My Miele Cat & Dog 700 started to produce a high pitched loud noise - does not affect pick up quality - still good. Bag does not need emptying or anything like that, though exhaust filter could do with replacing. Is something on its way out? It's about ten years old.
We have a Cat n Dog model and for last month only after turning it off the machine makes an awful noise as the motor slows. We found if we remove the HEPA filter and run the machine there is no noise when turning the machine off. Pleased to have identified the cause. unsure what within the HEPA filter is making the noise. the machine itself is no more than 6 months old.