Black streaks and marks on white washing

[Longman S]

I keep getting black streaks and marks on white washing from my Bosch washing machine / tumble dryer. I have has a service engineer come out and he could not find the reason replaced the door seal. First was after this and it happened again on a pair of cream denim trousers. The machine is 1 year old.  and this started about 6 months ago. Has anyone else had this happen 

[Whitegoodshelp]

On 27/11/2021 at 22:36, Longman S said:

black streaks and marks on white washing from my Bosch washing machine / tumble dryer

Hello Susan. Do you mean it is a washer-dryer or that you aren't sure if it is the washing machine or the tumble dryer? I'm presuming it is a washer dryer?

Can you tell me what wash cycle you use most and its temperature? And do you use liquid detergent?

[Longman S]

Hi Andy it is a washer/dryer. This has happened on various washes usual temp is either 30degree Cotton and 60degree cotton Gentle dry. Yes I used to use non bio liquid.  Thanks

[Whitegoodshelp]

Hi. Using mostly 30 degree washes and liquid detergent can cause a big build up of grease, grime and even black mould inside washing machine. 

Was the door seal that got replaced covered in gunge? Also have a look under the door seal under the lip of the revolving drum to see if there is any nasty stuff. 

[Longman S]

No the engineer said it was very clean and clear of fluff or anything. Drum checked and no gunk also I use Bosch cleaner every 2 months. The marking doesn’t happen on every wash, also I now use laundry strips. 

[Whitegoodshelp]

Tbh it does normally take a few years to get bad. If washing machine is nice and clean it’s hard to imagine where black marks could come from. 
 

Washer-dryers have a vent at the top of the door seal where the hot air for drying is blown into the drum. It’s very common for laundry to get caught on it especially if overloaded. Try rubbing a light cloth around up there to see if you can find anything. 
 

Other than that I can only point you to my article washing not getting clean or has marks on it in case it has anything useful. 

[Whitegoodshelp]

If you could post any photos it might help too. 

[Longman S]

[Longman S]

Hi Andy Have tried that. The machine is not a year old yet and only gets used Twice a week

[Whitegoodshelp]

Try getting an old light coloured sheet or cloth and see if you can replicate the marks by dragging it firmly around the door seal where it meets the lip of the drum and up at the top where the vent for the dryer is. 
 

Essentially, as the laundry is inside a steel drum and the marks are long it can only really be caused by laundry getting trapped and dragged around the door seal. 
 

It seems to be common in washer-dryers though manufacturers usually blame overloading.