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:
- Turn off the dishwasher.
- Switch off the water supply to the dishwasher (if necessary).
- In case the problem isn’t related to regular maintenance, you can seek advice from Bosch or a local appliance repair service provider.
- 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
- 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.
- 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.
- 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.