These machines are well made with a complex design but it is a floored design. The cyclone filter cones in the canister build up with dirt and so do the smaller cyclone chambers on top causing it to LOSE SUCTION!
I found Bev’s question 12 months after she posted it, don’t know how she got on, but after much searching the net I found the secret.
To Pull Apart the DC11 Cyclone section there are three more screws! To get to them you need to remove the button (the one that unlocks the flap to empty the dust out) There is a hole on the other side of the button, when you push on the button you will se the end of the button which has a barb holding said button in, pushing a narrow (3 mm) but longish screwdriver into it will release the button this will reveal one of the three remaining screws, remove screw and handle and reveal the remaining two.
BEWARE this starts to get complicated, there are 2 spring loaded catches crossing through each other that need to be reassembled when reassembling the unit.
Before removing final screws remove the canister s’ or (bin s’) rubber gasket first, this holds the 2 cyclones together and may tear if not removed.
On reassembling you fit 1 of the cyclones to the top housing first so you can reassemble the spring loaded catches, only 1 side is capable of holding the springs and catches. Before you screw in the other cyclone you need to refit the rubber gasket to both cyclones, then wriggle the other cyclone into position and screw up, DON’T over tighten and strip the plastic holes! Best of British to you!
James
September 2010