As per what Bob said-its inside the machine which is a pain to get at,but to be honest-unless you cool wash 99% of the time with incredibly dirty and gritty clothes you shouldnt have any blockage problems.
Its not excally a filter,but more of a 'trap' to catch debris.After 4.5 years i decided to check mine and all i found was 25p (yes really!) and a small amount of dirt which to be honest would have dissapeared next time i did a hot wash.
I guess Ariston stuck it inside the machine because its not something which should need removing regulary-if at all.I cant fault my particular washing machine because it works faultlessly,is ultra quiet and does a good job.
Stevie weevey
December 2009