Problem with a built-in Boasch washing machine

[bobjane]

Has any one else got this problem?
I have an expensive Built in bosh washing machine (WLF 12440GB/17)
About eighteen months old. In every wash I get black sticky bits coming out on my "clean" washing. It appears to be a type of mould coming from under or behind the drum.
I have had engineers come out - under extended guarnatee - but they say they can find nothing wrong!
Help

 

[HANDSON]

Try descaling your machine. Sounds like u have bits of scum from the inner bowl coming loose.hope this helps

 

[bobjane]

Thank you for your very prompt reply to my problem. I should have mentioned when I got a repair chap in - under the extended warranty - he said he could find no problem but insisted I purchase from him an industrial strenght descaler. He set the washing machine on 90c to give it a good clean which took hours. At the end the drum was full of sticky black bit which took ages to clear out. However, I have done lots of washes since and still get some bits on all washes!
Really I would be happier to get this machine replaced, but don't know whether it is an option now?