Hello, I have the same dryer and after a bit of digging (since I lost the manual) I found the answer.
You need to clean the filter which on this machine is on the bottom front of the dryer. It's a bit tricky to find out how to open the bottom drawer but here's my best stab at explaining it.
When you open the front door there is a small circular button/latch to the bottom right of the opening. If you push this it frees up the panel "locks" so you can open it. I kept pulling the button instead of pushing but once I pressed it in, the panel just popped open.
At the bottom left you will see a silver filter-like thing with 2 blue latches holding it in place. Rotate the blue latches and it will let you pull out the filter. Mine was covered in muck and the instructions say to just use water to clean.
Since doing this, it has worked a dream (again).
If it helps I found the manual for the machine but only in French, German or Italian but at least the images helped... https://portal.bsh-partner.com/portal(bD1lbiZjPTAwOQ==)/PORTALFRAME.HTM
Hope this works for you.
Cathy, March 2009