www.dyson.co.uk
www.dyson.com
Select your correct model there are lots of DCO7's. click support and follow through the fault on not sucking.
It could be the filter/s my daughters stopped sucking [DC05 cylinder] even though she washed the filter I vaccumed both filters with my panasonic and hey presto when fiters return to machine the suction was brilliant just like new.
Bob, September 2010