor)

D – Electrical issue from main control to wash motor (possible motor relay or triac)

E – Diverter valve error (diverts water to top rack)

F – Long fill error (check water supply or water inlet valve)

G – Diverter triac fault (check main control)

H – Not heating (heating element, thermo, or board)

K – Thermistor fault (NTC)

O – Pressure sensor error (water level)