WAU28T51GB/01 won't drain

[phil21]

Hello I was just wondering if there are any other issues that would stop a bosch washing machine to not drain.

I keep getting an error code of E36/10. I have cleaned out the filter cleaned out the hose checked the pump and it's still running but the water still won't drain.

The black hose from the bottom of the machine to the pump is also clear apart from the small ball which I presume acts as some non return valve.

I would appreciate any advice on this cheers in advance 

[Whitegoodshelp]

Hi. Yes the ball acts like a one way valve to stop detergent leaving the drum and going into the sump hose. Make sure it is clean and not covered in a sticky gunge that can cause it to stick and seal off the water inside the drum. 

Other than that my article on Whitegoodshelp is very comprehensive and covers all possibilities. Make sure you go through it methodically and also read the other articles linked to inside it 

How to fix not draining water on washing machine

[phil21]

37 minutes ago, Whitegoodshelp (Andy) said:

Hi. Yes the ball acts like a one way valve to stop detergent leaving the drum and going into the sump hose. Make sure it is clean and not covered in a sticky gunge that can cause it to stick and seal off the water inside the drum. 

Other than that my article on Whitegoodshelp is very comprehensive and covers all possibilities. Make sure you go through it methodically and also read the other articles linked to inside it 

How to fix not draining water on washing machine

Cheers Andy I will give it a read and go through it.

I will let you know how I get on 

[phil21]

Well Andy I tried everything cleaned out the filter cleaned out the waste pipe  cleaned the pipe at the bottom of the drum and tried a cycle but no joy. The pump seems to be running but I have no multi meter to test I have ordered a new pump and I am hoping its that. Cheers for the advice Andy and I will let you know if it's the pump

[Whitegoodshelp]

Hi. The pump is only faulty if it doesn't run at all, (even then it could be due to other faults) or if the pump impeller is broken. Both of which can easily be checked. There is nothing else that could cause a pump to not pump out if it is running. They either run or not. 

You should be able to work out the cause by process of elimination using my articles. 

[Whitegoodshelp]

If the pump is running it must pump water unless -

The sump ball is stuck preventing water getting into the pump

The pump impeller is broken or loose on the shaft and therefore not creating the pumping 

There is a blockage inside the pump

The drain hose has a blockage inside

The spigot that the drain hose is connected to under the sink has a blockage inside

[phil21]

If the ball was stuck would you be able to drain the drum from the drain at the front 

[Whitegoodshelp]

If the ball was stuck, water would be trapped inside the drum, and wouldn't get into the sump hose and pump. So no. 

[phil21]

29 minutes ago, Whitegoodshelp (Andy) said:

If the ball was stuck, water would be trapped inside the drum, and wouldn't get into the sump hose and pump. So no. 

The water will drain out of the small hose so I am left scratching my head 🙃 

[Whitegoodshelp]

Have you removed the drain hose and checked for blockages and checked the plastic spiggot on the u bend and the bit that pushes into the drain hose?

I presume you‘ve already checked inside the pump for obstructions. 

I listed 5 possible causes for pump apparently running OK but not pumping water. If you've checked the ones I‘ve just mentioned that only leaves a faulty pump. 

Fault finding is 90% process of elimination. 

[phil21]

2 hours ago, Whitegoodshelp (Andy) said:

Have you removed the drain hose and checked for blockages and checked the plastic spiggot on the u bend and the bit that pushes into the drain hose?

I presume you‘ve already checked inside the pump for obstructions. 

I listed 5 possible causes for pump apparently running OK but not pumping water. If you've checked the ones I‘ve just mentioned that only leaves a faulty pump. 

Fault finding is 90% process of elimination. 

Yea done all of the above I have a new pump arriving tomorrow so I will let you know then 😏 

[phil21]

On 09/03/2025 at 16:06, phil21 said:

Yea done all of the above I have a new pump arriving tomorrow so I will let you know then 😏 

Well Andy still no joy still getting the e36/10 error code 😕  I left the top off this time while doing a test run and noticed a leak on the drain hose so I am still at a loss why It won't pump out 

[Whitegoodshelp]

Have you fitted new pump?

[phil21]

1 minute ago, Whitegoodshelp (Andy) said:

Have you fitted new pump?

Yea new pump fitted

[Whitegoodshelp]

Have you confirmed that the pumps are definitely running?

[phil21]

Just now, Whitegoodshelp (Andy) said:

Have you confirmed that the pumps are definitely running?

Yea ran it before doing a test run 

[Whitegoodshelp]

To be honest it should be really easy to get to the bottom of this. The only thing that could possibly prevent pumping water is if no water is getting into the pump, or there is a blockage inside the pump, inside the drain hose, or at the u-bend. 

Tests for these things are -

1: Disconnect drain hose from u-bend and hold end of drain hose into a bucket or bowl around chair height or worktop height. 

If it pumps out the spigot in u-bend is blocked. If it doesn't, the u-bend is eliminated. 

2; Lower the drain hose into a washing up bowl. Water should siphon out indicating water can get from the drum to the pump. 

3: Take off drain hose and stretch it out to make sure you can see clearly all the way through it. Try pushing one end up to a tap and turn it on to make sure water gets through. It's been known for small button to jam inside and swing open and shut acting like a butterfly valve. 

 

 

 

 

[Whitegoodshelp]

Another thing to check is to drain all the water out and open the pump filter and take the filter out. You should be able to see the pump impeller. Put the machine on a drain cycle and see if you can confirm the impeller is spinning round at pace.

If you ran the pump externally first and already checked that it won't be necessary. 

 

[phil21]

2 minutes ago, Whitegoodshelp (Andy) said:

To be honest it should be really easy to get to the bottom of this. The only thing that could possibly prevent pumping water is if no water is getting into the pump, or there is a blockage inside the pump, inside the drain hose, or at the u-bend. 

Tests for these things are -

1: Disconnect drain hose from u-bend and hold end of drain hose into a bucket or bowl around chair height or worktop height. 

If it pumps out the spigot in u-bend is blocked. If it doesn't, the u-bend is eliminated. 

2; Lower the drain hose into a washing up bowl. Water should siphon out indicating water can get from the drum to the pump. 

3: Take off drain hose and stretch it out to make sure you can see clearly all the way through it. Try pushing one end up to a tap and turn it on to make sure water gets through. It's been known for small button to jam inside and swing open and shut acting like a butterfly valve. 

 

 

 

 

Cheers Andy I will try that now I do have a small leak from the drain hose so I will have to order a new one 

[phil21]

31 minutes ago, phil21 said:

Cheers Andy I will try that now I do have a small leak from the drain hose so I will have to order a new one 

Well Andy I took the drain pipe of and it did pump out water the hose is connected to a sink and I have checked the sink bends and cleaned them before. I really don't know what's going on and it's after going through a rinse and drain cycle and all good. There is a leak in the drain pipe so that will need replacing. I will order that and fit it and let you know the outcome.

Thanks for all your help and advice Andy I really appreciate it 👍 

[Whitegoodshelp]

Its not a new or replacement u-bend is it? Or the first time you've connected it up there?

[phil21]

Just now, Whitegoodshelp (Andy) said:

Its not a new or replacement u-bend is it? Or the first time you've connected it up there?

No it was always connected there that what strange 

[Whitegoodshelp]

Its just that new u-bends are blanked off and need something removing or cutting off before connecting a drain hose. 

 

[phil21]

Just now, Whitegoodshelp (Andy) said:

Its just that new u-bends are blanked off and need something removing or cutting off before connecting a drain hose. 

 

Ah cheers no old connection