Servis M9614 washer dryer top removal? ?

The dryer on my machine has suddenly stopped giving out heat. I have read that if I remove the top I need to press a red button on the heater to get it working again. But I can't get the top off. I have removed the two long screws on either side - there isn't one in the middle - but there is something stopping the top from lifting on the side over the cold water pipe inlet. I can't see what else there is to undo.
Thanks