Bosch Dishwasher Troubleshooting Manual (the ultimate guide)

Bosch dishwashers are known for their reliability, durability and great cleaning performance. But sometimes even Bosch dishwashers develop the odd fault. Which is why we’ve put together this troubleshooting manual.

In this guide you’ll find a description of the fault your Bosch dishwasher is having an issue with as well as the most likely solution to that problem. All of the faults listed in this guide are relatively common and easy to fix so you might want to bookmark this page for future reference.

Common Bosch Dishwasher Faults & Fixes

Below you will find the most common faults found in Bosch dishwashers along with the easy fix solutions.

FaultMost Likely CauseQuick Fix
Dishwasher fails to startNo powerEnsure the plug is fully fitted into the socket and the power is switched on
Dishwasher doesn’t drainBlockage in the drain hose or drain pumpInspect the drain hose for twists, kinks or blockages, clean the drain pump
Dishwasher stops soon after startingBlown thermal fuseInspect the thermal fuse and replace if necessary
Dishwasher cycle doesn’t startDoor not fully latchedEnsure the door is closed and latched properly, if needed replace the door latch
Flashing red light & dishwasher won’t startDoor latch is faultyReplace the door latch
No lights on the control panelPower supply issues or the main control board has shortedMake sure the power supply is uninterrupted, then check the control board for loose connections
Dishwasher displays error code E24Drain pump is cloggedRemove clogs from the drain pump & perform a hard reset to remove the error code
Dishwasher is beeping but won’t startDoor latch or timer faultyCheck the timer for continuity and replace if necessary, replace door latch if it proves to be faulty
Dishes fail to cleanOverloaded dishwasher, detergent dispenser faulty or issues with water supplyEnsure dishes are correctly stacked, check the inlet hose, inlet valve and mains water supply, replace the detergent dispenser
Dishwasher displays error code E15Water leaks of the hose, water tank or sump basinInspect and replace parts as necessary

Dishwasher Fails To Start

If your Bosch dishwasher fails to start, the first thing to check is that you have connected the appliance to the mains electricity. This means checking that the plug is pushed firmly into the wall socket and that the socket is turned on.

If this doesn’t do the trick, try unplugging the dishwasher and plugging something else into that same socket. If the new appliance works then you know it’s not the socket at fault.

Or It Could Be The Door Not Latched Correctly

Another common cause for Bosch dishwashers failing to start is the door not being fully latched. When the door closes correctly on a Bosch dishwasher it creates a seal to prevent any water escaping during the cleaning process.

If the appliance detects that the door is not closed correctly, it will not start. Check for any items however small that could be preventing the door from latching correctly. All it takes is a small piece of food, dirt or other debris to prevent the door from sealing correctly.

It could even be a small piece of glass, a food tie or even a small piece of vegetable matter. Inspect all around the door seal for any objects, however small, that shouldn’t be there and remove them.

Dishwasher Doesn’t Drain

If your Bosch dishwasher fails to drain the dirty water away it means your dishes are sitting in dirty water and won’t come out clean or dry. The most common cause for this is a blocked or twisted drain hose and this is easy to check.

Just inspect the drain hose for any twists or kinks and straighten the hose if there are any. If the hose isn’t twisted, it could have a blockage which will mean removing the hose and using a plumber’s snake to free any blockage.

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If the drain hose is clear, you should check the filter as this could become blocked and prevent the dirty water from leaving the appliance.

If the above are not the cause, the problem is most likely to be with the drain pump which is probably best left to an expert. Or it might be that the drain valve is faulty.

The drain valve will only open if there’s enough pressure behind it to prevent any water from re-entering the dishwasher. If there is any debris blocking the valve it cannot work which could be the problem.

Dishwasher Stops Soon After Starting

If your Bosch dishwasher starts as usual but then suddenly stops it’s most likely to be because of a blown thermal fuse. The thermal fuse is a safety device which detects if the temperature of the dishwasher gets too high and blows to cut the power and prevent any serious damage.

The dishwasher will not restart until a new thermal fuse has been installed. If the thermal fuse does blow, it can sometimes cause the circuit breaker to trip as well. So you’ll need to reset the circuit breaker at the same time as replacing the thermal fuse.

Dishwasher Cycle Doesn’t Start

If your Bosch dishwasher doesn’t start a wash cycle the most likely cause is that the door isn’t fully latched. Check that the racks are in their correct position and that there are no dishes preventing the door from closing.

Then check that the door latch is working correctly and the hinges on the door are working properly too. If necessary, replace the door latch with a new unit.

Another common reason why the wash cycle won’t start is because the child lock has been accidentally activated. The appliance will not start if the child lock has been activated.

Other reasons for your Bosch dishwasher not starting a wash cycle include; not enough water (check the inlet hose and inlet valve) or insufficient drainage (check the drain hose, filter and drain pump).

Flashing Red Light & Dishwasher Won’t Start

If your Bosch dishwasher is displaying a flashing red light and it fails to start, it’s because of a problem with the door latch. This could be as simple as you failed to shut the door correctly in which case the solution is simple.

You should check that there are no dishes obstructing the door or the baskets are sticking out slightly. Once you’ve remedied these issues try to close the dishwasher door again.

If it still doesn’t close correctly, or it seems closed but still displays the red flashing light and won’t start, it could be a faulty door latch or a faulty sensor. These will need checking using a multimeter for continuity and replacing if found to be faulty.

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No Lights On The Control Panel

If there are no lights on the control panel of your Bosch dishwasher it is most probably caused by a lack of power. This could mean the plug has been pulled slightly from the socket or the socket has been switched off.

To fix this simply push the plug fully into the socket and ensure that the wall socket is switched on. Check the circuit breaker to ensure there is power running to the unit and inspect the power cable for any signs of wear.

If all of the above is fine, the problem could be a loose connection to the control board. If none of these apply, you might need to replace the control panel.

Dishwasher Displays Error Code E24

If your Bosch dishwasher is displaying error code E24 it means there’s a problem with drainage. This is more often than not caused by a blockage of some sort either in the drain hose, filter or drain pump.

This is usually caused by a twisted drain hose or a blockage of food or hair in the drain hose or the filter needs cleaning or the drain pump is faulty.

Dishwasher Is Beeping But Won’t Start

This can be very frustrating especially if you’re relying on getting those dishes clean in a hurry. In most cases, it’s an easy fix which just entails making sure the door is closed correctly.

However, it could be due to a faulty door latch, faulty door latch sensor or even an issue with the water supply.

The door latch and sensor will need to be checked for continuity using a multimeter while the water supply could be due to the inlet hose being twisted, the inlet valve developing a fault or the mains water supply turned off.

In some cases, it could be caused if you select an incorrect wash cycle which is another easy fix. Just select the correct wash cycle and restart the appliance.

More serious issues which could cause this fault include; a faulty timer, faulty drive motor or a faulty selector switch.


Dishes Fail To Clean

If the dishes in your Bosch dishwasher fail to clean it could be caused by several things which include;

Dishes Loaded Incorrectly

If you load too many dishes or place dishes too close together, there’s not enough space for water and detergent to get to every item. You might also place items that are too tall in the way of the spray arms which will prevent them from moving correctly and covering each item.

You should always;

  • Place Dishes Correctly
    Arrange plates so that each plate has its own slot and is not blocking the neighbouring plates.
  • Arrange Cutlery Correctly
    Cutlery should be placed in the cutlery basket in an alternate fashion. Placing all the forks or spoons together can result in them clumping together which will prevent them from cleaning correctly.
  • Allow Enough Space For Bowls
    Remember that bowls are likely to fall forwards slightly and block neighbouring bowls from cleaning.
  • Ensure No Dishes Protrude
    Make sure that none of the dishes from one rack protrude onto the adjacent rack which would prevent the spray arm from moving correctly. Ensure that large utensils are placed on the top rack and laid flat to prevent them obstructing the water flow.

Detergent Dispenser Is Faulty

You should always use a high quality detergent in your Bosch dishwasher to ensure all of your dishes get cleaned correctly. If you’re sure the detergent you’re using isn’t the problem, check the detergent dispenser itself. 

If there is any residual detergent left after the cycle has finished, this should be removed. If the dispenser failed to open during the wash cycle it’s very likely to need replacing.

No Water Supply

If your Bosch dishwasher isn’t getting enough water it cannot clean your dishes properly. This can be caused by the inlet hose being twisted, the inlet valve being faulty or the water pressure to your home being low.

Dishwashers need at least 20 Psi of pressure to completely open the inlet valve and ensure a sufficient flow of water to the unit. All British water authorities have to provide a minimum of one bar of pressure to your home. 

One bar of pressure is the equivalent of anywhere between 40 to 60 Psi and is therefore more than enough to run a dishwasher.

If your dishwasher isn’t getting sufficient water to clean the dishes but your home is getting a steady supply, it’s most likely to be a problem with the inlet hose or the inlet valve.

You can inspect the hose for any twists or kinks and once the hose has been straightened, this should solve the problem. 

The inlet valve will need to be checked for continuity using a multimeter and will need to be replaced if found to be faulty.

Dishwasher Displays Error Code E15

If your Bosch dishwasher is displaying error code E15 it indicates that there’s water in the base of the appliance. As well as displaying the E15 error code, the dishwasher will fail to operate. This is because of the anti-flood mechanism which prevents your home from flooding.

Error code E15 indicates a leak somewhere within the appliance. This could be one of the hoses, the water tank or the sump basin. If you feel you have the technical ability to safely dismantle your dishwasher and check for any leaks, you can but we advise you to contact Bosch directly if the appliance is still under warranty or an engineer if not.


Bosch Error Codes

Like all major dishwasher manufacturers, Bosch has a series of error codes designed to notify you of any problems. These codes allow you to identify what the fault is and the most likely way to solve this issue.

We have an article all about Bosch Dishwasher Error Codes which identifies every possible error code you’re likely to find on your Bosch dishwasher and gives the solutions to these problems. Simply follow the link for a comprehensive list of all Bosch dishwasher error codes and ways to solve any issues.

How To Reset A Bosch Dishwasher

There are 2 ways to reset a Bosch dishwasher to clear a fault code which are;

  1. Soft Reset
    To perform a soft reset all you need to do is press and hold the “start” button for 3 to 5 seconds. This is often enough to clear the programme and reset the appliance.
  2. Hard Reset
    If a soft reset doesn’t clear the error code or fault with your Bosch dishwasher, you should; Remove the plug from the wall socket for at least 10 to 15 minutes. Then plug it back in and turn on the wall socket. The appliance should now be fully restored to usual operations and any temporary memory should also have been cleared.

SEE ALSO: Bosch Dishwasher No Lights On Control Panel? (here’s why & how to fix)

Frequently Asked Questions

What is the most common fault with a Bosch dishwasher?

The most common fault with a Bosch dishwasher is not cleaning dishes properly. This can be caused because the filter needs cleaning, the dishes are stacked poorly, using a low quality detergent or insufficient water pressure.

Why is my Bosch dishwasher not starting but has power?

If your Bosch dishwasher has power but won’t start it could be because there is insufficient water. This can be caused by low water pressure from the supply, a twisted inlet hose or a faulty inlet valve.

Why is my Bosch dishwasher flashing a red light but won’t start?

If your Bosch dishwasher is displaying a flashing red light and won’t start, the most likely cause is the door isn’t closed correctly. Check that there are no obstructions preventing the door from closing properly. This could be a large dish sticking out, the rack not pushed in fully or an item of food etc stuck in the door. Alternatively, it could be that the door latch or door sensor are faulty.

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