✦ Updated for 2026 – All Models Covered
Bosch & Siemens
Dishwasher Error Codes
Click any error code below to jump straight to the cause, what went wrong, and exactly how to fix it — written by real repair technicians.
So your Bosch or Siemens dishwasher threw up an error code and now you don't know what to do. Totally normal — these machines run a self-check every single cycle and the moment something feels off, they throw up a code on the display. The good news? Most of them are things you can actually sort yourself without calling anyone out. We've put together every error code we know about, what they mean in plain English, and what you should try first before reaching for the phone.
🔴 BOSCH DISHWASHERS
Bosch Dishwasher Error Codes
Covers all Bosch Series 2, 4, 6, 8 – 300, 500, 800 Series and all SHPM / SHEM / SHE models
DIY Fix Possible
Moderate – Some skill needed
Call a Technician
👇 Click any code to jump to its fix:
⚡ How to Reset a Bosch Dishwasher (First Step for Most Errors)
1
Turn the dishwasher off using the On/Off button.
2
Head to the circuit breaker and flip the dishwasher's breaker off.
3
Wait a full 30 seconds before switching it back on.
4
Start a fresh cycle and see if the error returns. If it does, follow the specific fix for that code below.
E01
Control Board / Pump Circuit Failure
The main control board has detected a fault in the pump control circuit
What's Actually Going Wrong
The main control board's pump control circuit has thrown a fault. This can also cause the machine to stop taking in water entirely because the heater can't start without a proper water supply — and the machine knows it.
What to Try
- Do the full power reset (flip the breaker off for 30 seconds).
- If the code comes straight back, this one is beyond a DIY fix — the control board needs professional diagnosis.
⚠️ Bosch has locked down the programming of replacement power modules. You'll need a Bosch-authorised engineer to replace and reprogram the board. Trying to do this yourself will most likely result in a second dead machine.
E02
Heater Relay Fault on Control Board
The heater relay or the temperature sensor / thermistor has failed
What's Actually Going Wrong
The control board's heater relay has a fault. In some models this can actually be triggered by a bad temperature sensor (thermistor) rather than the board itself — so it's worth checking the sensor first before assuming the board is gone.
What to Try
- Power reset first as always.
- If the code returns, check the thermistor/temperature sensor wiring for damage or loose connections.
- Replacing the thermistor is relatively cheap and within reach for a confident DIY person.
- If that doesn't clear it, the control board itself needs replacing by a tech.
E03
Auxiliary Heater Relay / Water Inlet Valve
Auxiliary heater relay fault or water inlet valve needs replacing
What's Actually Going Wrong
Similar to E02, but this one hits the auxiliary heater relay. It can also be triggered by a dodgy water inlet valve that's not letting water in at the right rate.
What to Try
- Reset the power.
- Check the water inlet valve — if it's partially clogged or sticking, replacing it is a manageable repair.
- If the valve looks fine, a technician needs to assess the control board.
E04
Heating System Fault
Control board heating fault — needs professional diagnosis
What to Try
- Power reset and retry.
- If it comes back, contact Bosch or a certified appliance tech. This one needs specialist equipment to diagnose properly.
⚠️ Don't ignore E04 and keep running the machine — you risk burning out the heating element if there's an underlying electrical fault.
E05
Power Module Failure
Main power module on the control board has failed
What to Try
- Power reset as a first step.
- If the error persists, call a Bosch-authorised engineer — the module needs programming after replacement and this can't be done without dealer-level tools.
E06
Faulty Door Switch / Door Lock
The door latch or its switch isn't making proper contact
What's Actually Going Wrong
The dishwasher thinks the door isn't properly closed, or the switch that confirms the door is shut has gone bad. The machine won't run if it thinks the door is open — for obvious reasons.
What to Try
- Open and firmly close the door. Give it a proper push — sometimes the latch just needs seating properly.
- Check the door latch for any physical damage or debris blocking it.
- Inspect the door gasket — if it's swollen or warped, it might be preventing a proper seal.
- If the latch mechanism looks damaged, a replacement latch assembly is usually inexpensive.
E07
Drying Fan Fault
The drying fan motor has failed or is blocked
What to Try
- Power reset and run another cycle.
- Check if there's anything obstructing the fan at the rear of the unit.
- If the fan motor itself is burned out, it needs replacing — a moderate repair most comfortable DIYers can handle.
E08
Water Level Too Low / Flow Rate Issue
Not enough water is getting into the machine
What to Try
- Check the water supply tap under the sink is fully open.
- Inspect the inlet hose for kinks or blockages.
- Check the inlet filter (usually at the back of the machine where the hose connects) for limescale or debris — clean it out.
- Low household water pressure can also trigger this — try running the kitchen tap to check flow.
E09
Heating Element Fault
The heating circuit has a problem — dishes not getting clean or dry
What's Actually Going Wrong
The dishwasher's heating element isn't working correctly. This can mean dishes come out cold, greasy, or still wet. The element itself may have failed, or there's a wiring issue connecting it to the board.
What to Try
- Power reset first.
- Check wiring connections to the element if you're comfortable doing so.
- Test the element with a multimeter for continuity — if it reads open circuit, the element is dead and needs replacing.
💡 If you've been noticing dishes coming out cold or greasy for a while before the E09 showed up, the element has probably been failing gradually — don't put this repair off.
E10
Limescale on Heating Element
Heavy limescale buildup is causing the element to overheat and fail
What to Try
- Run a descaling cycle — put a dishwasher descaler or white vinegar in the bottom of the empty machine and run a hot cycle.
- Make sure you're regularly using dishwasher salt (for hard water areas this is especially important).
- If descaling doesn't help and the code keeps coming back, the element may be permanently damaged and need replacing.
💡 If you're in a hard water area, run a descaling tablet monthly to prevent this from coming back.
E11
NTC Thermistor / Temperature Sensor Fault
The temperature sensor is giving wrong readings or has failed
What to Try
- Power reset and re-run.
- Locate the NTC thermistor (usually near the sump), check the wiring for damage or corrosion.
- Test the sensor with a multimeter — if resistance readings are wildly off, replace the thermistor. It's a cheap part.
E14
Water Inlet Flow Sensor Fault
The flow sensor measuring incoming water has a problem
What to Try
- Check the inlet hose and supply tap — make sure water can flow freely.
- Check the inlet filter for debris and clean it out.
- If the sensor itself is faulty, it'll need replacing — this is a job for someone with a bit of appliance repair experience.
E15
Water in Base Tray – AquaStop Triggered ⭐ Most Searched
Water has leaked into the bottom tray, tripping the flood protection
What's Actually Going Wrong
Bosch's AquaStop system detected water sitting in the base tray beneath the machine. The machine shuts itself down to prevent floor damage. The water got there because something leaked — could be a hose connection, a seal, the door gasket, or the sump area.
What to Try
- Turn off both the machine and the water tap immediately.
- Pull the machine out from under the counter carefully.
- Tilt the machine gently backwards at about 45° — this drains the water from the base tray. Have towels ready because it will make a mess.
- Once drained, the AquaStop float should reset and the error should clear.
- Before pushing the machine back, find the source of the leak and fix it — otherwise E15 will be back within a few cycles.
💡 Sometimes the AquaStop float gets stuck even after the water is gone. Tilting the machine back further can free it. If you keep getting E15 with no visible leak, the float switch itself might be stuck — try gently pressing it down.
E17
Water Level Too High
More water than expected is in the machine — faulty valve or sensor
What to Try
- Check the water inlet valve — if it's not closing fully, water keeps trickling in even when it shouldn't. A sticking valve needs replacing.
- Check the flow meter / water sensor, as a faulty reading here can trigger a false E17.
- Reset the machine and retry — if the code keeps coming back, the inlet valve is the most likely culprit.
E20
Circulation Pump Electrical Fault
Electrical issue in the wash motor or circulation pump
What to Try
- Power reset as a starting point.
- If the code comes back with the machine making unusual sounds (buzzing, grinding), the pump motor is likely damaged and needs professional replacement.
E21
Blocked Circulation Pump
Something is jamming the wash pump impeller
What to Try
- Remove the spray arms and the filter assembly from the bottom of the dishwasher.
- Look down into the pump area — a bit of glass, a toothpick, a cherry stone — these are the usual culprits.
- Remove whatever's blocking it and check the impeller spins freely by hand.
- Reassemble and run a test cycle.
E23
Drain Pump Fault
The pump that removes dirty water isn't working right
What to Try
- Clean the drain filter — a really clogged filter puts excessive strain on the drain pump and can trigger E23.
- Check the drain hose for blockages or kinks.
- If the pump itself is faulty (making no sound at all during draining, or making a grinding noise), it needs replacing.
E24
Drainage Issue – Blocked Filter / Hose ⭐ Most Common Worldwide
Machine can't drain the dirty water — most common Bosch error
What's Actually Going Wrong
The dishwasher tried to drain but couldn't shift the water properly. Nine times out of ten it's a gunked-up drain filter, but it can also be a kinked drain hose or a blocked drain pump.
What to Try
- Take out the filter at the bottom of the dishwasher (twist and lift). Give it a proper scrub under the tap with an old toothbrush.
- While you're in there, check the drain pump housing for any bits of debris — bone fragments, glass, etc.
- Go around the back and check the drain hose — if it's bent, kinked, or squashed against the wall, straighten it out.
- Make sure the drain hose isn't submerged in standing water in the kitchen drain — it needs an air gap.
- Reassemble everything and run a rinse cycle to test.
💡 If you've just installed a new dishwasher and got E24 immediately, check whether the knockout plug in the garbage disposal drain has been removed — this is a surprisingly common oversight.
E25
Blocked or Jammed Drain Pump
A foreign object is stopping the drain pump impeller from spinning
What to Try
- Remove the drain filter and look into the pump area with a torch.
- Common blockers: small pieces of broken glass, toothpicks, olive pits, labels off jars — fish them out with tweezers or pliers.
- Check that the pump impeller can spin freely — if it's seized, the pump motor may be burned out and need replacing.
E26
Water Switch / Pressure Switch Fault
The water level sensor switch has failed or is stuck
What to Try
- Power reset as a first step.
- If it persists, the water level pressure switch needs to be tested — if it's sticking open or closed, it needs replacing.
E27
Low Mains Voltage
Not a machine fault — the electrical supply voltage is too low
What to Try
- Check if other appliances on the same circuit are working properly.
- Make sure the dishwasher is plugged directly into a wall socket — not through an extension lead.
- If you suspect a voltage problem, get an electrician to check the supply.
- Try unplugging and restarting the machine once the voltage is stable.
💡 E27 sometimes pops up in evenings when neighbourhood demand is high. If it only happens at peak times and goes away on its own, it's genuinely a supply issue — not your machine.
E28
Turbidity Sensor Fault
The sensor that measures how dirty the water is has failed
What to Try
- Power reset and test again.
- Make sure the filter is clean — a very dirty filter can sometimes cause dirty water to cloud the sensor lens.
- If the sensor itself is faulty, it needs replacing — this is a moderate repair.
🔵 SIEMENS DISHWASHERS
Siemens Dishwasher Error Codes
Covers all Siemens iQ300, iQ500, iQ700 and all SN / SX series models
👇 Click any code to jump to its fix:
⚡ How to Reset a Siemens Dishwasher
1
Press and hold the Start button for around 3–5 seconds to cancel the current cycle.
2
Turn the machine off using the On/Off switch.
3
Disconnect from power at the plug or breaker for 30 seconds.
4
Switch back on and start a fresh cycle to see if the error clears.
E14
Water Flow Sensor / Filling System Fault
The flow sensor isn't reading water intake correctly
What's Actually Going Wrong
The water protection system has kicked in because either the filling system has a fault or the water supply isn't right. The flow sensor that monitors how much water is coming in is giving a reading the machine doesn't like.
What to Try
- Make sure the tap under the sink is fully open and water pressure is decent.
- Check the inlet hose at the back of the machine — make sure it's not kinked or squashed.
- Look at the corner valve and inlet hose filter for any blockages — clean if needed.
- If the code keeps coming back after all that, the flow meter itself likely needs replacing.
E15
Water in Base Tray – Flood Protection Active ⭐ Most Common
Water detected in the drip tray at the bottom of the machine
What's Actually Going Wrong
Same concept as the Bosch E15 — water has found its way into the base tray and tripped the flood protection float. The machine shuts down to stop floor damage. Something has leaked — a hose, a seal, or the door gasket.
What to Try
- Turn off the water tap immediately.
- Pull the machine out and tilt it backwards at roughly 90 degrees (have towels ready) — this drains the base tray and should reset the float.
- Once the E15 clears, find and fix the source of the leak before running another cycle.
💡 A stuck AquaStop float is a known quirk on Siemens machines. If you've drained the tray and the error won't clear, tilting the machine more aggressively usually frees the float.
E16
Water Filling Spontaneously / AquaStop Fault
Water is entering the machine when it shouldn't be — likely a valve fault
What's Actually Going Wrong
The machine is taking on water when it shouldn't be — usually because the inlet valve isn't closing properly. Overdosing on detergent can also cause excessive foam that tricks the sensors into thinking there's too much water.
What to Try
- Check you're using the right amount of dishwasher detergent — too much causes foam buildup that can trigger this.
- Turn off the water supply and reset the machine.
- If it keeps happening, the AquaStop or inlet valve needs professional assessment.
E17
Water Pressure Too High / Flow Sensor Fault
Incoming water pressure exceeds what the flow sensor expects
What to Try
- Check your household water pressure — if it's genuinely too high (common in some areas), a pressure reducer on the supply line can help.
- Check for a faulty solenoid valve, damaged AquaStop hose, or leaking seals — any of these can cause water to get where it shouldn't.
- Tilt the machine to drain the base tray if water has pooled there.
- If the flow sensor is reading incorrectly, it'll need replacing.
E18
Water Inlet Fault – Not Enough Water
Insufficient water getting into the machine during the fill cycle
What to Try
- Open the supply tap fully if it was partially closed.
- Check for kinks or blockages in the inlet hose.
- Inspect the inlet filter at the back of the machine — limescale and debris love building up here.
- If water pressure in your home is generally low, this may keep happening — a plumber can assess whether a booster is needed.
💡 Important: If E18 appears, let the machine finish on its own — do NOT switch it off mid-cycle. The machine handles this error automatically and cutting the power can make things worse.
E19
Dispenser / Detergent Compartment Fault
The rinse aid or detergent dispenser isn't working correctly
What to Try
- Check that the dispenser door opens freely — sometimes dried detergent gums it up. Clean it out thoroughly.
- Reset the machine and try again.
- If the dispenser mechanism itself is broken, it may need replacing — or it could be an electronics issue requiring a tech.
E20
Thermostat / Temperature Sensor Fault
The thermostat is reading the wrong temperature or has failed
What to Try
- Switch the machine completely off and back on — sometimes a temporary glitch causes this.
- If the code persists, the thermostat or NTC sensor likely needs replacing — a fairly straightforward part swap for most repair folks.
E21
Rinse / Circulation Pump Fault
The wash pump isn't running properly — possible blockage or motor failure
What to Try
- Remove the filter and check the pump area for any blocking debris.
- Make sure the pump impeller can spin freely by hand.
- If the pump motor is burned out (no sound or grinding sound during the wash cycle), it needs replacing.
E22
Blocked Filter ⭐ Most Common Siemens Error
The filter at the bottom of the machine is clogged with food and grease
What's Actually Going Wrong
The filter that catches food particles during washing hasn't been cleaned in a while (or possibly ever) and it's now so clogged that water can't flow through it properly. This is the easiest error to fix yourself.
What to Try
- Open the dishwasher and remove the bottom rack.
- Twist and lift the filter assembly out of the floor of the dishwasher.
- Take it to the sink and scrub it under warm running water with an old toothbrush. Get all the grease and bits off.
- Rinse it well and push it firmly back into place — make sure it clicks or seats properly.
- Run a short cycle to test.
💡 Clean the filter every 2–4 weeks to stop E22 from coming back. If you run the dishwasher daily, once a week is better. It takes two minutes and saves a lot of hassle.
E23
Drain Pump Fault / AquaStop Activated
Dirty water isn't draining — pump blocked or not running
What to Try
- Clean the drain filter first — this is the most common reason the drain pump struggles.
- Check the drain hose for kinks or blockages.
- Look into the pump housing for debris that might be jamming the impeller.
- If the pump itself has failed, it'll need replacing — you can often hear the difference: a healthy pump hums; a dead pump is silent during the drain cycle.
E24
Drainage Problem – Hose / Pump Issue ⭐ Very Common
Machine isn't emptying the water after a cycle
What to Try
- Clean the drain filter — this solves it most of the time.
- Check the drain hose at the back — remove any kinks or bends that might be blocking flow.
- Make sure the drain hose isn't pushed too far down into the waste pipe — it needs an air break to drain freely.
- Check the drain pump impeller for debris.
E25
Drain Pump Blocked / Impeller Jammed
Something is physically stuck in the drain pump
What to Try
- Remove the filter and look into the pump opening with a torch.
- Fish out any debris — broken glass, toothpicks, food waste are the usual suspects.
- Make sure the pump impeller rotates freely once cleared.
- If the impeller is damaged or seized, the pump needs replacing.
E26
Pressure Sensor / Analogue Sensor Fault
The analogue pressure sensor giving wrong or no readings
What to Try
- Power reset first.
- If the code returns, a technician with the right diagnostic tools will need to test the pressure sensor and replace it if faulty.
E27
Mains Voltage Too Low
Not a machine fault — the electrical supply voltage has dropped
What to Try
- Check other appliances on the same circuit.
- Plug the dishwasher directly into a wall socket — not through an extension.
- If the problem is persistent, a voltage stabiliser can protect the machine from fluctuating supply.
- Contact an electrician if you suspect a wiring issue in the property.
E28
Water Flow Sensor Fault
The sensor measuring water flow into the machine has a problem
What to Try
- Check the inlet hose and water supply first — a very restricted water flow can trip this sensor incorrectly.
- If supply and hose are fine, the flow sensor itself likely needs replacing.
❓ Frequently Asked Questions
What does Bosch dishwasher error code E15 mean?
E15 means water has got into the base tray of the dishwasher, triggering the AquaStop flood protection system. You need to tilt the machine carefully to drain the water out, then find and fix the source of the leak before running the machine again.
What does Bosch dishwasher error code E24 mean?
E24 means the dishwasher cannot drain the water properly. The most common cause is a blocked or dirty drain filter — clean it first. Also check the drain hose for kinks and make sure the drain pump impeller isn't jammed by debris.
How do I fix Bosch dishwasher error code E09?
E09 points to a fault with the heating element. Start with a full power reset by switching off at the breaker for 30 seconds. If the code returns, the heating element or its wiring needs professional inspection or replacement.
What does Siemens dishwasher error E22 mean?
E22 on a Siemens dishwasher means the filter is blocked with food and grease. Remove the filter from the bottom of the dishwasher and scrub it thoroughly under running water with a brush. This is a quick, easy fix you can do yourself.
What does Siemens dishwasher error E14 mean?
E14 indicates a fault with the water flow sensor or the filling system. Check that the water inlet hose isn't kinked and the tap is fully open. If the issue keeps coming back, the flow meter may need replacing by a technician.
Can I reset my Bosch or Siemens dishwasher to clear an error code?
Yes — turn off the dishwasher, switch off power at the breaker for 30 seconds, then turn back on. This clears temporary or one-off glitch errors. If the same code comes back, the underlying problem still needs sorting out.
What is the most common Bosch dishwasher error code?
E24 is the most commonly searched Bosch dishwasher error worldwide. It means the machine isn't draining, and in most cases a dirty drain filter is the whole problem. Clean the filter and you'll likely be done in 10 minutes.
What does error E25 mean on a Bosch or Siemens dishwasher?
E25 means the drain pump is blocked or jammed by a foreign object. Remove the filter and check the pump area for debris like broken glass, toothpicks, or food particles and clear them out. If the impeller is still seized after clearing, the pump motor needs replacing.
My Bosch dishwasher shows E01, E02, E03, E04, or E05 — can I fix it myself?
These codes all point to a power module or control board failure. Bosch has locked down the programming of replacement modules, which means even if you buy a new board, you can't program it without dealer-level tools. A reset is worth trying first, but if the code comes back, you'll need a Bosch-certified technician.
How often should I clean my dishwasher filter to avoid error codes?
At least once a month, ideally every two weeks if you run the machine daily. Keeping the filter clean is the single easiest thing you can do to prevent the most common dishwasher error codes — particularly E22 on Siemens and E24 on Bosch.
📅 Last updated: February 2026 | ✍️ Written by the WasherFixers repair team |
Official Bosch support: bosch-home.com
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