Unfortunately you have a blockage in the ducting and/ or in the pump.
Not the easiest to get to (I have the same machine and regularly have to strip it down).
You need to take off the bulged cover on the rear, this exposes the heater, remove the screws holding the heater and then the 3 larger screws holding the drum rear bearing to the back panel.
Next remove all the screws holding the back panel to the appliance, remove the fan (this can be extremely tight and you may have trouble getting it off. Make a note of the wiring on the back panel, disconnect the wires and put the panel aside.
Next remove the fan housing, there are two clips, one top, one bottom, slide these off, remove the screw(s) and take it out.
Clean out the ducting and ensure the small hole into the pump water container is clear.
Next remove the pump and clean out any debris in the container and ensure the pump is clean and clear too. While it's out, use a multimeter and ensure that the pump isn't open circuit on it's coil.
Finally, reverse what's just been done to rebuild your dryer.
You will struggle to get the drum lined up again as you have to fit the backplate to the drum, get the drum into the front bearings and lift the back panel into place and secure it, all at the same time.
You need to allow yourself a few hours to complete this task.
I would point out that this is a major strip down of the appliance. You may want to consider having an engineer come in and do the work. It should take him less around an hour to complete.
If you do decide to do the work yourself, you can always come back here to ask further questions on this fault.
Good luck with your repair.