How to fix an E24 error in a Bosch dishwasher? Step description.

My experience with the constant error E24 of a ten year old Bosch dishwasher:
1) I removed the filter, the one that unlocks with a teaspoon, and checked with my finger if there were "foreign bodies" in there and if the impeller was turning - everything was OK;

2) I checked the patency of the dishwasher drain hose connected to the kitchen sink trap. It was a little stained at the end, but this did not result in an E24 error.

3) Next step - I removed the pump pumping water out of the dishwasher. There were (I don't know how this was possible) some odd pieces of foil, string and other rubbish wound up on the impeller, but the impeller turned without a problem. After cleaning the impeller, I fitted the pump to the dishwasher and checked that it was pumping water out by pouring water with a dish directly into the bottom of the dishwasher and starting a short programme. Everything was OK.

4) The next step is to check that the dishwasher is drawing water.
The easiest way to do this is to remove (take out) the water supply hose to the dishwasher, but only on the dishwasher side. After removing the hose and disconnecting the power supply (undoing the power cube), I inserted the hose into the bowl and applied power to the hose (electro-valve) directly from the 230V socket. The electro-valve worked correctly because water was pouring into the bowl when power was applied. So everything is OK again.

5) The next step was the pump-heater i.e. checking the plain bearings.
I dismantled it and looked at the bearing motor. The plain bearings had oval holes (exactly as someone of you described this problem on the forum). With the plain bearings out with a caliper I checked all the dimensions carefully and started looking for new bearings on Allegro. What was my surprise that nothing fitted from Bosch, but I found one from Beko. The cost of the plain bearings was £50.00 excluding postage. After replacing the plain bearings the dishwasher is running like new.

By the way, I found a video on Youtube that allowed me to "get to" the pump that pumps out the water and the pump-heater.
The biggest problem is removing the impeller from the pump-heater in order to get to the plain bearings. First you have to "unbolt-separate" the motor from the turbine housing. Once you have done this you will have access to the turbine seated (bolted - note - left) directly on the engine rotor. And this is where the 'stairs' begin. You won't unscrew the turbine because you have no direct access to the rotor and can't immobilise it in any way. I decided to remove the rotor together with the turbine with two flathead screwdrivers, putting them underneath the turbine on the rotor side.
First push in some smaller flat screwdriver and bend the turbine just enough to insert a larger screwdriver. The turbine is plastic and will bend. On the opposite side of the turbine, pry up the other screwdriver in the same way and hey up. Once you have removed the rotor you will need to unscrew the turbine REMEMBER the left hand thread.
NOTE - DO NOT insert screwdrivers into the turbine slots or you will ruin the turbine.
Colleagues thank you for your hints and I wish you the best of luck.

markus_m wrote:

You won't unscrew the turbine because you don't have direct access to the rotor and can't immobilise it in any way. I decided to remove the rotor together with the turbine with two flathead screwdrivers, putting them underneath the turbine on the rotor side.
First push in some smaller flat screwdriver and bend the turbine just enough to insert a larger screwdriver. The turbine is plastic and will bend. On the opposite side of the turbine, pry up the other screwdriver in the same way and hey up. Once you have removed the rotor you will need to unscrew the turbine REMEMBER the left hand thread.
NOTE - DO NOT insert screwdrivers into the turbine slots or you will ruin the turbine.
Colleagues thank you for your hints and good luck.

.

I have done the bearing replacement several times.
There are two methods of getting at the rotor and consequently the bearings, both effective.
The first is to remove the stator and hold the rotor through the housing with a strong neodymium magnet.
Turning the turbine with the rotor locked in this way unscrews it with no problem. Knowing that the thread is left-handed is crucial.

The second method is to knock out the impeller inertially by skilfully striking the pump casing against the base
with a round hole with a diameter larger than the impeller turbine.
This method is good especially if you have tried the previous method to "unscrew" by turning clockwise.

Once the impeller has been knocked out, the turbine is unscrewed in the classic manner by holding the impeller.

And isn't it simpler to buy a new pump-heater for £249 than fiddle around for half a day repairing it? I understand if it was more expensive, yes, but the prices of these pump-heaters have come down recently that it pays to replace the whole component.