Bosch Condenser dryer WTE84105GB not pumping all the time

[mikeyman76]

Hi Everyone

I have a Bosch condenser tumble dryer model number WTE84105GB thats 5 years old now.

Its suddenly developed a problem of not always pumping the condensate to the waste water container when it should. I have cleaned out the sump and checked the pump is running and can run freely, i have also checked that all the hoses are clear of any sludge.

Ive noticed on the internet that some Bosch models of this type use a float to detect water level in the sump, this model uses two metal strips moulded into an assembly, i have checked that these are clean too. But not knowing how exactly they detect water level, i can’t test it.

Does the pump motor have a thermal cutout and isn’t running when it gets told by the sensor it should or is the water level sensor faulty and not telling the motor to run , or it the control board faulty and getting the correct information, but just not telling the pump to run.

The pump runs perfectly well, as when first switched on it pumps and water can be seen doing into the waste container.

Could you tell me if this is a common problem and what part i need to fix it. It was quite a pricey dryer when new and being a premium brand, i would be quite annoyed if its cheaper to buy new than fix this one.

Cheers

Mike

[Martin]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

You need to replace the pump. At 5 yrs old it’ll be worn out.

[mikeyman76]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi Martin

5 years and the pump needs replacing? Seems a bit poor for Bosch. This machine is only ever used for 3 or 4 loads a week max and usually only in spring, autumn and winter.

I think what i will do is take the side off the machine again and watch it to see where the water is coming from and see if voltage is being applied to the pump when it ought to be pumping (calm down H&S freaks – im an electronic engineer). If i were to need a new pump or water lever sensor assembly, could anyone tell me the part numbers i would need and where i might even get the parts.

Many thanks

Mike

[Martin]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

mikeyman76 wrote:Hi Martin

5 years and the pump needs replacing? Seems a bit poor for Bosch.

I admire your faith in Bosch products

mikeyman76 wrote:could anyone tell me the part numbers i would need and where i might even get the parts.

Check out this link: –
http://www.bosch-home.co.uk/store/product/Pump/00497217

[mikeyman76]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi Martin

Thanks for the like, thats exactly the assembly i would need to buy. Glad it all comes as a complete assembly with the water level sensor too.

Ill probably end up buying the part, but im still interested as to what is worn on the motor to stop it pumping.

Cheers

Mike

[mikethemechanic]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

hi just another check when you say you’ve cleared the sump did this involve taking the condenser out and removing the flap in the centre? or have you just cleared what is under the pump assembly?

[mikeyman76]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi Mike

I did indeed take the condensor out and lifted the plastic flap and cleaned out under there too. It really wasnt that silted up, mind you its the second time i have had to check it in 5 years, the previous time i just kept getting the light coming on telling me to empty the water container.
So this is a different fault.

One thought i did have was what i will refer to as ‘green spot’ it happens a lot in electronic fault finding in wound components (coils, transformers, chokes etc) Its where the emamel coating on the winding wire fails and the copper wire then oxidises and the wire breaks. Almost always this will happen when a piece of equipment is stored in a damp environment.

Well thinking about it, the motor is mounted above a tank of water, the machine lives in the garage and for certain months of the year it sits there not getting any use, so i wonder if the damp, the hot and cold cycling and months of no use have had an adverse effect on the motor winding.

The motor terminals are probably soldered with the dreadful lead free solder, which is notorious for going dry jointed. So ill check them too.

Im sure its all academic and ill find noting amis and a new part will cure the fault entirely.

Cheers

Mike

[mikethemechanic]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi maybe on a few occasions if it has a small relay module behind the main control module I have found this to solve the problem but in the senario of this being faulty it will say the containers full but when u check the sump there is no water in there it’s also usually very intermittent when I have had this be the problem so when it doesn’t pump is there water in the sump?
I take it the container full light is coming on ?

[mikeyman76]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi Mike

No the ‘container full’ light doesnt come on. It just fails to pump and water ends up all over the floor.

Mike

[mikeyman76]

Re: Bosch Condenser dryer WTE84105GB not pumping all the tim

Hi all

Well I had another look at the dryer and I can confirm that there is nothing wring with the pump. As I was monitoring it on a drying cycle the pump was cutting in and out and pumping as it should and lo and behold a pool of water started appearing.

I stood the dryer up on some blocks and could see that the water was coming from under the machine. On pulling the condenser out and lifting the plastic flap I could see that the condensed water has to flow through a small opening into the sump. This was blocked with a small but of fluff. Very difficult to see, but once cleared it all worked perfectly with no more pools of water on the floor.

Thanks very much for all your help with this guys.

Mike

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