Bosch Washer Error Codes List: Every Code Explained

Every Bosch washer error code we could verify against Bosch's own documentation — what it means, what usually causes it, and the first fix to try — in one table. Codes differ between model series, so treat your model's tech sheet as the final word.

How to read and retrieve error codes on Bosch washers

Bosch washers include a service test program (selector position + button combination per the service manual) that shows stored errors and runs each component test in sequence.

The complete Bosch washer error code list

How to reset / clear error codes on Bosch washers

Bosch washer codes clear by cancelling the program (turn the selector to Off, wait a few minutes) followed by a fresh program start; persistent faults need a power cycle of several minutes. A code that returns at the same cycle stage is an active fault.

How to diagnose any Bosch washer code

Work the problem in this order: (1) write the code down exactly as displayed — photograph it, because opening the door or pressing pause can clear it; (2) ask what the machine was doing when the code appeared — filling, washing, draining, spinning or heating points straight at the fault family; (3) run the external checks for that family first: taps and inlet screens for fill codes, the pump filter and drain hose for drain codes, load size and levelling for balance codes, the door seal and latch for lock codes — these cure the majority of washer codes without a single part; (4) clear the code and run the shortest cycle that exercises the same function (a rinse-and-spin for drain faults, a small wash for fill faults) while you watch — a code that returns in the same phase is an active fault, not a glitch; (5) only then test or replace the component the code monitors, and re-test under the same conditions that produced the fault. Skipping to step 5 is how good parts get replaced for a clogged filter.

How Bosch numbers its washer codes

Bosch washer codes are numbered by the system they monitor, and the numbering itself is a first diagnostic: the teens cluster around water in and out (fill, drain, leaks and aqua-stop events), the twenties around the door and lock, the thirties around motor and drive sensing, and higher numbers around electronics and communication. The letter matters too — E and F prefixes on different Bosch generations can mark the same fault family, which is why the table notes display variants inside the entries. As always, your model's programme chart and manual define the exact list for your series.

The most searched Bosch washer codes, in detail

E18 — The washer is not draining

E18 is Bosch's drain fault. Bosch's support pages tie it to a blocked pump or a blocked or kinked drain hose, and its manuals state it plainly: the drain pump is blocked, or the drain hose or drain pipe is blocked. The machine is left holding water it cannot pump out, so the cycle cannot finish. Bosch says owners can solve this in many cases by cleaning the pump and checking the drainage path.

Most likely cause: Blocked drain pump — Debris collects inside the pump until it cannot move water. Bosch's procedure stresses the impeller must be able to rotate — if it cannot, the pump is blocked.

First check: Close the water supply first, then switch the machine off and pull out the main plug, as Bosch's procedure starts.

If it keeps coming back: E18 returns when the restriction was only partly cleared: residue in the pump housing or on the cover thread, a filter insert still stuck, or a blockage in the siphon rather than the machine. It also returns if the cover was not screwed fully home, and when the pump itself is failing — a defective pump can pass a quick clean and fail again under a full drum.

E23 — AquaStop has been activated: there is water in the base trough

E23 is Bosch's leak-protection fault, listed with F23 as 'Aquastop activated.' Bosch manuals state it directly: there is water in the base trough, the appliance is leaking — turn off the tap, call customer services. On AquaStop Plus models, Bosch's manual says the feature detects water leaks on the internal base, shuts down operation and pumps out water so it cannot reach the floor. The machine has found water where no water should be, and stopped to protect your floor. Bosch is explicit: this fault cannot be rectified by itself.

Most likely cause: Water leaking into the base trough — The fault itself, as Bosch states it: the appliance is leaking and leaked water has collected in the base trough, which the protection responds to.

First check: Turn off the water tap immediately — Bosch's stated remedy the moment E:23 appears — then switch off and unplug the appliance.

If it keeps coming back: E23 returns when only the symptom was dealt with and the leak was not found: water reaches the base trough again on the next fill or pump-out and the protection re-activates. Intermittent hose and seal leaks are the usual story — a connection that only weeps under pressure, or a seal that only leaks with a full load, can pass a quick look and refill the base over a few cycles. Recurring detergent overdosing can do the same.

E27 — Pressure sensor faulty

E27 / F27 is a sensor fault, not a blockage you can clean out. The pressure sensor belongs to the water level measuring system — the system the control relies on to know how much water is in the appliance. Bosch's position is blunt: the fault cannot be rectified by itself, and the owner is directed to contact customer service and arrange a service appointment. There is no pump to clean and no hose to straighten, because the part Bosch names as faulty is the sensor itself.

Most likely cause: The pressure sensor itself is faulty — The cause Bosch states for this code, in so many words: 'Pressure sensor faulty.' Bosch lists no user-side cause or remedy for it.

First check: Write down the exact code first — E27/F27, not the code you assume — because Bosch's sensor codes sit side by side.

If it keeps coming back: If E27 returns after a restart cleared it once, Bosch's own framework explains it: the first appearance may have been a one-off, but a fault that occurs again and persists is a standing defect. Because Bosch names the sensor itself — not a filter, hose or cover — no missed maintenance step explains the return; the code keeps coming back until the faulty sensor is replaced.

E36 — Drain pump is blocked

E36 is the newer Bosch drain fault family, printed with suffixes. E:36 alternating with -10 covers a group: the outlet hose is connected too high, kinked or trapped, or extended impermissibly; the drain pipe or outlet hose is blocked; the drain pump is blocked or the pump cover is not installed correctly; and detergent dosage is too high. E:36-25 and -26 are narrower: drain pump blocked — clean the drain pump.

Most likely cause: Drain pump is blocked — The headline cause, and the only one Bosch lists for -25 / -26: debris in the pump stops it moving water. Bosch notes a foreign object in the pump also causes banging or rattling noises.

First check: Read the full display, suffix included: -10 points at hose installation, drain pipe, pump cover and detergent dose as well as the pump; -25 / -26 points at the pump alone.

If it keeps coming back: E36 returns when the blockage was not the whole story: dirt left in the housing, a filter insert still stuck, a cover screwed in short of fully home, or a restriction in the drain pipe or at the siphon. The -10 group has two repeat offenders — an outlet hose still too high or kinked behind the machine, and detergent dosage staying too high. Note which suffix returns: -25 / -26 again means the pump; -10 again means work the whole group.

Less common and model-specific codes

Search data shows owners also meet these codes on Bosch washers: A02, C8, E63, F8, OE, UE. They are not part of the core code list Bosch publishes for most models — several are series-specific, abbreviated display readings, or codes carried over from a sister platform — so we do not publish meanings for them rather than guess. Treat them by symptom: note what the machine was doing when the code appeared (filling, draining, heating, spinning), run one full power cycle (5 minutes off), and if the code returns, match the symptom to the closest documented family in the table above and check the tech sheet stored inside your machine for the model-specific definition.

Related guides

Facts on this page were checked against manufacturer documentation: www.bosch-home.com · www.bosch-home.com · www.bosch-home.com · www.bosch-home.ca · washingcodes.com · www.manuals.ca · 1library.net