Bosch Troubleshooting Guide: Common Dishwasher Error Codes

bosch dishwasher error codes

Bosch dishwashers rank near the top for reliability.

Yet even the best machines throw cryptic error numbers when something goes wrong.

But don’t panic: those codes are breadcrumbs the appliance leaves so you can narrow the fault before calling a technician (or spending Saturday on YouTube).

Below you’ll find three of the most common Bosch errors explained in plain English.

Bosch Error Codes - Why do they pop up?

Your dishwasher could run into dozens of problems over time.

From your door-locking mechanism to problems with your PCB, dishwashers have certain problems with certain error codes that you need to understand before calling a technician.

Why?

Because understanding the problem yourself also means that you can entirely skip a technician visit and fix the problem yourself.

One of the best ways to ensure you understand the problem is to refer to the machine manual that you receive with your dishwasher.

In certain instances, these error codes can also change from time to time – and Bosch will update that on their website.

However, to get a detailed overview of the current error code meanings for Bosch dishwashers, we’ve explained them further below. 

What to do when an error code pops up?

For most of the error codes that pop up on your dishwasher appliance, Bosch (officially) recommends the following steps:

  1. Turn off the dishwasher.
  2. Switch off the water supply to the dishwasher (if necessary).
  3. In case the problem isn’t related to regular maintenance, you can seek advice from Bosch or a local appliance repair service provider.
  4. Refrain from using the dishwasher until the problem is resolved. 


It’s always helpful to ensure that your dishwasher doesn’t have any water pooling in the bottom of the base plate.

One of the best ways to resolve that is to tilt the dishwasher at a 45-degree angle. This allows the water to drain when the dishwasher is switched off.

Error E15 – “AquaStop activated” (water in the base pan)

What it means: Bosch’s AquaStop system sits under the tub; if water leaks into that tray, it triggers a float switch, locks out the programme, and forces the drain pump to run non-stop.

Quick checks

1. Look for leaks around the door seal and inlet hose.

2. Tilt test: disconnect power, slide the dishwasher forward, and carefully tilt it 30–45 degrees to one side – if a cup or two of water dribbles out, the float will reset once the tray dries.

3. Restart after an hour; if E15 returns, the leak is active.

When to call in help

  • Persistent drips from the circulation pump or a cracked tub require parts, and fishing a dishwasher out of a tight kick-space is easier with two people.
  • If you find suds in the base tray, someone may have used regular dish soap; you’ll need to rinse the cavity thoroughly before restarting.

Error E24 – “Check drain” (machine can’t empty water)

What it means: E24 usually flags slow or stalled drainage. Bosch tech bulletins say the control board sets the code when the pressure sensor reports more than 30 seconds to empty the sump. Homeowners often confuse it with a fill fault because the machine pauses early in the cycle.

Quick checks

  • Filter first: twist the round micro-filter, lift it out, and clear food sludge.
  • Drain hose: Detach the hose under the sink and run water through; kinks or a blocked garbage-disposal nipple are typical culprits.
  • Siphon loop: make sure the hose arches higher than the disposal inlet; without that high loop, wastewater can backflow and trigger E24.

DIY fixes that work

  • A turkey baster can suck standing water from the sump so you can examine the impeller.
  • If you hear the pump buzz but see no flow, a broken glass shard may be wedged in the impeller fins—remove the safety cover, tweeze it out, and re-test.

Stop here and book a service if

  • The drain pump hums loudly or rattles after clearing the hose (bearings may be shot).
  • You can’t locate an obstruction, yet E24 reappears on the next cycle.

Error E22 – “Filter system blocked”

What it means: E22 is a close cousin of E24. Instead of a full-drain failure, the machine detects standing water in the filter cavity when it expects that area to be dry. Typically, the fine-mesh micro-filter or the plastic sump channel is packed with food particles.

Quick checks

  • Pull the micro-filter (it’s the grey cylinder under the bottom rack) and rinse under hot water until it runs clear.
  • Inspect the sump: shine a torch down the hole; remove pasta, fruit seeds, or stray labels that slipped past the filter.
  • Run a rinse cycle with the filter still out (machine empty) to flush crumbs.

 

Pro tips

  • Add a tablespoon of dishwasher cleaner crystals to the bottom before a hot “Auto” cycle; enzymes break down grease films that trap debris.
  • Teach the household to pre-scrape plates—Bosch designs its pumps for fine residue, not half a bowl of oatmeal.

Call a technician if

E22 persists after a full clean, and you hear the pump start-stop rapidly; that hints at a pressure-sensor fault or wiring issue behind the side panel.

Error E09 – Heating circuit fault (water stays cold)

When a Bosch dishwasher shows E09, it’s telling you the water never reached wash temperature. The control board monitors the heating loop and trips E09 when it sees less than a 2 °C rise in the first few minutes. Bosch’s UK help pages state it directly: the heating element is defective or its wiring has failed.

Checks you can do in 10 minutes

  • Run the tap hot at the sink first. Incoming water above 50 °C shortens heat-up time and sometimes clears the code.
  • Kill the power, pull the toe-kick off and look for a white crust on the round metal pump-heater: heavy limescale insulates the element.
  • Sniff for burning at the wiring plug – darkened plastic means the spade connector overheated.

DIY fixes that work

  • A kettle of 1-to-1 vinegar and water poured around the element (machine unplugged) dissolves surface scale; rinse and retry.
  • With a multimeter, check resistance across the heater pins: 16–20 Ω is normal. Infinite ohms means the element is open and needs replacing.

Call a technician if

  • The heater tests open-circuit, or you see leaks around the circulation pump body—the part comes as a sealed pump-heater unit.
  • E09 returns after descaling, and the machine now stops mid-cycle; that points to a control-board relay fault.

Error E06 – Door / optical sensor error

On recent models, E06 indicates the door-latch reed switch can’t see the magnet in the door, so the machine thinks it’s open even when latched. 

Older units use E06 for an optical “aqua sensor” that checks water clarity: both faults live in the same wiring branch.

Simple things first

  1. Close-and-push test: press firmly at the top centre of the door – if the wash starts for a second then stops, the latch is loose.
  2. Inspect the latch plate (two Torx screws in the stainless door edge). If it looks bent, loosen screws, realign so it meets the cabinet catch squarely and retighten.
  3. Wipe the optical port—a small clear window inside the sump—if your manual calls the part an “AquaSensor”.

When E06 sticks around

  • Replace the $15 reed switch (one clip, two wires) if rattling it makes the error flicker. 
  • If the control panel still shows E06 after a hard reset (breaker off 30 s), sensor wiring or the main board may be faulty—time for professional diagnostics.

Errors E16 and E17 – Fill-level problems

Bosch splits inlet issues into two codes:

Code

What it means

Typical cause

E16

Water keeps entering; the float switch says “overflow.”

Inlet valve stuck open or hose not seated

E17

Water pressure too high/flow meter cannot count pulses correctly

Supply pressure above 90 psi or flow meter faulty

Bosch’s own support page confirms that both errors point to the water-inlet path.

Quick checklist

  • Is the inlet hose kink-free? A partial kink can whip straight when the machine fills, then pinch again, tricking the sensor.
  • Check the strainer at the tap end; grit holds the valve slightly open and triggers E16.
  • Measure supply pressure with a cheap gauge (that screws onto the cold-tap thread). Anything above 80 psi can trip E17; fit a $10 pressure regulator if needed.
  • Look for suds in the sump; foam lifts the float and mimics an overflow.

DIY fix

Turning the water tap off, then on while the machine is powered up may reset a sticky valve. If E16 returns instantly with the tap open only a quarter-turn, the valve inside the dishwasher has failed closed; for E17 that repeats even with low pressure, the flow meter likely needs replacing. 

Appendix – Complete Bosch Dishwasher Error-Code Reference

Code

Plain-English fault

First things to check

Likely DIY fix

Call a pro when…

E01 / E02

Control-board heating-relay fault

Power-cycle 30 s

None (board swap)

Code returns immediately

E03

Not enough water in tub

Tap fully open, hose kink?

Clean inlet screen

Still dry inside after reset

E04

Flow-sensor / circulation issue

Check for hard-water scale

Descale, run hot cycle

Pump hums but no spray

E05

Overfill float tripped

Look for suds or over-soap

Wet-vac, restart

Water keeps entering with door open

E06

Door-latch or optical sensor fault

Close firmly, wipe latch

Replace reed switch

E06 reappears after reset

E07

Zeolite drying-fan failure (CrystalDry models)

Listen for fan spin

Clear lint round fan grille

Fan silent or rattling

E08

Heat-pump motor defect

Listen for hum but no spray

None (pump unit)

Machine fills, then stalls

E09

Heater element open circuit

Ohm-test 16–20 Ω

Replace pump-heater

New heater tests good yet code stays

E10

Zeolite-chamber heater fault

Inspect wiring block

Reseat plug

Needs new heater if open

E11 / E12

Temperature sensor bad / heavy limescale

Descale element

Replace NTC sensor

Code repeats mid-cycle

E13

Incoming water above 75 °C

Turn off hot-tap pre-heat

Feed cooler water

Code shows even with cold supply

E14

Flow-meter can’t count pulses

Hose kink, low pressure

Straighten hose

Flow meter faulty

E15

Water leak into base tray (AquaStop)

Tilt 30° to drain

Dry base, find leak

Drip returns after two runs

E16

Inlet valve won’t shut

Debris in valve seat

Replace inlet valve

Water trickles in with power off

E17

Water pressure too high

Gauge over 80 psi?

Fit pressure regulator

Code stays at normal pressure

E18

Fill timeout (very low flow)

Tap fully open

Clean inlet screen

Supply under 10 L/min

E19

Heat-exchanger valve fault

Listen for click

Replace wax valve

Valve coil open circuit

E20 / E21

Heat-pump internal error / drain-pump blocked

Check pump cavity

Clear glass, coins

Pump rattles or seized

E22

Filter system blocked

Rinse micro-filter

Hot rinse plus cleaner

Pressure sensor still says “full”

E23 / E25

Drain-pump electronics / impeller jam

Does impeller spin?

New drain pump

Still dead after swap

E24

Can’t drain

Hose kink, disposal plug

Clear blockage

Pump hums loudly

E26

Diverter (water-switch) error

Spray arm fouled?

Free the arm

Diverter motor faulty

E27

Mains voltage too low

Check other appliances

Wait for supply to stabilise

Voltage normal yet code shows

E28

Turbidity (aqua) sensor dirty

Wipe clear lens

Run dishwasher cleaner

Sensor lens cracked

E30–E33

Safety or sensor-cluster faults

Hard reset, inspect wiring

Always professional work

4-digit service codes

Same faults as above but logged during self-test

Follow paired two-digit entry

See matching fix

Persist after full reset

Can you override an error code on a Bosch dishwasher?

A manual intervention like turning your dishwasher off and on could make the error code disappear… temporarily.

But these error codes originate for a reason.

Especially when the problems are serious.

This is why we don’t recommend overriding an error code on any kind of appliance – not just Bosch dishwashers.

You’ll also realise that your appliance doesn’t function properly during an error code. 

For example, you may notice watermarks on your glassware or residue on your plates and cups. These problems are common and could be solved with the help of either a technician or by a DIY expert.

Conclusion

We hope this guide was comprehensive and detailed enough for you to figure out a solution and fix your appliance.

Not only have we gone over what error codes you can get on your Bosch dishwasher, but have also provided you with the steps on how you can resolve them.

If you’re searching for an appliance repair professional in London, Georgi’s Services may be able to help.

You can also contact us with any questions or enquiries.

We highly recommend checking out our pricing too, so that you can get an idea of possible costs to repair your product.